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Li N, Wang C, Yang M, Chen D, Tang M, Li D, Qiu S, Chen Q, Feng Y. Effects of different tooth movement patterns and aligner thicknesses on maxillary arch expansion with clear aligners: a three-dimensional finite element study. Front Bioeng Biotechnol 2024; 12:1424319. [PMID: 38983604 PMCID: PMC11231920 DOI: 10.3389/fbioe.2024.1424319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024] Open
Abstract
Objectives The objective of this study was to investigate the biomechanical effects of different tooth movement patterns and aligner thicknesses on teeth and periodontal tissues during maxillary arch expansion with clear aligners, to facilitate more precise and efficient clinical orthodontic treatments. Methods Three-dimensional models including teeth, maxilla, periodontal ligament, and aligner were constructed and subjected to finite element analysis. Tooth displacement trends and periodontal ligament stresses were measured for seven tooth displacement patterns (divided into three categories including overall movement of premolars and molars with gradually increasing molar expansion in each step; distributed movement of premolars and molars; and alternating movement between premolars and molars at intervals) and two aligner thicknesses (0.5 mm and 0.75 mm) during maxillary arch expansion with clear aligners. Results When expanding the maxillary arch with clear aligners, the effective expansion of the target teeth mainly showed a tilting movement trend. Increasing the amount of molar expansion increased the buccal displacement of the first molar but decreased the buccal displacement of the premolars. The mean buccal displacement of the target teeth was greater in the posterior teeth interval alternating movement group (0.026 mm) than in the premolar/molar distributed movement group (0.016 mm) and the overall movement group (0.015 mm). Increasing aligner thickness resulted in greater buccal displacement of the crowns and increased stress on the periodontal ligaments. Conclusion Increasing the amount of molar expansion reduces the efficiency of premolar expansion. Alternating movement of premolars and molars at intervals achieves a higher arch expansion efficiency, but attention should be paid to the anchorage of adjacent teeth. Increasing the thickness of the aligner increases the expansion efficiency but may also increase the burden on the periodontal tissues.
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Affiliation(s)
- Na Li
- Silk Crossing Clinic, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - ChunJuan Wang
- Chongqing Key Laboratory of Oral Diseases, Chongqing Municipal Key Laboratory of Stomatological Biomedical Engineering, Chongqing, China
| | - Min Yang
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - DingGen Chen
- Silk Crossing Clinic, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - MingYuan Tang
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - DaoKun Li
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - ShengLei Qiu
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - Qi Chen
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - Yi Feng
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
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Chen J, Zhu D, Zhao M, Cheng Z, Pan Y, Liu X. Three-dimensional finite element analysis of the optimal mechanical design for maximum inward movement of the anterior teeth with clear aligners. Sci Rep 2024; 14:13203. [PMID: 38851833 PMCID: PMC11162411 DOI: 10.1038/s41598-024-63907-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 06/03/2024] [Indexed: 06/10/2024] Open
Abstract
This study aims to refine clinical designs within clear aligner therapy, exploring the appropriate ratio of anterior tooth retraction to intrusion under maximum anchorage. Using a three-dimensional finite element model and evaluating 19 load scenarios with first premolar extraction, the research identifies the optimal force angle for anterior tooth retraction as 45 to 55°. For clinical planning, it is recommended to design a retraction of 0.19 mm combined with an intrusion of 0.16 mm to achieve anterior tooth retraction. This investigation is crucial for enhancing understanding of biomechanical principles in clear aligner orthodontics, offering significant insights for effective treatments.
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Affiliation(s)
- Jingcheng Chen
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Daoyu Zhu
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Mengli Zhao
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Bengbu Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Zhiheng Cheng
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Wanan Medical College, Wuhu, 241000, Anhui, People's Republic of China
| | - Yan Pan
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China
- Hefei Dental Clinical College of Anhui Medical University, Hefei, 230000, Anhui, People's Republic of China
| | - Xin Liu
- Hefei Stomatological Hospital, Hefei, 230000, Anhui, People's Republic of China.
- Hefei Dental Clinical College of Anhui Medical University, Hefei, 230000, Anhui, People's Republic of China.
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Sadek MM, Alhashmi R. Unplanned tooth movement in deepbite correction with Invisalign: A retrospective study. J World Fed Orthod 2024; 13:136-144. [PMID: 38402054 DOI: 10.1016/j.ejwf.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/24/2023] [Accepted: 12/13/2023] [Indexed: 02/26/2024]
Abstract
BACKGROUND This study aimed to investigate unplanned tooth movements in deepbite correction with Invisalign. METHODS The sample consisted of 34 adult patients with deepbite malocclusion treated with Invisalign. Pretreatment and predicted digital models were exported from ClinCheck software, while the post-treatment model was obtained from an intraoral scan taken at the end of the first set of aligners. Digital models' superimposition was done using the eModel "Compare" software. Frequency and percentage of occurrence of unplanned linear and angular movements, their magnitude, and direction were then determined. In addition, comparison of unplanned movements was performed between anterior and posterior teeth as well as between linear and angular measurements. RESULTS The percentage of unplanned movements ranged from 1.68% to 25.63% in the maxilla and 3.36% to 23.95% in the mandible, being most evident in the first and second molars. Unplanned movements were statistically significantly more frequent in posterior teeth compared with the anterior teeth (P > 0.05). In addition, the frequency of angular movements was statistically significantly higher for each tooth than linear movement (P < 0.05) with a higher mean value. Unplanned mesiodistal movements were the least frequent. CONCLUSIONS Unplanned linear as well as angular movements were evident in almost all teeth. Unplanned faciolingual inclination and mesiodistal angulation movements were the most frequently observed. Unplanned vertical movements can affect the predictability of deepbite correction and thus merit particular attention in those cases.
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Affiliation(s)
- Mais M Sadek
- Assistant Professor, Department of Orthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt; Assistant Professor of Orthodontics, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates.
| | - Reem Alhashmi
- Orthodontic Resident, College of Dental Medicine, University of Sharjah, United Arab Emirates
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Caldas W, Bonin FA, Piscinini JLM, Vianna CP, Shimizu RH, Trojan LC. Evaluation of the success of predicted dental changes with clear-aligner treatment: A pilot study. Saudi Dent J 2024; 36:708-711. [PMID: 38766278 PMCID: PMC11096612 DOI: 10.1016/j.sdentj.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 05/22/2024] Open
Abstract
Objective This pilot study concerned evaluation of the success of predicted dental changes in patients presenting with Class I malocclusions who were submitted to treatment aligners, using the superimposition. Methods The digital models were superimposed and analyzed using 3DSlicer 5.0 software. Treatment and predicted changes regarding horizontal and vertical linear displacements, mesiodistal rotations, and incisor buccolingual tipping were quantified. The success rates were calculated by dividing the mean treatment change amount by the predicted change amount. Results Lower-incisor intrusion was the most accurate of the predicted vertical displacements (86.96 %), and buccal expansion of upper canines (99.32 %) and mesial translation of the lower incisors (98.57 %) were the most accurate horizontal linear displacements. The predicted rotation was achieved with the highest accuracy for lower incisors (75.69 %). Incisor buccolingual tipping success rates ranged between 45.78 % and 69.31 %. Low accuracy of predicted changes was found for upper-molar extrusion (10.23 %) and constriction (8.91 %). However, minimal corrections in these directions were planned. Conclusions Dental changes for all regions of maxillary and mandibular arches could be evaluated. High success rates were observed for most of the movements planned for ClearCorrect aligner therapy.
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Castroflorio T, Parrini S, Rossini G. Aligner biomechanics: Where we are now and where we are heading for. J World Fed Orthod 2024; 13:57-64. [PMID: 38228450 DOI: 10.1016/j.ejwf.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 12/07/2023] [Indexed: 01/18/2024]
Abstract
Aligner orthodontics has gained significant popularity as an alternative to traditional braces because of its aesthetic appeal and comfort. The biomechanical principles that underlie aligner orthodontics play a crucial role in achieving successful outcomes. The biomechanics of aligner orthodontics revolve around controlled force application, tooth movement, and tissue response. Efficient biomechanics in aligner orthodontics involves consideration of attachment design and optimized force systems. Attachments are tooth-colored shapes bonded to teeth, aiding in torque, rotation, and extrusion movements. Optimized force systems ensure that forces are directed along the desired movement path, reducing unnecessary strain on surrounding tissues. Understanding and manipulating the biomechanics of aligner orthodontics is essential for orthodontists to achieve optimal treatment outcomes. This approach requires careful treatment planning, considering the mechanics required for each patient's specific malocclusion. As aligner orthodontics continues to evolve, advances in material science and treatment planning software contribute to refining biomechanical strategies, enhancing treatment efficiency, and expanding the scope of cases that can be successfully treated with aligners.
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Affiliation(s)
| | - Simone Parrini
- Research Assistant, Department of Orthodontics, Dental School, University of Turin, Turin, Italy
| | - Gabriele Rossini
- Board Director, Clear Aligner Academy Italia, Turin, Italy; Private Practice, Milan, Italy
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Zhao W, Lou Y, Yan W. Evaluation of stress and displacement of maxillary canine during the single canine retraction in the maxillary first premolar extraction cases- A finite element study. Clin Oral Investig 2024; 28:206. [PMID: 38459220 DOI: 10.1007/s00784-024-05590-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/25/2024] [Indexed: 03/10/2024]
Abstract
OBJECTIVES This finite element study aimed to simulate maxillary canine movement during anterior teeth retraction. MATERIALS AND METHODS Three methods of maxillary canine movement including miniscrew sliding with high hooks (MSH), miniscrew sliding with low hooks (MSL), and the traditional sliding method (TS) without using miniscrews were simulated using three-dimensional finite element analysis. The initial displacement of the maxillary canine, the maximum principal stress of the periodontal ligament and the Von Mises stress were calculated. RESULTS The distolingual tipping movements of the canine were shown in three movement modes. MSH showed a small tendency to lingual tipping movement and a extrusion movement while MSL had the largest lingual inclination. TS demonstrated a tendency toward distolingual torsion displacement. Compressive stress values were mainly concentrated in the range - 0.003 to -0.006 MPa. For tensile stress, the distribution of MSH and MSL was concentrated in the range 0.005 to 0.009 MPa, TS was mainly distributed about 0.003 MPa. Von Mises equivalent stress distribution showed no significant difference. CONCLUSIONS The loss of tooth torque was inevitable, irrespective of which method was used to close the extraction space. However, miniscrew application and higher hooks reduced the loss of torque and avoided lingual rotation. CLINICAL RELEVANCE This study shows that miniscrew implants with different hooks can better control the movement of the maxillary canines. The non-invasive nature of the finite element analysis and its good simulation of dental stress and instantaneous motion trend have a clinical advantage in the analysis of tooth movement.
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Affiliation(s)
- Wenbo Zhao
- School of Stomatology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, 150000, China
| | - Yu Lou
- School of Stomatology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, 150000, China
| | - Weijun Yan
- School of Stomatology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, 150000, China.
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Anh NV, Duc NM, Tra NT, Ngoc VTN, Son TM. Lingual bracket transfer accuracy of double vacuum-formed indirect bonding tray using 3D-printed model: an in vivo study. Am J Orthod Dentofacial Orthop 2024; 165:294-302. [PMID: 37906244 DOI: 10.1016/j.ajodo.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/01/2023] [Accepted: 09/01/2023] [Indexed: 11/02/2023]
Abstract
INTRODUCTION This study aimed to assess the transfer accuracy of a digital indirect bonding method for lingual brackets using double vacuum-formed trays in vivo. METHODS Twenty-five patients in need of lingual orthodontic treatment were consecutively recruited. Bracket placement was performed on ideal setups, followed by fabricating indirect bonding trays through vacuum-forming on 3-dimensional printed models. Transfer accuracy was measured at each bracket after superimpositions of postbonding scans and reference data. One-tailed t tests were used to determine whether bracket deviations were within the limit of 0.5 mm and 2° for linear and angular dimensions, respectively. RESULTS A total of 611 lingual brackets were evaluated. Mean linear transfer errors were 0.06 mm, 0.09 mm, and 0.12 mm, with frequencies of deviations within the 0.5 mm limit of 99.7%, 99.8%, and 98.0% for mesiodistal, buccolingual, and occlusogingival dimensions, respectively. Regarding angular measurements, mean transfer errors were 1.28°, 1.73°, and 2.96°, with frequencies of deviations within the 2° limit of 81.0%, 68.9%, and 51.1% for rotation, tip, and torque, respectively. Mean errors fell within the clinically accepted limits for all linear dimensions and rotation but exceeded the limit for tip and torque. CONCLUSIONS Lingual bracket indirect bonding using double vacuum-formed trays fabricated on 3-dimensional printed models has high transfer accuracy in the mesiodistal, buccolingual, and occlusogingival dimensions and rotation. However, the transfer of tip and torque is less accurate.
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Affiliation(s)
- Nguyen Viet Anh
- Viet Anh Orthodontic Clinic, Hanoi, Vietnam; School of Dentistry, Hanoi Medical University, Hanoi, Vietnam.
| | - Nguyen Minh Duc
- Division of Research and Treatment for Oral Maxillofacial Congenital Anomalies, Aichi Gakuin University, Nagoya, Japan
| | - Nguyen Thu Tra
- School of Dentistry, Hanoi Medical University, Hanoi, Vietnam
| | | | - Tong Minh Son
- School of Dentistry, Hanoi Medical University, Hanoi, Vietnam
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Wang YG, Zhu GY, Liu JQ, Wang YF, Zhao ZH. Dynamic biomechanical changes of clear aligners during extraction space closure: Finite element analysis. Am J Orthod Dentofacial Orthop 2024; 165:272-284.e3. [PMID: 38108674 DOI: 10.1016/j.ajodo.2023.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 12/19/2023]
Abstract
INTRODUCTION Clear aligners (CAs) have recently become popular and widely used orthodontic appliances. Research on CA biomechanics has become a focal point in orthodontics to improve the efficiency of CA treatment and address challenging issues, such as extraction. The biomechanical characteristics of CAs in space closure have been reported. However, previous studies have mainly focused on static biomechanical analysis that cannot demonstrate the dynamic biomechanical changes in CAs during space-closing. Given that these biomechanical changes can be significant and have considerable clinical value, this study aimed to investigate these characteristics. METHODS Sequential extraction space-closing models were derived from included patient data and refined using modeling and CA design software. A finite element analysis was performed to obtain biomechanical raw data. This study introduced a dual coordinate system and space geometry analysis to demonstrate the biomechanical properties accurately. RESULTS As space closure progressed, the instantaneous tooth displacements increased, indicating an enhanced space closure force because of the increased strain in the CA extraction area. Meanwhile, the central axis of rotation of the anterior teeth continuously moved toward the labial-apical direction, showing a gradually enhanced vertical and torque control effect. CONCLUSIONS During space closure, CAs undergo specific biomechanical changes, including increased contraction and control forces on both sides of the gap. These biomechanical effects are beneficial to alleviate the roller coaster effect gradually. Meanwhile, more reasonable staging design strategies can be proposed on the basis of this biomechanical mechanism.
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Affiliation(s)
- Yi-Gan Wang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Guan-Yin Zhu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jun-Qi Liu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yi-Fan Wang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Zhi-He Zhao
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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Geramy A, Safari F. Effect of clear aligner type on maxillary full-arch intrusion: 3D analysis using finite element method. BMC Oral Health 2024; 24:231. [PMID: 38350943 PMCID: PMC10865575 DOI: 10.1186/s12903-024-03984-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 02/05/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Vertical maxillary excess (VME) is one of the most common reasons for seeking orthodontic treatment. Total intrusion with aligners is a promising alternative to surgery in some cases. Considering the elastic deformation of aligners, this study aimed to evaluate the possible desirable and undesirable teeth displacements during full maxillary arch intrusion using clear aligners and temporary anchorage devices (TADs). METHODS The maxillary arch and clear aligners were modeled in SolidWorks. Four aligner brands including Leon, Duran, Duran Plus, and Essix Plus were selected based on their material properties. Anterior and posterior intrusion forces of 80 and 300 g were applied from attachments between the canines and first premolars and between the first and second molars, respectively. Vertical and anteroposterior tooth displacements were determined. RESULTS The greatest intrusion was recorded at the buccal of the second molar, followed by the first molar. The lowest value was measured at the palatal of the molars with all aligners except Duran, which indicated minimal intrusion in the central incisor. All teeth were mesially displaced at the incisal/occlusal except incisors that moved distally. All apices showed distal movement. CONCLUSIONS Total intrusion using clear aligners may be accompanied by other tooth movements, including buccal tipping and mesial-in rotation of the molars, retrusion of incisors, and mesial movement of other teeth.
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Affiliation(s)
- Allahyar Geramy
- Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Safari
- Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
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Zhu L, Liu L, Wang W, Deng WW. Effects of different patterns of movement for correcting a deep curve of Spee with clear aligners on the anterior teeth: a finite element analysis. BMC Oral Health 2024; 24:217. [PMID: 38341537 PMCID: PMC10859030 DOI: 10.1186/s12903-024-03906-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/16/2024] [Indexed: 02/12/2024] Open
Abstract
OBJECTIVE To analyse the anterior teeth effects of clear aligners on five different patterns of mandibular molar movement and to define the most effective configuration to be implemented with clear aligners through finite element analysis. METHODS A three-dimensional mandibular model with a deep overbite in the mandible was constructed using cone beam computerized tomography (CBCT) data. The model included the mandibular dentition, mandibular periodontal ligaments, attachments, and aligners. Five models were created: (1) configuration A: second molar distalization (0.25 mm); (2) configuration B: second molar distalization (0.25 mm), first molar extrusion (0.15 mm); (3) configuration C: second molar distalization (0.25 mmm), first and second premolar extrusion(0.15 mm); (4) configuration D: second molar distalization (0.25 mm), first molar and first/second premolar extrusion(0.15 mm); and (5) configuration E: second molar distalization (0.25 mm), first molar and first/second premolar extrusion (0.15 mm), first molar and first/second premolar expansion (0.15 mm). RESULTS In all configurations, the anterior teeth exhibited labial tipping and the mandibular central incisor of configuration E showed the highest labial tipping. Configuration E demonstrated a relatively minor impact on mandibular molars distalization compared with configuration A. Configuration A showed the highest distal displacement value, and configuration E produced the lowest displacement value. Configuration E caused the highest periodontal ligament (PDL) pressure of the central and lateral incisors. The differences in the canines between configurations C and D,were not significant, and the stress distribution differed among the five groups. CONCLUSIONS All patterns utilizing clear aligners facilitated mandibular molar distalization. Extruding the premolars and second molar distalization at the same time had little impact on second molar distalization; When expansion and extrusion were simultaneously performed during the distalization of mandibular molars, our prime consideration was the alveolar bone on the labial side of the anterior teeth to prevent the occurrence of gingival recession, dehiscence, and fenestration. Due to the lack of consideration for periodontal tissues in this study, clinical protocols should be designed based on the periodontal status of the mandibular anterior teeth.
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Affiliation(s)
- Lin Zhu
- Graduate School of Dalian Medical University, Dalian, China
| | - Lin Liu
- Department of Orthodontics, DaLian Stomatological Hospital, DaLian, China.
| | - Wei Wang
- Urumql DW Innovation InfoTech Co., Ltd., Urumqi, Xinjiang, China
| | - Wen Wen Deng
- Department of Orthodontics, DaLian Stomatological Hospital, DaLian, China
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Khursheed Alam M, Hajeer MY, Shqaidef A, Alswairki HJ, Alfawzan AA, Shrivastava D, Chandan Srivastava K, Cicciù M, Minervini G. Impact of various aligner auxiliaries on orthodontic activity: A systematic review and network meta-analysis. Saudi Dent J 2024; 36:199-207. [PMID: 38419986 PMCID: PMC10897539 DOI: 10.1016/j.sdentj.2023.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/18/2023] [Accepted: 10/24/2023] [Indexed: 03/02/2024] Open
Abstract
Background It is imperative to analyze the forces and moments produced by various auxiliaries in order to select the optimal attachments and, eventually, to maximize the efficacy and efficiency of orthodontic therapy. Through this investigation, we aimed to highlight the impact of various aligner auxiliaries on orthodontic activity in patients undergoing orthodontic treatment on a pre/post treatment protocol basis. Methods After a thorough search of the online journals, a total of 482 documents were found using keywords such as "Orthodontic Treatment", "Aligner Auxiliaries", "Elastic Ligatures" and "Tooth Movement." The database research, elimination of duplicate studies, data extraction and risk of bias were performed by the authors independently. This systematic review and network meta-analysis included prospective studies and clinical trials to evaluate research that had looked at the impact of various aligner auxiliaries on orthodontic activity in patients undergoing orthodontic treatment. Results Eight investigations of varying designs were selected for this review. The majority of investigations revealed that aligner auxiliaries significantly improve anterior root torque, rotation, and mesio-distal (M-D) movement, as well as posterior anchoring. They also significantly improved anterior root rotation. However, few studies have presented inconsistent or non-statistically significant findings. Conclusion Auxiliaries for aligners also appear to improve extrusion and other orthodontic movements, but there is insufficient evidence to support these claims. No research has examined posterior bucco-lingual expansion or tilting. Clarification of the effect of attachments and their related variables requires additional clinical investigations.
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Affiliation(s)
- Mohammad Khursheed Alam
- Orthodontic Division, Preventive Dentistry Department, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
- Department of Dental Research Cell, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Chennai, India
- Department of Public Health, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, Bangladesh
| | - Mohammad Younis Hajeer
- Department of Orthodontics, University of Damascus Faculty of Dentistry, Damascus, Syria
| | - Abedalrahman Shqaidef
- Department of Clinical Sciences, Center of Medical and Bio-Allied Health Sciences Research, College of Dentistry, Ajman University, Ajman, United Arab Emirates
| | | | - Ahmed Ali Alfawzan
- Department of Preventive Dentistry, College of Dentistry in Ar Rass, Qassim University, Ar Rass 52571, Saudi Arabia
| | - Deepti Shrivastava
- Periodontics Division, Preventive Dentistry Department, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
| | - Kumar Chandan Srivastava
- Department of Oral & Maxillofacial Surgery & Diagnostic Sciences, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
- Department of Oral Medicine and Radiology, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai 602105, India
| | - Marco Cicciù
- Department of Biomedical and Surgical and Biomedical Sciences, Catania University, 95123 Catania, Italy
| | - Giuseppe Minervini
- Saveetha Dental College & Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai 600 077, India
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Campania, Luigi Vanvitelli, 80138 Naples, Italy
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Jin X, Tian X, Lee Zhi Hui V, Zheng Y, Song J, Han X. The effect of enhanced structure in the posterior segment of clear aligners during anterior retraction: a three-dimensional finite element and experimental model analysis. Prog Orthod 2024; 25:3. [PMID: 38221549 PMCID: PMC10788328 DOI: 10.1186/s40510-023-00502-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/21/2023] [Indexed: 01/16/2024] Open
Abstract
BACKGROUND Mesial tipping of posterior teeth occurs frequently during space closure with clear aligners (CAs). In this study, we proposed a new modification of CA by localized thickening of the aligner to form the enhanced structure and investigate its biomechanical effect during anterior retraction. METHODS Two methods were employed in this study. First, a finite element (FE) model was constructed, which included alveolar bone, the first premolars extracted maxillary dentition, periodontal ligaments (PDL), attachments and aligners. The second method involved an experimental model-a measuring device using multi-axis transducers and vacuum thermoforming aligners. Two groups were formed: (1) The control group used common CAs and (2) the enhanced structure group used partially thickened CAs. RESULTS FE model revealed that the enhanced structure improved the biomechanics during anterior retraction. Specifically, the second premolar, which had a smaller PDL area, experienced a smaller protraction force and moment, making it less likely to tip mesially. In the same vein, the molars could resist movement due to their larger PDL area even though they were applied larger forces. The resultant force of the posterior tooth was closer to the center of resistance, reducing the tipping moment. The canine was applied a larger retraction force and moment, resulting in sufficient retraction of anterior teeth. The experimental model demonstrated a similar trend in force variation as the FE model. CONCLUSIONS Enhanced structure allowed force distribution more in accordance with optimal principles of biomechanics during the extraction space closure while permitting less mesial tipping and anchorage loss of posterior teeth and better retraction of anterior teeth. Thus, enhanced structure alleviated the roller coaster effect associated with extraction cases and offered a new possibility for anchorage reinforcement in clear aligner therapy.
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Affiliation(s)
- Xiaohan Jin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, 14# 3Rd Section of Ren Min Nan Road, Chengdu, 610041, Sichuan Province, China
| | - Xue Tian
- Jiangmen Municipal Stomatology Hospital, Yongli Street, Shengli Road, Jiangmen, 529000, Guangdong Province, China
| | - Victoria Lee Zhi Hui
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, 14# 3Rd Section of Ren Min Nan Road, Chengdu, 610041, Sichuan Province, China
| | - Yikan Zheng
- R&D Center, EA Medical Center Device Technologies Co., Ltd, Middle Branch Road, Wuxi, 214174, Jiangsu Province, China
| | - Jinlin Song
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Stomatological Hospital of Chongqing Medical University, Chongqing Medical University, 426# Songshibei Road, Chongqing, China
| | - Xianglong Han
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, 14# 3Rd Section of Ren Min Nan Road, Chengdu, 610041, Sichuan Province, China.
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Danko M, Chromy L, Ferencik N, Sestakova M, Kolembusova P, Balint T, Durica J, Zivcak J. Literature Review of an Anterior Deprogrammer to Determine the Centric Relation and Presentation of Cases. Bioengineering (Basel) 2023; 10:1379. [PMID: 38135970 PMCID: PMC10740564 DOI: 10.3390/bioengineering10121379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
The increasing demand for dental aesthetics, articulation corrections, and solutions for pain and frequent bruxism demands quick and effective restorative dental management. The biomedical research aimed to create a beneficial, ecological, and readily available anterior deprogrammer to determine the centric relation (CR) of cases. This medical device is additively manufactured from a biocompatible material. Size is customizable based on the width of the patient's anterior central incisors. This is a pilot study with two subjects. The task was to develop a complete data protocol for the production process, computer-aided design (CAD), and three-dimensional (3D) printing of the anterior deprogrammers. The research focused on creating simple and practically applicable tools for the dentist's prescription (anterior deprogrammer in three sizes), and secondly for the communication between the dentist and the patient (computer application). The tested hypothesis was whether, according to these novel tools, it is possible to produce functional occlusal splints, which could be manufactured using current technologies. This study compared a traditional splint with a digitally designed and 3D-printed one. The tested hypothesis was whether manufactured occlusal splints differ in patients' subjective perception of comfort. Each conservative treatment was monitored for ten weeks. Initial results are promising; no statistically significant difference was found between the productive technologies.
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Affiliation(s)
- Maria Danko
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
| | - Lubos Chromy
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
| | - Norbert Ferencik
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
| | - Marcela Sestakova
- 1st Department of Stomatology, Faculty of Medicine, Pavol Jozef Safarik University in Kosice, 04154 Kosice, Slovakia; (M.S.); (J.D.)
| | - Petra Kolembusova
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
| | - Tomas Balint
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
| | - Jaroslav Durica
- 1st Department of Stomatology, Faculty of Medicine, Pavol Jozef Safarik University in Kosice, 04154 Kosice, Slovakia; (M.S.); (J.D.)
| | - Jozef Zivcak
- Department of Biomedical Engineering and Measurement, Faculty of Mechanical Engineering, Technical University of Kosice, 04200 Kosice, Slovakia; (L.C.); (N.F.); (P.K.); (T.B.); (J.Z.)
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14
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Inan A, Gonca M. Effects of aligner activation and power arm length and material on canine displacement and periodontal ligament stress: a finite element analysis. Prog Orthod 2023; 24:40. [PMID: 38008884 PMCID: PMC10678869 DOI: 10.1186/s40510-023-00492-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/16/2023] [Indexed: 11/28/2023] Open
Abstract
BACKGROUND This study aimed to assess the impact of aligner activation and power arm length and material on canine and aligner displacement, von Mises stress in the power arm, and principal stress in the periodontal ligament (PDL) during canine tooth distalization using finite element analysis (FEA). The effects of aligner activation and power arm length were primary outcomes, while the effect of the power arm material was a secondary outcome. METHODS Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis. RESULTS Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm. CONCLUSION Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.
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Affiliation(s)
| | - Merve Gonca
- Department of Orthodontics, Faculty of Dentistry, Recep Tayyip Erdoğan University, Rize, Turkey.
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Oh S, Choi YK, Kim SH, Ko CC, Kim KB, Kim YI. Biomechanical analysis for different mandibular total distalization methods with clear aligners: A finite element study. Korean J Orthod 2023; 53:420-430. [PMID: 37989578 PMCID: PMC10663580 DOI: 10.4041/kjod23.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 11/23/2023] Open
Abstract
Objective : The purpose of this finite element method (FEM) study was to analyze the biomechanical differences and tooth displacement patterns according to the traction direction, methods, and sites for total distalization of the mandibular dentition using clear aligner treatment (CAT). Methods : A finite element analysis was performed on four FEM models using different traction methods (via a precision cut hook or button) and traction sites (mandibular canine or first premolar). A distalization force of 1.5 N was applied to the traction site by changing the direction from -30 to +30° to the occlusal plane. The initial tooth displacement and von Mises stress on the clear aligners were analyzed. Results : All CAT-based total distalization groups showed an overall trend of clockwise or counterclockwise rotation of the occlusal plane as the force direction varied. Mesiodistal tipping of individual teeth was more prominent than that of bodily movements. The initial displacement pattern of the mandibular teeth was more predominant based on the traction site than on the traction method. The elastic deformation of clear aligners is attributed to unintentional lingual tipping or extrusion of the mandibular anterior teeth. Conclusions : The initial tooth displacement can vary according to different distalization strategies for CAT-based total distalization. Discreet application and biomechanical understanding of traction sites and directions are necessary for appropriate mandibular total distalization.
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Affiliation(s)
- Sewoong Oh
- Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea
| | - Youn-Kyung Choi
- Department of Orthodontics, Pusan National University Hospital, Busan, Korea
| | - Sung-Hun Kim
- Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea
| | - Ching-Chang Ko
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Ki Beom Kim
- Department of Orthodontics, Saint Louis University, Saint Louis, Mo, USA
| | - Yong-Il Kim
- Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, Korea
- Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Korea
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Kang F, Wu Y, Cui Y, Yuan J, Hu Z, Zhu X. The displacement of teeth and stress distribution on periodontal ligament under different upper incisors proclination with clear aligner in cases of extraction: a finite element study. Prog Orthod 2023; 24:38. [PMID: 37981597 PMCID: PMC10657915 DOI: 10.1186/s40510-023-00491-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/08/2023] [Indexed: 11/21/2023] Open
Abstract
OBJECTIVES To investigate the displacement of dentition and stress distribution on periodontal ligament (PDL) during retraction and intrusion of anterior teeth under different proclination of incisors using clear aligner (CA) in cases involving extraction of the first premolars. METHODS Models were constructed, consisting of the maxilla, PDLs, CA and maxillary dentition without first premolars. These models were then imported to finite element analysis (FEA) software. The incisor proclination determined the division of the models into three groups: Small torque (ST) with U1-SN = 100°, Middle torque (MT) with U1-SN = 110°, and High torque (HT) with U1-SN = 120°. Following space closure, a 200 g intrusion force was applied at angles of 60°, 70°, 80°, and 90° to the occlusal plane, respectively. RESULTS CA therapy caused lingual tipping and extrusion of incisors, mesial tipping and intrusion of canines, and mesial tipping of posterior teeth in each group. As the proclination of incisors increased, the incisors presented more extrusion and minor retraction, and the teeth from the canine to the second molar displayed an increased tendency of intrusion. The peak Von Mises equivalent stress (VMES) value successively decreased from the central incisor to the canine and from the second premolar to the second molar, and the VMES of the second molar was the lowest among the three groups. When the angle between the intrusion force and occlusal plane got larger, the incisors exhibited greater intrusion but minor retraction. CONCLUSIONS The "roller coaster effect" usually occurred in cases involving premolar extraction with CA, especially in patients with protruded incisors. The force closer to the vertical direction were more effective in achieving incisor intrusion. The stress on PDLs mainly concentrated on the cervix and apex of incisors during the retraction process, indicating a possibility of root resorption.
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Affiliation(s)
- Fujia Kang
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China
| | - Yumiao Wu
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China
| | - Yuchen Cui
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China
| | - Jiamin Yuan
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China
| | - Zhiqiang Hu
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China
| | - Xianchun Zhu
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Jilin University, Changchun, Jilin, China.
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Li N, Wang CJ, Wang Y, Chen D, Yang M, Li H. Three-dimensional finite element analysis of retracting pathological migration of the right upper central incisor with a clear aligner. Comput Methods Biomech Biomed Engin 2023:1-8. [PMID: 37936535 DOI: 10.1080/10255842.2023.2279011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 10/23/2023] [Indexed: 11/09/2023]
Abstract
We aimed to explore the best orthodontic step distance of the right upper central incisor with mild, moderate, and severe pathological displacement achieved via a clear aligner. Three-dimensional models of maxilla-tooth-periodontal ligament clear aligner of the right upper central incisors with five different steps of 0.1, 0.125, 0.15, 0.165, 0.25 mm and three different alveolar bone heights were established via finite element analysis. We analysed the changing trends in initial displacement, the periodontal ligament, the alveolar bone, and apical stress of right upper central incisor. In the process of retraction, the right upper central incisor a movement trend of the crown deviating from the distal root to the mesial, and with the decrease of the height of the alveolar bone and the increase of the displacement, the crown would appear distal labial torsion with a deepening trend of vertical overlay.The maximum stress distribution of the periodontal ligament and alveolar bone showed a positive correlation. The overall stress distribution of the periodontal ligament and apical stress increased with decrease of alveolar bone height and the increase of alveolar bone displacement. In patients with mild, moderate, and severe pathological displacement of the right upper central incisor, the best step distance of anterior tooth retraction is 0.165, 0.15, and 0.125 mm, respectively.
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Affiliation(s)
- Na Li
- Silk Crossing Clinic, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - Chun Juan Wang
- Chongqing Key Laboratory of Oral Diseases and Biomedicine, Chongqing Municipal Key Laboratory of Stomatological Biomedical Engineering, Chongqing, China
| | - Yu Wang
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - DingGen Chen
- Silk Crossing Clinic, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - Min Yang
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
| | - HuiQin Li
- Department of Stomatology, North Sichuan Medical College, Nanchong, China
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Wang S, Huang Y, Fan D, Liu H, Yuan C, Yang L, Wang P. Effects of overtreatment with different attachment positions on maxillary anchorage enhancement with clear aligners: a finite element analysis study. BMC Oral Health 2023; 23:693. [PMID: 37749548 PMCID: PMC10521390 DOI: 10.1186/s12903-023-03340-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/22/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND The effect of attachment positions on anchorage has not been fully explored. The aim of the present study is to analyze the effect of overtreatment with different anchorage positions on maxillary anchorage enhancement with clear aligners in extraction cases. METHODS Models of the maxilla and maxillary dentition were constructed and imported into SOLIDWORKS software to create periodontal ligament (PDL), clear aligners, and attachments. Attachment positions on second premolars included: without attachment (WOA), buccal attachment (BA), and bucco-palatal attachment (BPA). Overtreatment degrees were divided into five groups (0°, 1°, 2°, 3°, 4°) and added on the second premolars. The calculation and analysis of the displacement trends and stress were performed using ANSYS software. RESULTS Distal tipping and extrusion of the canines, and mesial tipping and intrusion of the posterior teeth occurred during retraction. A strong anchorage was achieved in cases of overtreatment of 2.8° with BA and 2.4° with BPA. Moreover, the BPA showed the best in achieving bodily control of the second premolars. When the overtreatment was performed, the canines and first molars also showed reduced tipping trends with second premolars attachments. And the stress on the PDL and the alveolar bone was significantly relieved and more evenly distributed in the BPA group. CONCLUSIONS Overtreatment is an effective means for anchorage enhancement. However, the biomechanical effect of overtreatment differs across attachment positions. The BPA design performs at its best for stronger overtreatment effects with fewer adverse effects.
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Affiliation(s)
- Shiyu Wang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Yangyang Huang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Dian Fan
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
| | - Hao Liu
- Department of Orthodontics, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Changyong Yuan
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China
- Department of Implantology, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Li Yang
- Department of Orthodontics, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China
| | - Penglai Wang
- School of stomatology, Xuzhou Medical University, 221000, Xuzhou, China.
- Department of Implantology, Affiliated Stomatological Hospital of Xuzhou Medical University, 221000, Xuzhou, China.
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AlMogbel A. Clear Aligner Therapy: Up to date review article. J Orthod Sci 2023; 12:37. [PMID: 37881665 PMCID: PMC10597356 DOI: 10.4103/jos.jos_30_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/11/2023] [Accepted: 05/02/2023] [Indexed: 10/27/2023] Open
Abstract
The advantages of Clear Aligners Therapy (CAT) include the braces being virtually invisible, comfortable to wear, and removable for eating and brushing; that way, CAT can be used to treat a wide range of orthodontic issues. In 1999, the company Align Technology introduced the frst commercial clear aligner system called Invisalign. The Invisalign system was initially only available to orthodontists, but later became available to general dentists as well. The system quickly gained popularity among patients who were looking for a more discreet and comfortable alternative to traditional braces. In 2000, Align Technology received FDA clearance for the Invisalign system, which further increased its popularity. The biomechanics of clear aligners involve the use of custom-made tooth aligners that are specifcally shaped to guide teeth into desired positions. These aligners are typically made from flexible materials such as polyurethane or ethylene vinyl acetate and are adjusted to apply the necessary forces for tooth movement. Attachment devices, such as power ridges or buttons, are often used to enhance or assist in specifc tooth movements and for retention of the aligner. The use of attachments allows for the exertion of desired force on the teeth, which is crucial for the success of Clear Aligner Therapy. CAT should be used if patients are concerned about the esthetic appearances of their teeth-for example, actors and other individuals that rely on their appearances in public in a professional context-and if the misalignment is not severe, so that clear aligners can still work. One should not use CAT in cases of severe crowding or spacing issues that require extractions. If the patient has complex jaw discrepancies or skeletal issues or if teeth need to be moved extensively in multiple directions, CAT is likely not going to be strong enough. In conclusion, Clear Aligner Therapy is a safe, effective, and convenient orthodontic treatment option that offers patients a virtually invisible way to achieve a straighter, more beautiful smile. With continued advancements in technology and a growing body of research supporting its effectiveness, the future of Clear Aligner Therapy looks bright.
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Affiliation(s)
- AbdulMajeed AlMogbel
- Department of Orthodontics and Pediatric Dentistry, College of Dentistry, Qassim University, Buraydah 52571, Saudi Arabia
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Kawamura J, Ojima K, Nanda R. Effect of attachment type on distal bodily movement of the maxillary canine in aligner orthodontics: a finite element study. Angle Orthod 2023; 93:566-571. [PMID: 37079796 PMCID: PMC10575637 DOI: 10.2319/120121-879.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/01/2023] [Indexed: 04/22/2023] Open
Abstract
OBJECTIVES To clarify the effect of attachment types on bodily movement of the maxillary canine in aligner orthodontics. MATERIALS AND METHODS Using an aligner, the canine was moved bodily by 0.1 mm distally as a target position. Orthodontic tooth movement was simulated using the finite element method (FEM). The alveolar socket was displaced in the same manner as the initial movement caused by elastic deformation of the periodontal ligament. First, the initial movement was calculated, and then the alveolar socket was displaced in the same direction and with the same magnitude as the initial movement. These calculations were repeated to move the teeth after placement of the aligner. The teeth and the alveolar bone were assumed to be rigid bodies. A FEM model of the aligner was made based on the crown surfaces. The thickness of the aligner was 0.45 mm, and its Young's modulus was 2 GPa. Three types of attachments-semicircular couple, vertical rectangular, and horizontal rectangular-were placed on the canine crown. RESULTS Regardless of the type of attachment, upon placement of the aligner on the dentition the crown of the canine moved to the target position, while the apex hardly moved. That is, the canine tipped and rotated. After repeating the calculation, the canine became upright and moved bodily regardless of the attachment type. In the aligner without an attachment, the canine did not become upright. CONCLUSIONS There was almost no difference among attachment types in terms of achieving bodily movement of the canine.
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Affiliation(s)
- Jun Kawamura
- Corresponding author: Jun Kawamura, DDS, PhD, Kawamura Dental Office, 4-21 Sodensakae-machi Gifu City, Gifu, 502-0847, Japan (e-mail: )
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Meng X, Wang C, Xu W, Wang R, Zheng L, Wang C, Aversa R, Fan Y. Effects of different designs of orthodontic clear aligners on the maxillary central incisors in the tooth extraction cases: a biomechanical study. BMC Oral Health 2023; 23:416. [PMID: 37349701 PMCID: PMC10288704 DOI: 10.1186/s12903-023-03106-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 06/05/2023] [Indexed: 06/24/2023] Open
Abstract
BACKGROUND Controlling the 3D movement of central incisors during tooth extraction cases with clear aligners is important but challenging in invisible orthodontic treatment. This study aimed to explore the biomechanical effects of central incisors in tooth extraction cases with clear aligners under different power ridge design schemes and propose appropriate advice for orthodontic clinic. METHODS A series of Finite Element models was constructed to simulate anterior teeth retraction or no retraction with different power ridge designs. These models all consisted of maxillary dentition with extracted first premolars, alveolar bone, periodontal ligaments and clear aligner. And the biomechanical effects were analysed and compared in each model. RESULTS For the model of anterior teeth retraction without power ridge and for the model of anterior teeth no retraction with a single power ridge, the central incisors exhibited crown lingual inclination and relative extrusion. For the model of anterior teeth no retraction with double power ridges, the central incisors tended to have crown labial inclination and relative intrusion. For the model of anterior tooth retraction with double power ridges, the central incisors exhibited a similar trend to the first kind of model, but as the depth of the power ridge increased, there was a gradual decrease in crown retraction value and an increase in crown extrusion value. The simulated results showed that von-Mises stress concentration was observed in the cervical and apical regions of the periodontal ligaments of the central incisors. The clear aligner connection areas of adjacent teeth and power ridge areas also exhibited von-Mises stress concentration and the addition of power ridge caused the clear aligner to spread out on the labial and lingual sides. CONCLUSIONS The central incisors are prone to losing torque and extruding in tooth extraction cases. Double power ridges have a certain root torque effect when there are no auxiliary designs, but they still cannot rescue tooth inclination during tooth retraction period. For tooth translation, it may be a better clinical procedure to change the one-step aligner design to two-step process: tilting retraction and root control.
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Affiliation(s)
- Xuehuan Meng
- Stomatological Hospital of Chongqing Medical University, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
| | - Chunjuan Wang
- Stomatological Hospital of Chongqing Medical University, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
| | - Wenjie Xu
- Stomatological Hospital of Chongqing Medical University, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
| | - Rui Wang
- Stomatological Hospital of Chongqing Medical University, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China
| | - Leilei Zheng
- Stomatological Hospital of Chongqing Medical University, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China.
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China.
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, No.426 Songshibei Road, Yubei District, Chongqing, 401147, China.
| | - Chao Wang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, No.37, Xueyuan Road, Beijing, 100083, China.
| | - Raffaella Aversa
- Advanced Material Lab, University of Campania, Luigi Vanvitelli, Caserta, Italy
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, No.37, Xueyuan Road, Beijing, 100083, China
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22
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Yao S, Jiang W, Wang C, He Y, Wang C, Huang L. Improvements of tooth movement efficiency and torque control in expanding the arch with clear aligners: a finite element analysis. Front Bioeng Biotechnol 2023; 11:1120535. [PMID: 37324442 PMCID: PMC10267454 DOI: 10.3389/fbioe.2023.1120535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 05/25/2023] [Indexed: 06/17/2023] Open
Abstract
Objectives: The purpose of this study was to analyze the effect of different movement strategies, embossment structures, and torque compensation of the aligner on tooth movement during arch expansion using clear aligners by finite element analysis. Methods: Models comprising the maxilla, dentition, periodontal ligament, and aligners were created and imported into a finite element analysis software. The tests were performed using the following: three orders of tooth movement (including alternating movement with the first premolar and first molar, whole movement with second premolar and first molar or premolars and first molar), four different shapes of embossment structures (ball, double ball, cuboid, cylinder, with 0.05, 0.1, 0.15-mm interference) and torque compensation (0°, 1°, 2°, 3°, 4°, and 5°). Results: The expansion of clear aligners caused the target tooth to move obliquely. Alternating movement resulted in higher movement efficiency with lower anchorage loss as compared with whole movement. Embossment increased the efficiency of crown movement but did not contribute positively to torque control. As the angle of compensation increased, the tendency of oblique tooth movement was gradually controlled; however, the movement efficiency decreased concurrently, and stress distribution on the periodontal ligament became more even. For each 1° increase in compensation, the torque per millimeter of the first premolar would decrease by 0.26°/mm, and the crown movement efficiency eliminate decreased by 4.32%. Conclusion: Alternating movement increases the efficiency of the arch expansion by the aligner and reduces anchorage loss. Torque compensation should be designed to enhance torque control in arch expansion using an aligner.
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Affiliation(s)
- Song Yao
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Wei Jiang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Chunjuan Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Yao He
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Chao Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Lan Huang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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23
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Sawamura M, Nakano H, Shiogama M, Takano N, Maki K. Using digital image correlation to measure displacement and strain during involving distal movement of anterior teeth with clear aligner. Dent Mater J 2023. [PMID: 37121736 DOI: 10.4012/dmj.2022-255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
To investigate methods to suppress the bowing effects of lingual inclination and anterior tooth extrusion, digital image correlation (DIC) was used to evaluate aligner displacement in three-dimensions through comparing the distal movement of six and four anterior teeth. Computed tomography scans were used to measure aligner thickness and shape. Based on displacement direction and magnitude, a desirable deformation mode with minimal lingual inclination and extrusion was observed during distal movement of four anterior teeth. The aligner had a rigid "constriction zone" between the lateral incisor and the canine, facilitating control localized to the anterior teeth and minimizing the reaction of the molars. The mechanical behavior of aligners was greatly affected by the method of anterior teeth movement and the shape of aligners. DIC-based displacement measurements are useful in investigating correction directionality.
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Affiliation(s)
- Moeka Sawamura
- Department of Orthodontics, School of Dentistry, Showa University
| | - Haruhisa Nakano
- Department of Orthodontics, School of Dentistry, Showa University
| | - Motoya Shiogama
- Department of Orthodontics, School of Dentistry, Showa University
| | - Naoki Takano
- Department of Mechanical Engineering, Keio University
| | - Kotaro Maki
- Department of Orthodontics, School of Dentistry, Showa University
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24
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Yang Y, Yang R, Liu L, Zhang X, Jiang Q, Fan Q, Zhang H, Long H, Lai W. The effects of aligner anchorage preparation on mandibular first molars during premolar-extraction space closure with clear aligners: A finite element study. Am J Orthod Dentofacial Orthop 2023:S0889-5406(23)00098-7. [PMID: 37024337 DOI: 10.1016/j.ajodo.2022.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 04/08/2023]
Abstract
INTRODUCTION This study aimed to determine the effectiveness of different aligner anchorage preparations on mandibular first molars during premolar-extraction space closure with clear aligners and to assess the effects of different modes of Class II elastics on mandibular first molars. METHODS Finite element models were constructed on the basis of cone-beam computed tomography data from an orthodontic patient. The models comprised maxilla, mandible, maxillary and mandibular teeth without first premolars, periodontal ligaments, attachments and aligners. Tooth displacement tendencies were calculated using different aligner anchorage preparations and Class II elastics on the models from the same patient. Three group sets were designed on the basis of the positions of aligner cutouts and buttons (mesiobuccal, distobuccal and lingual). Four groups were established in each of the 3 group sets. Four groups were created: (1) no elastic traction + no anchorage preparation, (2) anchorage preparation only, (3) elastic traction only, and (4) elastic traction + anchorage preparation. Different aligner anchorage preparations (0°, 1°, 2°, 3°) were applied on mandibular second premolars and molars. The Class II traction force was set to 100 g. RESULTS With clear aligners, mandibular first molars were subject to mesial tipping, lingual tipping and intrusion. In the condition of no elastic traction, aligner anchorage preparation resulted in distal tipping, buccal tipping, and extrusion effect on mandibular first molars. Aligner anchorage preparation was more effective in the distal and lingual cutout groups than in the mesial cutout group. In the condition of Class II elastic traction, the bodily movement of mandibular first molars was achieved with a 3° anchorage preparation for the mesial cutout group and a 1.7° anchorage preparation for distal and lingual cutout groups. Absolute maximal anchorage was achieved with a 2° anchorage preparation for distal and lingual cutout groups. CONCLUSIONS Clear aligner therapy caused mesial tipping, lingual tipping and intrusion of mandibular first molars during premolar-extraction space closure. Aligner anchorage preparation effectively prevented mesial and lingual tipping of mandibular molars. Distal and lingual cutout modes were more effective than mesial cutout modes in aligner anchorage preparation. For each aligner stage (0.25 mm), 1.7° aligner anchorage preparation and Class II elastics with distal or lingual cutouts led to the bodily movement of mandibular first molars, whereas 2° anchorage preparation reached absolute maximal anchorage.
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Affiliation(s)
- Yi Yang
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ruicong Yang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China
| | - Lu Liu
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xiaoqi Zhang
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qingsong Jiang
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qi Fan
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Haoxin Zhang
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Hu Long
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
| | - Wenli Lai
- Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Center for Oral Research, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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25
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Liu JQ, Zhu GY, Wang YG, Zhang B, Yao K, Zhao ZH. Different biomechanical effects of clear aligners in closing maxillary and mandibular extraction spaces: Finite element analysis. Am J Orthod Dentofacial Orthop 2023; 163:811-824.e2. [PMID: 36964108 DOI: 10.1016/j.ajodo.2022.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 03/26/2023]
Abstract
INTRODUCTION Compared with fixed treatments, clear aligners (CAs) have the advantages of comfort, esthetics, and hygiene, and are popular among patients and orthodontists. However, CAs exhibit control deficiencies in extraction patients because of insufficient root control and retention effects. These deficiencies can magnify biomechanical differences in bimaxillary dentition, further causing different orthodontic requirements between maxillary and mandibular dentition. This study aimed to elaborate on the biomechanical characteristics of bimaxillary dentition in extraction space closure and provided feasible biomechanical compensation strategies for use in clinical practice. METHODS We constructed a 3-dimensional (3D) bimaxillary model based on patient data. Several 3D modeling-related software was used to generate a standard first premolar extraction model, CAs, and attachments. Subsequently, finite element analysis was performed to demonstrate the biomechanical effects. RESULTS The maxillary and mandibular dentition showed a roller coaster effect during space closure. Compared with the maxillary dentition, the mandibular posterior teeth exhibited stronger relative anchorage causing greater anterior teeth retraction. The tipping and vertical movements of the anterior teeth were related to tooth length. The longer the anterior tooth, the less tipping and greater vertical displacement occurred. Generally, when having the same retraction distance, the mandibular dentition exhibited greater retroclination and fewer extrusions. Both mechanical and retention compensations should be considered to prevent these unwanted tipping movements. Adding specific attachments to bimaxillary dentitions compensated for the retention and root control deficiencies of CAs. CONCLUSIONS When applying CAs to extraction patients, different biomechanical effects can present in the bimaxillary dentition because of specific dentition morphologies. To effectively treat these patients, mechanical compensation through overcorrection of the target position should be designed on the basis of bimaxillary control deficiencies, and retention compensation by adding specific attachments should also be considered according to the overcorrections.
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Affiliation(s)
- Jun-Qi Liu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Guan-Yin Zhu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yi-Gan Wang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Bo Zhang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ke Yao
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Zhi-He Zhao
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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26
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Jedliński M, Mazur M, Greco M, Belfus J, Grocholewicz K, Janiszewska-Olszowska J. Attachments for the Orthodontic Aligner Treatment-State of the Art-A Comprehensive Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4481. [PMID: 36901488 PMCID: PMC10001497 DOI: 10.3390/ijerph20054481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND In recent years the burden of aligner treatment has been growing. However, the sole use of aligners is characterized by limitations; thus attachments are bonded to the teeth to improve aligner retention and tooth movement. Nevertheless, it is often still a challenge to clinically achieve the planned movement. Thus, the aim of this study is to discuss the evidence of the shape, placement and bonding of composite attachments. METHODS A query was carried out in six databases on 10 December 2022 using the search string ("orthodontics" OR "malocclusion" OR "Tooth movement techniques AND ("aligner*" OR "thermoformed splints" OR "invisible splint*" AND ("attachment*" OR "accessor*" OR "auxill*" AND "position*"). RESULTS There were 209 potential articles identified. Finally, twenty-six articles were included. Four referred to attachment bonding, and twenty-two comprised the influence of composite attachment on movement efficacy. Quality assessment tools were used according to the study type. CONCLUSIONS The use of attachments significantly improves the expression of orthodontic movement and aligner retention. It is possible to indicate sites on the teeth where attachments have a better effect on tooth movement and to assess which attachments facilitate movement. The research received no external funding. The PROSPERO database number is CRD42022383276.
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Affiliation(s)
- Maciej Jedliński
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
- Department of Dental and Maxillofacial Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Marta Mazur
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
- Department of Dental and Maxillofacial Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Mario Greco
- Department of Paediatric Dentistry, University of L’Aquila, 67100 L’Aquila, Italy
| | - Joyce Belfus
- Faculty of Dentistry, Universidad de los Andes, Santiago 7620001, Chile
| | - Katarzyna Grocholewicz
- Department of Interdisciplinary Dentistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
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Ahmad W, Jiang F, Xiong J, Xia Z. The mechanical effect of geometric design of attachments in invisible orthodontics. Am J Orthod Dentofacial Orthop 2023:S0889-5406(23)00075-6. [PMID: 36990956 DOI: 10.1016/j.ajodo.2022.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/01/2022] [Accepted: 11/01/2022] [Indexed: 03/29/2023]
Abstract
INTRODUCTION In invisible orthodontics, attachments are used with aligners to better control tooth movement. However, to what extent the geometry of the attachment can affect the biomechanical properties of the aligner is unknown. This study aimed to determine the biomechanical effect of attachment geometry on orthodontic force and moment using 3-dimensional finite element analysis. METHODS A 3-dimensional model of mandibular teeth, periodontal ligaments, and the bone complex was employed. Rectangular attachments with systematic size variations were applied to the model with corresponding aligners. Fifteen pairs were created to move the lateral incisor, canine, first premolar, and second molar mesially for 0.15 mm, respectively. The resulting orthodontic forces and moments were analyzed to compare the effect of attachment size. RESULTS Expansion in the attachment size showed a continuous increase in force and moment. Considering the attachment size, the moment increased more than the force, resulting in a slightly higher moment-to-force ratio. Expanding the length, width, or thickness of the rectangular attachment by 0.50 mm increases the force and moment up to 23 cN and 244 cN-mm, respectively. The force direction was closer to the desired movement direction with larger attachment sizes. CONCLUSIONS Based on the experimental results, the constructed model successfully simulates the effect of the size of attachments. The larger the size of the attachment, the greater the force and moment, and the better the force direction. The appropriate force and moment for a particular clinical patient can be obtained by choosing the right attachment size.
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Zhu GY, Zhang B, Yao K, Lu WX, Peng JJ, Shen Y, Zhao ZH. Finite element analysis of the biomechanical effect of clear aligners in extraction space closure under different anchorage controls. Am J Orthod Dentofacial Orthop 2023; 163:628-644.e11. [PMID: 36801091 DOI: 10.1016/j.ajodo.2022.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 02/17/2023]
Abstract
INTRODUCTION Clear aligners (CAs) have attracted increasing attention from patients and orthodontists because of their excellent esthetics and comfort. However, treating tooth extraction patients with CAs is difficult because their biomechanical effects are more complicated than those of traditional appliances. This study aimed to analyze the biomechanical effect of CAs in extraction space closure under different anchorage controls, including moderate, direct strong, and indirect strong anchorage. It could provide several new cognitions for anchorage control with CAs through finite element analysis, further directing clinical practice. METHODS A 3-dimensional maxillary model was generated by combining cone-beam computed tomography and intraoral scan data. Three-dimensional modeling software was used to construct a standard first premolar extraction model, temporary anchorage devices, and CAs. Subsequently, finite element analysis was performed to simulate space closure under different anchorage controls. RESULTS Direct strong anchorage was beneficial for reducing the clockwise occlusal plane rotation, whereas indirect anchorage was conducive for anterior teeth inclination control. In the direct strong anchorage group, an increase in the retraction force would require more specific anterior teeth overcorrection to resist the tipping movement, mainly including lingual root control of the central incisor, followed by distal root control of the canine, lingual root control of the lateral incisor, distal root control of the lateral incisor, and distal root control of the central incisor. However, the retraction force could not eliminate the mesial movement of the posterior teeth, possibly causing a reciprocating motion during treatment. In indirect strong groups, when the button was close to the center of the crown, the second premolar presented less mesial and buccal tipping but more intrusion. CONCLUSIONS The 3 anchorage groups showed significantly different biomechanical effects in both the anterior and posterior teeth. Specific overcorrection or compensation forces should be considered when using different anchorage types. The moderate and indirect strong anchorages have a more stable and single-force system and could be reliable models in investigating the precise control of future tooth extraction patients.
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Affiliation(s)
- Guan-Yin Zhu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Bo Zhang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ke Yao
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wen-Xin Lu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jia-Jia Peng
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yu Shen
- School of Basic Medical Sciences, Chengdu University, Chengdu, China
| | - Zhi-He Zhao
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, and Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
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29
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Li Y, Xiao S, Jin Y, Zhu C, Li R, Zheng Y, Chen R, Xia L, Fang B. Stress and movement trend of lower incisors with different IMPA intruded by clear aligner: a three-dimensional finite element analysis. Prog Orthod 2023; 24:5. [PMID: 36775824 PMCID: PMC9922685 DOI: 10.1186/s40510-023-00454-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/02/2023] [Indexed: 02/14/2023] Open
Abstract
BACKGROUND During the intrusion of lower incisors with clear aligners (CAs), root disengagement from the alveolar bone often occurs, resulting in serious complications. This study aimed to determine the potential force mechanism of the mandibular anterior teeth under the pressure of CA, providing theoretical data for clinical practice. METHODS In this study, a 3D finite element model was established, including the CA, periodontal ligament, and mandibular dentition. Incisor mandibular plane angles were set as 5 groups: 90°, 95°, 100°, 105°, and 110°. The 4 mandibular incisors were intruded by 0.2 mm, while the canines were the anchorage teeth. The stress, force systems, and potential movement trends of mandibular anterior teeth were obtained. RESULTS The compressive stress of the incisors was concentrated in the lingual fossa, incisal ridge, and apex. With the increase in IMPA, the moment of central incisors changed from lingual crown moment to labial crown moment, with the turning point between 100° and 105°, but the center of resistance (CR) was always subjected to the force toward the lingual and intrusive direction. The force and moment toward the labial side of the lateral incisors were greater than those toward the central incisors. The canines always tipped distally and received extrusive force with no relationship with IMPA. CONCLUSIONS With the increase in the initial IMPA, the direction of labiolingual force on the mandibular incisors was reversed. However, the root of the lower incisors always tipped labially, which indicated fenestration and dehiscence.
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Affiliation(s)
- Yixin Li
- grid.16821.3c0000 0004 0368 8293Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011 China
| | - Shengzhao Xiao
- grid.16821.3c0000 0004 0368 8293Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011 China
| | - Yu Jin
- grid.16821.3c0000 0004 0368 8293Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011 China
| | - Cheng Zhu
- grid.16821.3c0000 0004 0368 8293Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011 China
| | - Ruomei Li
- grid.16821.3c0000 0004 0368 8293Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011 China
| | - Yikan Zheng
- grid.16821.3c0000 0004 0368 8293Translational Medicine Research Platform of Oral Biomechanics and Artificial Intelligence, Department of Orthodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai, 200011 China
| | - Rongjing Chen
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011, China.
| | - Lunguo Xia
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011, China.
| | - Bing Fang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine;College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, 500 Quxi Road, Shanghai, 200011, China.
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Kwak KH, Oh S, Choi YK, Kim SH, Kim SS, Park SB, Kim YI. Effects of different distalization directions and methods on maxillary total distalization with clear aligners: a finite element study. Angle Orthod 2023; 93:490510. [PMID: 36719258 PMCID: PMC10117206 DOI: 10.2319/072622-519.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 12/01/2022] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES To analyze the effects of maxillary tooth distalization by clear aligner (CA) treatment with variations in the angular direction of the distalization force, presence of attachments, and force-application method used. MATERIALS AND METHODS A finite element model containing alveolar bone, dentition, and periodontal ligament was constructed. Analytical model groups were as follows: (1) distalization with buttons (without attachments), (2) buttons on canines (with attachments), (3) precision cuts on the canines (without attachments), and (4) precision cuts on the canines (with attachments). A distalization force of 1.5 N was applied to the button or precision cut at -30°, -20°, -10°, 0°, 10°, 20°, and 30° to the occlusal plane. RESULTS As the direction of force approached +30°, the dentition inclined posteriorly. The posterior movement pattern was significantly influenced by the presence of an attachment and the direction of force, rather than the area where the force was applied. Distal inclination was dramatically reduced with attachments. A disengagement or deformation of the CA may reduce the distalization efficiency of the dentition or move the dentition in an inappropriate direction. CONCLUSIONS Attachments for efficient distalization by the CA are necessary. The use of miniscrews in the direction of force parallel to the occlusal plane is more advantageous than the use of Class II elastics. Due to CA deformation, distalization with the button on the canines can be more effective for distal movement of the maxillary dentition.
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Castroflorio T, Sedran A, Parrini S, Garino F, Reverdito M, Capuozzo R, Mutinelli S, Grybauskas S, Vaitiekūnas M, Deregibus A. Predictability of orthodontic tooth movement with aligners: effect of treatment design. Prog Orthod 2023; 24:2. [PMID: 36642743 PMCID: PMC9840984 DOI: 10.1186/s40510-022-00453-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/17/2022] [Indexed: 01/17/2023] Open
Abstract
BACKGROUNDS The present study was designed to define: (1) which are the less predictable OTM with Invisalign aligners when the treatment plan is designed by expert operators, (2) if the presence and shape of attachments influence the predictability of OTM and (3) if patients' demographics influence OTM predictability. The sample comprises 79 prospectively recruited patients (mean age 30.8 years; SD 12.0; 23 M, 56 F), treated by expert operators with an average of 27 aligners (SD 15) in the maxillary arch and 25 aligners (SD 11) in the mandibular arch. Post-treatment digital models and final virtual treatment plan models were exported from ClinCheck® software as STL files and subsequently imported into Geomagic Qualify ®software, to compare final teeth positions. The differences were calculated and tested for statistical significance for each tooth in the mesial-distal, vestibular-lingual and occlusal-gingival directions, as well as for angulation, inclination and rotation. In addition, the statistical significance of categorical variables was tested. RESULTS The lack of correction was significant for all movements and in all group of teeth (P < 0.01) except for the rotation of maxillary first molar. The prescribed OTM, the group of teeth and movement, the frequency of aligner change and the use of attachment influence the outcome. The greatest discrepancies in predicted and achieved tooth position were found for angular movements and rotation of teeth characterized by round-shaped crowns, for a ratio of approximately 0.4° per 1° prescribed. Optimized attachments for upper canines and lower premolar rotation seem not working properly. Second molar movements are mostly unexpressed. Furthermore, changing the aligner every 14 days will reduce the lack of correction of the 12% with respect to 7 days aligner change. CONCLUSIONS Predictability of orthodontic movement with aligners still has limitations related to the biomechanics of the system: the shape of some attachments and the characteristics of aligner material need to be redefined. However, the results of this study allow to properly design the virtual treatment plan, revealing how much overcorrection is needed and which attachments are most effective.
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Affiliation(s)
- Tommaso Castroflorio
- Department of Surgical Sciences, Dental School of the University of Torino, Via Nizza 230, 10126, Turin, Italy
| | - Ambra Sedran
- Department of Surgical Sciences, Dental School of the University of Torino, Via Nizza 230, 10126, Turin, Italy.
| | | | | | | | | | - Sabrina Mutinelli
- Department of Neuroscience, School of Dentistry, Section of Pedodontics, University of Padova, Via VII Febbraio 2, 35122, Padua, Italy
| | | | | | - Andrea Deregibus
- Department of Surgical Sciences, Dental School of the University of Torino, Via Nizza 230, 10126, Turin, Italy
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Customized adjuncts with clear aligner therapy: "The Golden Circle Model" explained! J World Fed Orthod 2022; 11:216-225. [PMID: 36400659 DOI: 10.1016/j.ejwf.2022.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022]
Abstract
Clear aligners are the most debated infusion of technology into the orthodontic stratosphere and currently account for a sizable chunk of the orthodontic commercial market. Data indicate that a series of plastic aligners alone cannot resolve all the variants of malocclusion routinely treated by our specialty. Current literary consensus exists that the discrepancy between the predicted and actual clinical outcomes with clear aligner therapy (CAT) is around 50% or more, necessitating midcourse corrections, refinement, or additional aligners, or even a conversion to fixed appliances before the end of treatment. A practical panacea to improve the predictability of CAT is the addition of creative and customized adjuncts to CAT. This article, inspired by the "Golden Circle Model", addresses questions such as the "WHY, HOW, and WHAT" of adjuncts used in combination with CAT and depicts an "inside out" approach (from WHY to WHAT) to present the rationale, stepwise clinical workflow, and the advantages of these adjuncts. The bootstrap, mini pin-supported mesialization or distalization, Yin-Yang attachments, Beneslider, Mesialslider, BMX Expander, and Computer-Aided Design (CAD) / Computer-Aided-Manufacturing (CAM)...based innovative appliance designs among others, are presented as adjuncts to CAT in this article. These adjuncts can either be used concomitantly with the aligners or planned as a separate phase of treatment before the commencement of the actual CAT, based on the type of tooth movement required and whether the planned tooth movement is indicated for a single tooth or a group of teeth. An astute clinician who wishes to expand the repertoire of malocclusions that can be successfully managed by CAT should judiciously plan the inclusion of such adjunct appliances in their aligner treatment planning.
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Oliveira P, Bugaighis I, Nunes Costa H, Mariano Pereira P. Perception of Need for Further Refinement in a Clear Aligner Treatment among Orthodontists, Dentists and Laypeople: A Retrospective Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15498. [PMID: 36497574 PMCID: PMC9741232 DOI: 10.3390/ijerph192315498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Clear aligner treatment often requires further refinement to improve the orthodontic treatment outcome. However, the perceptions of treatment outcomes evaluated by orthodontists and dentists are sparse, and laypeople's perceptions have yet to be explored. Here, we explore the perceptions of orthodontists, dentists, and laypeople concerning the treatment outcomes achieved after completing the first sequence of aligners. This cross-sectional study involved 37 orthodontists, 67 dentists, and 93 laypeople. We administered an online questionnaire containing intra-oral photographs of nine completed cases with pre- and post-first sequences of aligners. As a control, we used a digital prediction system for the treatment outcome. Self-perception was reported using a visual analog scale. Both orthodontists and dentists had similar perceptions about treatment outcomes (p = 0.363) but significantly differed from laypeople (p ≤ 0.0001). Both orthodontists and dentists recommended further treatment; orthodontists were more critical than dentists (p ≤ 0.001). Orthodontists were more critical than dentists in their evaluations of the need for further treatments; however, their perceptions of treatment outcomes were similar. Laypeople were more satisfied with the treatment outcomes, were less concerned with occlusion, and were more focused on the aesthetic results of the treatment.
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Affiliation(s)
- Patrícia Oliveira
- Department of Orthodontics, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
| | - Iman Bugaighis
- Department of Orthodontics, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
- The Libyan Authority for Scientific Research, Tripoli P.O. Box 80045, Libya
| | - Hélder Nunes Costa
- Department of Orthodontics, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
| | - Pedro Mariano Pereira
- Department of Orthodontics, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Egas Moniz—Cooperativa de Ensino Superior CRL, Monte da Caparica, 2829-511 Almada, Portugal
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Liu JQ, Zhu GY, Wang YG, Zhang B, Wang SC, Yao K, Zhao ZH. Different biomechanical effects of clear aligners in bimaxillary space closure under two strong anchorages: finite element analysis. Prog Orthod 2022; 23:41. [DOI: 10.1186/s40510-022-00435-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Clear aligner (CA) treatment has been gaining popularity, but the biomechanical effects of CAs in bimaxillary dentition have not been thoroughly investigated. Direct and indirect strong anchorages are two common anchorage control methods, but the underlying biomechanical mechanism has not yet been elucidated. This study aimed to investigate the different biomechanical effects of CAs in closing the bimaxillary space under different anchorage controls, further instructing the compensation strategies design and strong anchorage choice in clinical practice.
Methods
Three-dimensional (3D) bimaxillary models of different anchorage controls were created based on cone-beam computed tomography and intraoral scan data. Four first premolars were extracted using 3D modeling software. Finite element analysis was conducted to simulate the space closure process of the CAs.
Results
In the two strong anchorage groups, the bimaxillary dentition presented different movement patterns during the space closure process, and the lower dentition was more vulnerable to elastic force. From the vertical view, direct strong anchorage with elastic force had the advantage of flattening the longitudinal occlusal curve and resisting the roller-coaster effects, whereas indirect strong anchorage could lead to a deep longitudinal occlusal curve. From the sagittal view, indirect strong anchorage with metallic ligaments had a greater instantaneous anchorage protection effect, particularly in the lower dentition, which reduced the mesial movement of the posterior teeth by nearly four times that of the direct anchorage group. In addition, indirect strong anchorage presented better anterior teeth torque/tipping control, while direct strong anchorage could aggravate lingual tipping of the upper central incisors. Due to the differences in anterior–posterior anchorage and arch shape, compared with the upper dentition, anchorage preservation and vertical control effects were amplified in the lower dentition.
Conclusions
The biomechanical effects of CAs differed between the two strong anchorage groups. Due to the differences in dentition morphology, anterior–posterior anchorage, and dental arch shape, CAs present different biomechanical effects in bimaxillary space closure. Orthodontists should consider the corresponding mechanical compensation according to specific anchorage control methods and dentitions.
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Predictability of lower incisor tip using clear aligner therapy. Prog Orthod 2022; 23:37. [PMCID: PMC9637687 DOI: 10.1186/s40510-022-00433-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/03/2022] [Indexed: 11/09/2022] Open
Abstract
Abstract
Background
Uprighting incisors is particularly important with clear aligner therapy as incisor tip determines the mesio-distal space needed in the arch, and consequently the fit of the aligner. The objective of this study was to investigate the accuracy of ClinCheck® software to predict lower incisor tip by comparing digitally prescribed movements with actual clinical outcomes and to determine whether the presence of a vertically orientated rectangular composite attachment influences the efficacy of incisor tip.
Methodology
This retrospective study included 66 lower incisors from 42 non-extraction adult patients treated using the Invisalign® appliance. Twenty-one incisors had vertical attachments, while 45 incisors did not have any attachments. Lower incisor tip was measured at T0 (pre-treatment), T1 (predicted post-treatment) and T2 (achieved post-treatment) on digital models using metrology software. The change in position from T0 to T1 and T0 to T2 was measured from the estimated centre of resistance (CRes) of each tooth. The estimated centre of rotation was plotted relative to the CRes to describe the type of orthodontic tooth movement (OTM) predicted and achieved.
Results
Predicted incisor tip and achieved incisor tip were positively correlated (R2 = 0.55; p < 0.001). For every degree of tip planned 0.4 degrees of tip was achieved. The presence of an attachment resulted in 1.2 degrees greater tip (F = 3.7; p = 0.062) and 0.5 mm greater movement of the predicted apex of the tooth (F = 4.3; p = 0.042) compared with the no attachment group. The type of OTM achieved differed from the type predicted. Sixty-seven percent of incisors investigated were predicted to move by root movement, while 46% achieved this type of movement.
Conclusions
The amount of lower incisor tip achieved was on average substantially less than the ClinCheck® displayed. Vertically orientated rectangular attachments are recommended where large root movement is planned, and their presence slightly improves apex movement.
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Fan D, Liu H, Yuan CY, Wang SY, Wang PL. Effectiveness of the attachment position in molar intrusion with clear aligners: a finite element study. BMC Oral Health 2022; 22:474. [PMID: 36348394 PMCID: PMC9644447 DOI: 10.1186/s12903-022-02472-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/22/2022] [Indexed: 11/09/2022] Open
Abstract
Objective To evaluate the biomechanical effects of different attachments’ position for maxillary molar intrusion with clear aligner treatment by finite element analysis. Methods Cone-beam computed tomography images of a patient with supra-eruption of the maxillary second molars were selected to construct three-dimensional models of the maxilla, periodontal ligaments, dentition, and clear aligner. The models were divided into four groups depending on the attachment location on the first molar: (1) no attachment (NA), (2) buccal attachment (BA), (3) palatal attachment (PA), and (4) bucco-palatal attachment (BPA). After applying an intrusion of 0.2 mm on the second molar, displacements and stress distributions of the teeth, aligner, and periodontal ligament were analyzed with the finite element software. Results All groups displayed equivalent movement patterns of aligners. The NA and BA groups showed buccal tipping of the second molar, while the PA group showed palatal tipping. The BPA group had the highest intruding value and the lowest buccal/palatal tipping value. All groups showed mesial tipping of the second molar. Stress distribution in the periodontal ligament strongly correlated with the attachment position. The BPA group showed the best stress distribution. Conclusion Combined BA and PA could effectively prevent buccal and palatal tipping and showed the best efficiency in intruding the second molar. The second molar showed an unavoidable tendency to tip mesially, regardless of the attachment position.
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Chi J, Yang L, Liu Y, Yang J, Deng J. Biomechanical Characteristics of Maxillary Molar Distalization Using Different Attachments with Clear Aligners: A 3-Dimensional Finite Element Analysis. J BIOMATER TISS ENG 2022. [DOI: 10.1166/jbt.2022.3094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to compare the biomechanical characteristics of maxillary teeth in molar distalization with different orthodontic attachments. A 3-dimensional finite model of maxillary molar distalization with clear aligners was generated by computed tomography and contained different
components. Four models—non-attachment (model A), horizontal rectangular attachment (model B), vertical rectangular attachment (model C), and combined attachment (model D)—were set up. The modalities of molar distalization were simulated using a finite element analysis. The results
showed that the minimum displacement (rotation center) of the second molar in models A and B was located at the root furcation. In model C, the minimum displacement was located in the middle third of the palatal root. In model D, the minimum displacement was located at the apical third of
the root. The anchorage teeth in all the four groups tended to have mesial tipping movement. Models B and D had more uniform stress distribution of the periodontal ligament than models A and C. Models with attachment had a larger tooth displacement pattern than that without attachment. Collectively,
if molar distalization is planned before treatment, the appropriate application of attachments can help achieve the desired tooth movements more efficiently.
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Affiliation(s)
- Jingwen Chi
- School of Stomatology, Qingdao University, Qingdao, 266003, China
| | - Lixia Yang
- School of Stomatology, Qingdao University, Qingdao, 266003, China
| | - Yicong Liu
- School of Stomatology, Qingdao University, Qingdao, 266003, China
| | - Jianjun Yang
- Department of Oral and Maxillofacial Surgery, Affiliated Hospital, Qingdao University, Qingdao, 266001, China
| | - Jing Deng
- School of Stomatology, Qingdao University, Qingdao, 266003, China
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Cheng Y, Gao J, Fang S, Wang W, Ma Y, Jin Z. Torque movement of the upper anterior teeth using a clear aligner in cases of extraction: a finite element study. Prog Orthod 2022; 23:26. [PMID: 35909188 PMCID: PMC9339452 DOI: 10.1186/s40510-022-00421-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/30/2022] [Indexed: 11/10/2022] Open
Abstract
Background Clear aligner treatment has become popular over recent years. It is necessary to identify methods by which we could avoid the bowing effect in extractions with clear aligner. The present study was to identify the appropriate method to design torque movement involving the upper anterior teeth of extraction cases, in order to maintain or improve the axis and torque of the upper anterior teeth with a clear aligner during movement and closure of the extraction space. Results As the height of the power ridge increased, the rotation angle of the upper central incisor in the sagittal direction decreased gradually and the location of the rotation center changed significantly; the rotation center moved in the apical direction and then changed to the crown side. The highest von-Mises stress of the upper central incisor root, periodontal ligaments, and alveolar bone, showed little change as the power ridge height increased. When the axial inclination of the upper central incisor was normal (U1-SN = 105°), the tendency of movement for the upper central incisor approached translation with a power ridge height of 0.7 mm (corresponding distorted angle: 5.8415). When the axial inclination of the upper central incisor was oversized (U1-SN = 110°), the axial inclination of the upper central incisor reduced to normal following completion of the anterior segment retraction with a power ridge of 0.4 mm (corresponding distorted angle: 3.4265). Conclusion Analysis indicates that pure palatal tipping movement of the upper anterior teeth is generated without torque control, thus resulting in the bowing effect. The required torque control of the upper anterior teeth with oversize axial inclination is weaker than that of the upper anterior teeth with normal axial inclination because limited torque loss is expected for oversize axial inclination teeth. Variation sensitivity of the rotation center should be considered carefully due to biological problems when designing translation of the upper anterior teeth with normal axial inclination.
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Affiliation(s)
- Yuxun Cheng
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases, Department of Orthodontics, School of Stomatology, Air Force Medical University, Xi'an, 710032, China
| | - Jie Gao
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases, Department of Orthodontics, School of Stomatology, Air Force Medical University, Xi'an, 710032, China
| | - Shishu Fang
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases, Department of Orthodontics, School of Stomatology, Air Force Medical University, Xi'an, 710032, China
| | - Wei Wang
- Urumql DW Innovation InfoTech Co., Ltd, Xinjiang, 830000, China
| | - Yanning Ma
- Shanxi Medical University School and Hospital of Stomatology, Taiyuan, 030001, China.
| | - Zuolin Jin
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases, Department of Orthodontics, School of Stomatology, Air Force Medical University, Xi'an, 710032, China.
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Ye N, Brown B, Mantell S, Heo Y, Larson B, Fok A. Validation of finite element models for orthodontic aligners. J Mech Behav Biomed Mater 2022; 134:105404. [DOI: 10.1016/j.jmbbm.2022.105404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/20/2022] [Accepted: 07/26/2022] [Indexed: 10/16/2022]
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Stephens C, Weir T, Llewellyn S, Freer E, Kerr B. Clinical expression of programmed mandibular canine rotation using various attachment protocols and 1- vs 2-week wear protocols with Invisalign SmartTrack aligners: A retrospective cohort study. Am J Orthod Dentofacial Orthop 2022; 162:e103-e115. [PMID: 35835703 DOI: 10.1016/j.ajodo.2022.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 11/01/2022]
Abstract
INTRODUCTION Rotation of rounded teeth, particularly canines, is reported as one of the most difficult and inaccurate tooth movements with aligners. This retrospective study aimed to assess the accuracy and reliability of prescribed mandibular canine rotation with Invisalign aligners and the influence of attachment type and wear schedule on accuracy. METHODS A sample of 75 subjects with mandibular canines requiring rotation was collected from an existing database. The initial, predicted finish, and achieved finish, were measured using metrology software, and the differences between predicted and achieved mandibular canine rotations were calculated. The sample was divided into 3 groups: optimized rotation attachments using 1-week wear, optimized rotation attachments using 2-week wear, and conventional rectangular attachments using 2-week wear. RESULTS Rotation was an underexpressed movement, with an overall median sample efficiency of 75.4%. For all groups, predicted rotation was not equivalent to achieved rotation at a ± 5° equivalence margin. This indicates that none of the Invisalign SmartTrack aligner attachment configurations display clinical accuracy in their predicted rotation. By attachment type, median efficiencies of 81.5%, 76.5%, and 63.1% were found for groups 1-week wear, 2-week wear, and 2-week wear, respectively. By wear schedule, there was no significant difference in efficiency for optimized rotation attachments. CONCLUSIONS The clinical expression of canine rotation with SmartTrack aligners is less than the prescribed rotation for all attachment configurations. Vertical rectangular attachments were associated with the least accurate expression of prescribed movement. There was no difference in rotation efficiency between 1- or 2-week aligner wear.
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Affiliation(s)
- Caitlin Stephens
- Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia.
| | - Tony Weir
- Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia
| | - Stacey Llewellyn
- Statistics Unit, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Elissa Freer
- Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia
| | - Brett Kerr
- Department of Orthodontics, School of Dentistry, University of Queensland, Brisbane, Queensland, Australia
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Wang Q, Dai D, Wang J, Chen Y, Zhang C. Biomechanical analysis of effective mandibular en-masse retraction using Class II elastics with a clear aligner: a finite element study. Prog Orthod 2022; 23:23. [PMID: 35811318 PMCID: PMC9271451 DOI: 10.1186/s40510-022-00417-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Background This study aimed to evaluate the displacement and stress distribution of mandibular dentition by various positions of the Class II elastics during en-masse retraction in clear aligner therapy. Methods Models including a mandibular dentition (without first premolars), periodontal ligament (PDL), mandible, as well as attachments, aligners and buttons were constructed and imported into Ansys Workbench 2019 (ANSYS, USA) to generate the three-dimensional (3D) finite element model. Six combinations were created: (1) aligner alone (control), (2)-(5) Class II elastics with buttons placed on the mesiobuccal (MB), distobuccal (DB), mesiolingual (ML) and distolingual (DL) surface of the mandibular first molar, and (6) Class II elastics with a button on the aligner corresponding to the mesiobuccal surface of the mandibular first molar (AMB). The elastic force was set to 2 N for simulations. Results The central incisors appeared lingual tipping in the six models. The lingual crown movement of the central incisors was 0.039 mm, 0.034 mm, 0.034 mm, 0.042 mm, 0.041 mm, and 0.034 mm for control model, MB model, DB model, ML model, DL model, and AMB model, respectively. The first molars showed mesial tipping in the six models. The mesial movement of the mesiobuccal cusps of the first molars was 0.045 mm, 0.060 mm, 0.063 mm, 0.048 mm, 0.051 mm, and 0.055 mm for control model, MB model, DB model, ML model, DL model, and AMB model, respectively. Conclusions Class II elastics reduced lingual tipping of anterior teeth but aggravated mesial tipping of posterior teeth. Mesiolingual elastics developed minimum mesial tipping of the posterior teeth. When Class II elastics are required, attaching elastics on the mesiolingual surface of the mandibular first molar is recommended to prevent mandibular anchorage loss.
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Zhu C, Li R, Yuan L, Zheng Y, Jin Y, Li H, Liu C, Xia L, Fang B. Effects of the advanced mandibular spring on mandibular retrognathia treatment: a three-dimensional finite element study. BMC Oral Health 2022; 22:271. [PMID: 35790937 PMCID: PMC9254520 DOI: 10.1186/s12903-022-02308-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/29/2022] [Indexed: 12/03/2022] Open
Abstract
Background The Advanced Mandibular Spring (AMS) was newly developed as a dentofacial orthopedic appliance in conjunctive use of clear aligners to treat Class II malocclusion with mandibular retrognathia in adolescents. This study aimed to launch a biomechanical assessment and evaluate whether the stress patterns generated by AMS promote mandibular growth. Methods A three-dimensional finite element model was constructed using images of CBCT and spiral CT. The model consisted of craniomaxillofacial bones, articular discs, retrodiscal elastic stratum, masticatory muscle, teeth, periodontal ligament, aligner and AMS. Mechanical effects were analyzed in three types of models: mandibular postural position, mandibular advancement with AMS, and mandibular advancement with only muscular force. Results The stress generated by AMS was distributed to all teeth and periodontal ligament, pushing mandibular teeth forward and maxillary teeth backward. In the temporomandibular joint area, the pressure in the superior and posterior aspects of the condyle was reduced, which conformed to the stress pattern promoting condylar and mandibular growth. Stress distribution became even in the anterior aspect of the condyle and the articular disc. Significant tensile stress was generated in the posterior aspect of the glenoid fossa, which conformed to the stress pattern stimulating the remodeling of the fossa. Conclusions AMS created a favorable biomechanical environment for treating mandibular retrognathia in adolescents. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-022-02308-w.
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Initial Displacement and Stress Distribution of Upper Central Incisor Extrusion with Clear Aligners and Various Shapes of Composite Attachments Using the Finite Element Method. Dent J (Basel) 2022; 10:dj10060114. [PMID: 35735656 PMCID: PMC9222152 DOI: 10.3390/dj10060114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 12/04/2022] Open
Abstract
A clear aligner is an esthetic and more comfortable option for patients who need orthodontic treatment. However, some types of tooth movement, such as extrusion, are difficult with this tool. Therefore, composite attachments have been suggested to improve tooth movement. This study aims to evaluate the initial displacement and stress distribution during upper central incisor extrusion using the conventional composite attachments. Maxillary models with the upper teeth, clear aligners, and composite attachments placed on the labial surface of the upper right central incisor were constructed. Four models were created to simulate upper central incisor extrusion: (1) without any composite attachment; (2) rectangular beveled attachment; (3) ellipsoid attachment; and (4) horizontal rectangular attachment. Clear aligners were designed to perform upper central incisor extrusion. The constructed models were analyzed using the finite element method. Initial displacement and stress distribution were analyzed. Output analysis found that the upper right central incisor in the model with a horizontal rectangular attachment had the greatest extrusive movement, followed by the model with ellipsoid attachment and the model with beveled attachment. Maximum compressive stress was seen at the cervical region of the composite attachment. Composite attachments including horizontal rectangular attachment, ellipsoid attachment, and rectangular beveled attachment can be used to perform upper central incisor extrusion.
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Does Sex, Skeletal Class and Mandibular Asymmetry Affect Tooth Length and Asymmetry in Tooth Length? Symmetry (Basel) 2022. [DOI: 10.3390/sym14051069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Introduction: The aim of our cross-sectional study is to determine whether there is a link between sex, skeletal class and mandibular asymmetry in orthodontic patients, with tooth length and asymmetry in tooth length on contralateral sides of the mandible. Methods: As the source for relevant data to answer this question, 3D cone-beam tomography (CBCT) images of a total of 95 future orthodontic patients were retrospectively selected from private practice records and were analyzed. The CBCT images were part of routine orthodontic diagnosis. Patients were divided into three groups (Class I, Class III with asymmetry and Class III without asymmetry) based on skeletal variables assessed on orthodontic cephalometric images and frontal photos of the face. Three null hypotheses were developed, and a series of statistical tests was performed in order to support or reject them. Results: We have established that there exists a sexual dimorphism in some of the teeth’s lengths in our sample. Furthermore, we failed to find a link between mandibular asymmetry and asymmetry in tooth length. We have also found a link between skeletal class and tooth length differences in some of the analyzed measurements. Conclusions: Computational models used to design orthodontic appliances and to plan orthodontic treatment should be more individualized to consider a patient’s sex and skeletal class.
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Ferlias N, Dalstra M, Cornelis MA, Cattaneo PM. In Vitro Comparison of Different Invisalign® and 3Shape® Attachment Shapes to Control Premolar Rotation. Front Bioeng Biotechnol 2022; 10:840622. [PMID: 35372304 PMCID: PMC8966893 DOI: 10.3389/fbioe.2022.840622] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Abstract
Aim: To evaluate in vitro the differences of various Invisalign® attachments in their effectiveness during derotation of an upper second premolar in terms of forces and moments created and compare them to the 3Shape® box attachment as well as to no attachment at all.Materials and Methods: A Force System Identification (FSI) machine, comprising two load sensors, was used in this study. Sensor 1 was connected to the test tooth (i.e. upper second premolar) carrying a different attachment design, and the fixed sensor (Sensor 2) was connected to the base model. Once the corresponding aligner was passively seated on the teeth, 12 different setups (i.e. 11 different attachments and one setup with no attachment at all) were tested by rotating the test tooth 4.5° mesially and 4.5° distally, in increments of 0.45°.Results: The vertical rectangular attachments were able to generate the highest derotational moment on both mesial and distal rotations but also received the most side effects (intrusive force, torque, and tipping). The no-attachment setup performed least favorably in terms of derotational ability but exhibited the least side effects. In the y-axis, all attachments received a buccal root torque with a lingual force during disto-rotation and a lingual root torque with a buccal force during mesio-rotation.Conclusion: Attachments are necessary for derotating an upper second premolar. An aligner incremental change of more than 1° derotation can generate high moments. The vertical rectangular attachments perform best in derotations; however, they exhibit the most side effects. Finally, despite presenting the least side effects, derotation of a premolar with no attachment is not as efficient.
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Affiliation(s)
- Nikolaos Ferlias
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
- *Correspondence: Nikolaos Ferlias,
| | - Michel Dalstra
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Marie A. Cornelis
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Paolo M. Cattaneo
- Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
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Talens-Cogollos L, Vela-Hernández A, Peiró-Guijarro MA, García-Sanz V, Montiel-Company JM, Gandía-Franco JL, Bellot-Arcís C, Paredes-Gallardo V. Unplanned molar intrusion after Invisalign treatment. Am J Orthod Dentofacial Orthop 2022; 162:451-458. [DOI: 10.1016/j.ajodo.2021.03.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 11/01/2022]
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Liu L, Song Q, Zhou J, Kuang Q, Yan X, Zhang X, Shan Y, Li X, Long H, Lai W. The effects of aligner overtreatment on torque control and intrusion of incisors for anterior retraction with clear aligners: A finite-element study. Am J Orthod Dentofacial Orthop 2022; 162:33-41. [DOI: 10.1016/j.ajodo.2021.02.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 01/22/2023]
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Nucera R, Dolci C, Bellocchio AM, Costa S, Barbera S, Rustico L, Farronato M, Militi A, Portelli M. Effects of Composite Attachments on Orthodontic Clear Aligners Therapy: A Systematic Review. MATERIALS 2022; 15:ma15020533. [PMID: 35057250 PMCID: PMC8778413 DOI: 10.3390/ma15020533] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/20/2021] [Accepted: 01/04/2022] [Indexed: 12/26/2022]
Abstract
This systematic review aims to highlight the differences between different clear aligner therapies that differ in the presence of attachments or in attachment configuration. Eight electronic databases were searched up to March 2020. Two authors independently proceeded to study selection, data extraction, and risk of bias assessment. The analysis of the results was carried out examining six groups of movements (mesio-distal tipping/bodily movement; anterior bucco-lingual tipping/root torque; posterior bucco-lingual tipping/expansion; intrusion; extrusion; rotation). Five clinical trials were selected and all of them showed a medium risk of bias. Literature showed that attachments mostly increase the effectiveness of orthodontic treatment with clear aligners, improving anterior root torque, rotation, and mesio-distal (M-D) movement; they are also important to increase posterior anchorage. However, some articles showed contradictory or not statistically significant results. Attachments also seem to improve intrusion, but the evidence about this movement, as well as extrusion, is lacking. No studies evaluated posterior bucco-lingual tipping/expansion. Further clinical trials are strongly suggested to clarify the influence of attachments and their number, size, shape, and position on each orthodontic movement.
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Affiliation(s)
- Riccardo Nucera
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Carolina Dolci
- Department of Biomedical, Surgical and Dental Sciences, Fondazione IRCCS Cà Granda—Ospedale Maggiore Policlinico, University of Milan, 20122 Milan, Italy; (C.D.); (M.F.)
| | - Angela Mirea Bellocchio
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Stefania Costa
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Serena Barbera
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Lorenzo Rustico
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Marco Farronato
- Department of Biomedical, Surgical and Dental Sciences, Fondazione IRCCS Cà Granda—Ospedale Maggiore Policlinico, University of Milan, 20122 Milan, Italy; (C.D.); (M.F.)
| | - Angela Militi
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
| | - Marco Portelli
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Section of Orthodontics, University of Messina, 98125 Messina, Italy; (R.N.); (A.M.B.); (S.C.); (S.B.); (L.R.); (A.M.)
- Correspondence: ; Tel.: +39-0902216905
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Upadhyay M, Arqub SA. Biomechanics of clear aligners: hidden truths & first principles. J World Fed Orthod 2021; 11:12-21. [PMID: 34965910 DOI: 10.1016/j.ejwf.2021.11.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 11/23/2021] [Indexed: 11/19/2022]
Abstract
Over the past two decades clear aligner-based treatment has received remarkableattention from the orthodontic profession and more so from general practitioners.Different companies have emerged using vigorous advertisement to promote theirproducts mainly to patients and clinicians through social media. A variety of concepts,methods, and adjuncts have been introduced to enhance the efficacy andeffectiveness of clear aligners. However, the accuracy of tooth movement (vspredicted) with aligners still hovers around 50%. Fixed appliances fare much better onaccuracy and predictability of treatment. Why is there a discrepancy betweenexpected and actual outcomes? This paper utilizes 'first principles' and the existingevidence to unravel some of the key drawbacks of aligner-based therapy. Severalshortcomings in the biomechanical properties of aligner material (thermoplastics) thataffect clinical performance are discussed. Based on the first principles of alignerbiomechanics, this paper provides clinical insights for improving predictability and effectiveness of aligner therapy.
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Affiliation(s)
- Madhur Upadhyay
- Division of Orthodontics, University of Connecticut Health, Farmington, Connecticut, USA.
| | - Sarah Abu Arqub
- Division of Orthodontics, University of Connecticut Health, Farmington, Connecticut, USA
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Voudouris JC, Voudouris JD, Nicolay O, Glaser B, Nicozisis J, Theodoridis G, Carrillo R, Moshiri M, Masoud M. TEMPORARY REMOVAL: Clear Aligners, Dentofacial Orthopedics, Physics and Supercorrection Biomechanics. A Meeting of the Minds. Semin Orthod 2021. [DOI: 10.1053/j.sodo.2021.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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