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Haas E, Schmid A, Stocker T, Wichelhaus A, Sabbagh H. Force-Controlled Biomechanical Simulation of Orthodontic Tooth Movement with Torque Archwires Using HOSEA (Hexapod for Orthodontic Simulation, Evaluation and Analysis). Bioengineering (Basel) 2023; 10:1055. [PMID: 37760157 PMCID: PMC10525810 DOI: 10.3390/bioengineering10091055] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
This study aimed to investigate the dynamic behavior of different torque archwires for fixed orthodontic treatment using an automated, force-controlled biomechanical simulation system. A novel biomechanical simulation system (HOSEA) was used to simulate dynamic tooth movements and measure torque expression of four different archwire groups: 0.017″ x 0.025″ torque segmented archwires (TSA) with 30° torque bending, 0.018″ x 0.025″ TSA with 45° torque bending, 0.017″ x 0.025″ stainless steel (SS) archwires with 30° torque bending and 0.018″ x 0.025″ SS with 30° torque bending (n = 10/group) used with 0.022″ self-ligating brackets. The Kruskal-Wallis test was used for statistical analysis (p < 0.050). The 0.018″ x 0.025″ SS archwires produced the highest initial rotational torque moment (My) of -9.835 Nmm. The reduction in rotational moment per degree (My/Ry) was significantly lower for TSA compared to SS archwires (p < 0.001). TSA 0.018″ x 0.025″ was the only group in which all archwires induced a min. 10° rotation in the simulation. Collateral forces and moments, especially Fx, Fz and Mx, occurred during torque application. The measured forces and moments were within a suitable range for the application of palatal root torque to incisors for the 0.018″ x 0.025″ archwires. The 0.018″ x 0.025″ TSA reliably achieved at least 10° incisal rotation without reactivation.
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Affiliation(s)
| | | | | | | | - Hisham Sabbagh
- Department of Orthodontics and Dentofacial Orthopedics, LMU University Hospital, LMU Munich, Goethestraße 70, 80336 Munich, Germany; (E.H.); (A.S.); (T.S.); (A.W.)
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Kandil A, Elkordybhelped SA, Labibchelped A, Harzerdhelped W, Bourauelesupervised C. Evaluation of SARDAC Technique during En-masse Retraction in Lingual Orthodontics. Semin Orthod 2023. [DOI: 10.1053/j.sodo.2023.01.003] [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: 01/30/2023]
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Xu Y, Yu L, Tong X, Wang Y, Li Y, Pan J, Yang Y, Liu Y. Efficacy and safety of piezocision in accelerating maxillary anterior teeth en-masse retraction: study protocol for a randomized controlled trial. Trials 2022; 23:476. [PMID: 35672789 PMCID: PMC9171929 DOI: 10.1186/s13063-022-06389-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Orthodontic treatment is commonly more time-consuming in adults than in teenagers, especially when it comes to the maxillary en-masse retraction, which may take 9 months or even longer. As to solve this concern, orthodontists have been striving to seek new methods for shortening orthodontic treatment time. Piezocision, as a popular alternative treatment, has been widely used in different types of tooth movement. However, its effect on en-masse retraction of maxillary anterior teeth remains unclear. This randomized controlled trial intends to figure out the role piezocision plays in accelerating en-masse retraction. METHODS This protocol is designed for a prospective, single-center, assessor-blinded and parallel-group randomized controlled trial. Twenty adult patients aged from 18 to 40 whose orthodontic treatment required bilateral maxillary first premolars extraction will be randomly assigned to the piezocision group and the control group at a ratio of 1:1. The piezocision group will undergo en-masse retraction immediately after the piezo surgery, while the control group will start en-masse retraction directly. Both groups will be followed up every 2 weeks to maintain the retraction force until the end of space closure. The space closing time is set as the primary endpoint. Meanwhile, the secondary endpoints include the change of root length, labial and palatal alveolar bone thickness, vertical bone height, probing depth of maxillary anterior teeth, cephalometric measurements, visual analogue scale, and postoperative satisfaction questionnaire. DISCUSSION This study will attempt to provide more convincing evidence to verify whether piezocision will shorten the time of en-masse retraction or not. Distinguished with previous studies, our study has made some innovations in orthodontic procedure and primary outcome measurement, aiming to clarify the efficacy and safety of piezocision-assisted en-masse retraction in Chinese population. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR 1900024297 . Registered on 5 July 2019.
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Affiliation(s)
- Yichen Xu
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
| | - Liming Yu
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
| | - Xianqin Tong
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
| | - Yuhui Wang
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
| | - Yuanyuan Li
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
- Department of Pediatric Dentistry, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
| | - Jie Pan
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
| | - Yanjing Yang
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China
- Department of Pediatric Dentistry, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China
| | - Yuehua Liu
- Department of Orthodontics, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China.
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China.
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Evaluation of stress pattern in periodontium and change in inclination during en masse retraction: Finite element analysis. J World Fed Orthod 2019. [DOI: 10.1016/j.ejwf.2019.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ruenpol N, Sucharitpwatskul S, Wattanawongskun P, Charoenworaluck N. Force direction using miniscrews in sliding mechanics differentially affected maxillary central incisor retraction: Finite element simulation and typodont model. J Dent Sci 2019; 14:138-145. [PMID: 31205605 PMCID: PMC6558348 DOI: 10.1016/j.jds.2019.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/02/2018] [Indexed: 11/29/2022] Open
Abstract
Background/purpose En masse retraction was still controversy in orthodontics. The aim of this study was to investigate the effect of force directions created by different miniscrew positions and lever arm heights on maxillary central incisor movement using Finite Element (FE) simulation and a Typodont model. Materials and methods A typodont model and 3-dimensional FE were used to simulate en masse anterior teeth retraction in sliding mechanics. The lever arm and the miniscrew positions were varied to change the force direction. The maxillary central incisor displacement was recorded and analyzed. Results The typodont results revealed that miniscrew vertical position and lever arm height affected the type of tooth movement. The best control in the vertical plane was achieved by a 7 mm lever arm height and miniscrew 9 mm from the archwire. When the lever arm height and miniscrew were 7 mm from the archwire, the tooth extruded. When the lever arm height was 9 mm and the miniscrew was 7 or 9 mm from the archwire, the tooth intruded. The FE stimulation determined that near bodily movement of the maxillary central incisor was achieved when the lever arm height and miniscrew was 9 mm from the archwire. The highest strain distribution in the periodontal ligament was observed at the apical third of the lateral incisor. Conclusion In en masse retraction, the appropriate direction of force or the height of the miniscrew and the lever arm may enable orthodontists to maintain better control of the anterior teeth in sliding mechanics.
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Affiliation(s)
- Nantaporn Ruenpol
- Faculty of Dentistry, Thammasat University, Pathum Thani, 12120, Thailand
| | | | - Prasit Wattanawongskun
- National Metal and Materials Technology Center, Thailand Science Park, Pathum Thani, 12120, Thailand
| | - Nongluck Charoenworaluck
- Faculty of Dentistry, Thammasat University, Pathum Thani, 12120, Thailand
- Corresponding author. Fax: +66 2 986 9205.
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Suzuki M, Sueishi K, Katada H, Togo S. Finite Element Analysis of Stress in Maxillary Dentition during En-masse Retraction with Implant Anchorage. THE BULLETIN OF TOKYO DENTAL COLLEGE 2019; 60:39-52. [PMID: 30700640 DOI: 10.2209/tdcpublication.2017-0055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The goal of this study was to investigate how the height of the archwire hook and implant anchor affect tooth movement, stress in the teeth and alveolar bone, and the center of resistance during retraction of the entire maxillary dentition using a multibracket system. Computed tomography was used to scan a dried adult human skull with normal occlusion. Three-dimensional models of the maxillary bone, teeth, brackets, archwire, hook, and implant anchor were created and used for finite element analysis. The heights of the hook and the implant anchor were set at 0, 5, or 10 mm from the archwire. Orthodontic force of 4.9 N was systematically applied between the hook and the implant anchor and differential stress distributions and tooth movements observed for each traction condition. With horizontal traction, the archwire showed deformation in the superior direction anterior to the hook and in the inferior direction posterior to the hook. Differences in traction height and direction resulted in different degrees of deformation, with biphasic movement clearly evident both in front of and behind the hook. With horizontal traction of the hook at a height of 0 mm, all the teeth moved distally, but not with any other type of traction. At a height of 5 mm or 10 mm, deformation showed an increase. The central incisor showed extrusion under all traction conditions, with the amount showing a reduction as the height of horizontal or posterosuperior traction increased. The center of resistance was located at the root of the 6 anterior teeth and entire maxillary dentition. The present results suggest that it is necessary to consider deformation of the wire and the center of resistance during en-masse retraction with implant anchorage.
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Ouejiaraphant T, Samruajbenjakun B, Chaichanasiri E. Determination of the centre of resistance during en masse retraction combined with corticotomy: finite element analysis. J Orthod 2017; 45:11-15. [PMID: 29165045 DOI: 10.1080/14653125.2017.1405138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To determine the effect of corticotomy on the change in the centre of resistance of the six maxillary anterior teeth Materials and methods: Three-dimensional finite element models of the maxillary anterior teeth with and without corticotomy were constructed. Brackets (size 0.022 inch × 0.028 inch) were placed passively on all anterior teeth that were set at the centre of the labial surface in the mesio-distal dimension and 3 mm from the incisal edge to the bracket slot in the vertical direction. The power arm was set mesial of the canine bracket. For the model with corticotomy, the bone density was decreased from initial value at 5% to 25%. The point of force application was varied in order to locate the centre of resistance. The centre of resistance was located by measurement of the difference of the displacement between the apical and incisal edges. The position of force was varied by moving apically parallel to the occlusal plane to simulate tooth movement. RESULTS As the alveolar bone density decreased from initial value to 25%, the location of the centre of resistance moved apically from the bracket slot from 10.8 mm to 11.2 mm, respectively. CONCLUSIONS The change of alveolar bone density due to corticotomy was associated with the location of the centre of resistance. The location of the centre of resistance moved apically as the alveolar bone density decreased but it was not clinically noticeable.
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Affiliation(s)
- Tanes Ouejiaraphant
- a Department of Preventive Dentistry, Faculty of Dentistry , Prince of Songkla University , Hat Yai , Songkhla , Thailand
| | - Bancha Samruajbenjakun
- a Department of Preventive Dentistry, Faculty of Dentistry , Prince of Songkla University , Hat Yai , Songkhla , Thailand
| | - Ekachai Chaichanasiri
- b Department of Mechanical Engineering, Faculty of Engineering , Mahidol University , Salaya , Nakornpathom , Thailand
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Felicita AS. Quantification of intrusive/retraction force and moment generated during en-masse retraction of maxillary anterior teeth using mini-implants: A conceptual approach. Dental Press J Orthod 2017; 22:47-55. [PMID: 29160344 PMCID: PMC5730136 DOI: 10.1590/2177-6709.22.5.047-055.oar] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/13/2017] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The aim of the present study was to clarify the biomechanics of en-masse retraction of the upper anterior teeth and attempt to quantify the different forces and moments generated using mini-implants and to calculate the amount of applied force optimal for en-masse intrusion and retraction using mini-implants. METHODS The optimum force required for en-masse intrusion and retraction can be calculated by using simple mathematical formulae. Depending on the position of the mini-implant and the relationship of the attachment to the center of resistance of the anterior segment, different clinical outcomes are encountered. Using certain mathematical formulae, accurate measurements of the magnitude of force and moment generated on the teeth can be calculated for each clinical outcome. RESULTS Optimum force for en-masse intrusion and retraction of maxillary anterior teeth is 212 grams per side. Force applied at an angle of 5o to 16o from the occlusal plane produce intrusive and retraction force components that are within the physiologic limit. CONCLUSION Different clinical outcomes are encountered depending on the position of the mini-implant and the length of the attachment. It is possible to calculate the forces and moments generated for any given magnitude of applied force. The orthodontist can apply the basic biomechanical principles mentioned in this study to calculate the forces and moments for different hypothetical clinical scenarios.
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Affiliation(s)
- A Sumathi Felicita
- Saveetha University, Saveetha Dental College, Department of Orthodontics and Dentofacial Orthopedics (Chennai, India)
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Jo AR, Mo SS, Lee KJ, Sung SJ, Chun YS. Finite-element analysis of the center of resistance of the mandibular dentition. Korean J Orthod 2016; 47:21-30. [PMID: 28127536 PMCID: PMC5266128 DOI: 10.4041/kjod.2017.47.1.21] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 07/01/2016] [Accepted: 07/05/2016] [Indexed: 11/16/2022] Open
Abstract
Objective The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.
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Affiliation(s)
- A-Ra Jo
- Department of Orthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Korea
| | - Sung-Seo Mo
- Division of Orthodontics, Department of Dentistry, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Kee-Joon Lee
- Department of Dentistry, Yonsei University, Seoul, Korea
| | - Sang-Jin Sung
- Division of Orthodontics, Department of Dentistry, Asan Medical Center, Seoul, Korea
| | - Youn-Sic Chun
- Department of Orthodontics, Ewha Womans University Mokdong Hospital, Seoul, Korea
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Saga AY, Maruo H, Argenta MA, Maruo IT, Tanaka OM. Orthodontic intrusion of maxillary incisors: a 3D finite element method study. Dental Press J Orthod 2016; 21:75-82. [PMID: 27007765 PMCID: PMC4816589 DOI: 10.1590/2177-6709.21.1.075-082.oar] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/17/2015] [Indexed: 11/22/2022] Open
Abstract
Objective: In orthodontic treatment, intrusion movement of maxillary incisors is often necessary. Therefore, the objective of this investigation is to evaluate the initial distribution patterns and magnitude of compressive stress in the periodontal ligament (PDL) in a simulation of orthodontic intrusion of maxillary incisors, considering the points of force application. Methods: Anatomic 3D models reconstructed from cone-beam computed tomography scans were used to simulate maxillary incisors intrusion loading. The points of force application selected were: centered between central incisors brackets (LOAD 1); bilaterally between the brackets of central and lateral incisors (LOAD 2); bilaterally distal to the brackets of lateral incisors (LOAD 3); bilaterally 7 mm distal to the center of brackets of lateral incisors (LOAD 4). Results and Conclusions: Stress concentrated at the PDL apex region, irrespective of the point of orthodontic force application. The four load models showed distinct contour plots and compressive stress values over the midsagittal reference line. The contour plots of central and lateral incisors were not similar in the same load model. LOAD 3 resulted in more balanced compressive stress distribution.
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Affiliation(s)
- Armando Yukio Saga
- School of Health and Biosciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil
| | - Hiroshi Maruo
- Associação Brasileira de Odontologia, Ponta Grossa, Paraná, Brazil
| | - Marco André Argenta
- Department of Civil Engineering, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Ivan Toshio Maruo
- Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil
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Factors controlling anterior torque during C-implant-dependent en-masse retraction without posterior appliances. Am J Orthod Dentofacial Orthop 2011; 140:72-80. [DOI: 10.1016/j.ajodo.2009.09.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/01/2009] [Accepted: 09/01/2009] [Indexed: 11/17/2022]
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Joo BH. A New Treatment Method to Retract Anterior Teeth with the Double J Retractor System in Class III Malocclusions. Semin Orthod 2011. [DOI: 10.1053/j.sodo.2011.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Park HK, Sung EH, Cho YS, Mo SS, Chun YS, Lee KJ. 3-D FEA on the intrusion of mandibular anterior segment using orthodontic miniscrews. Korean J Orthod 2011. [DOI: 10.4041/kjod.2011.41.6.384] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Hyun-Kyung Park
- Graduate Student, Department of Orthodontics, College of Dentisrty, Yonsei University, Korea
| | - Eui-Hyang Sung
- Graduate Student, Department of Orthodontics, College of Dentisrty, Yonsei University, Korea
| | - Young-Soo Cho
- Contract Professor, Department of Mechanical Engineering BK21, Hanyang University, Korea
| | - Sung-Seo Mo
- Assistant Professor, Department of Orthodontics, St. Mary's Hospital, The Catholic University of Korea, Korea
| | - Youn-Sic Chun
- Professor, Department of Orthodontics, Ewha Womans University Mokdong Hospital, Korea
| | - Kee-Joon Lee
- Associate Professor, Department of Orthodontics, College of Dentisrty, Oral Science Research Center, The Institute of Craniofacial Deformity, Yonsei University, Korea
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Kojima Y, Fukui H. Numerical simulations of canine retraction with T-loop springs based on the updated moment-to-force ratio. Eur J Orthod 2010; 34:10-8. [DOI: 10.1093/ejo/cjq164] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Jang HJ, Roh WJ, Joo BH, Park KH, Kim SJ, Park YG. Locating the center of resistance of maxillary anterior teeth retracted by Double J Retractor with palatal miniscrews. Angle Orthod 2010; 80:1023-8. [PMID: 20677950 DOI: 10.2319/121409-712.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To locate the center of resistance of six maxillary anterior teeth retracted by the Double J Retractor (DJR) and to find the optimal position of palatal miniscrews. MATERIALS AND METHODS The three-dimensional (3D) finite element model included 12 teeth with two first premolars extracted. The DJR was modeled as a 3D beam element. The miniscrew was sagittally placed between the second premolar and the first molar, and the vertical position of the miniscrew was established at five conditions: 6, 7, 8, 9, and 10 mm apically from the cervical line of the first molar. The length of the retraction lever arm was determined according to the position of the miniscrew, for the direction of retraction force to be parallel to the maxillary occlusal plane. The 3D finite element method was used to determine the location of the center of resistance of the maxillary anterior teeth by visualizing the tooth displacement and stress distribution. RESULTS As the miniscrew was located apically, the stress spread out to the root apex and the adjacent alveolar bone. At the 8-mm level of miniscrews, a bodily-like parallel retraction could be obtained with DJR. CONCLUSION In this study, the center of resistance of the six maxillary anterior teeth retracted by DJR with palatal miniscrews was estimated to be 12.2 mm apically from the incisal edge of the central incisor.
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Sung SJ, Jang GW, Chun YS, Moon YS. Effective en-masse retraction design with orthodontic mini-implant anchorage: A finite element analysis. Am J Orthod Dentofacial Orthop 2010; 137:648-57. [DOI: 10.1016/j.ajodo.2008.06.036] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/01/2008] [Accepted: 06/01/2008] [Indexed: 10/19/2022]
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Sia S, Shibazaki T, Koga Y, Yoshida N. Experimental determination of optimal force system required for control of anterior tooth movement in sliding mechanics. Am J Orthod Dentofacial Orthop 2009; 135:36-41. [PMID: 19121498 DOI: 10.1016/j.ajodo.2007.01.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 01/01/2007] [Accepted: 01/01/2007] [Indexed: 11/18/2022]
Affiliation(s)
- SheauSoon Sia
- Sia Orthodontic Dental Specialist Clinic, No. 5-1, Jalan Metro Perdana Barat 1, Taman Usahawan Kepong, 52100 Kuala Lumpur, Malaysia.
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Sung SJ, Kim IT, Kook YA, Chun YS, Kim SH, Mo SS. Finite-element analysis of the shift in center of resistance of the maxillary dentition in relation to alveolar bone loss. ACTA ACUST UNITED AC 2009. [DOI: 10.4041/kjod.2009.39.5.278] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sang-Jin Sung
- Associate Professor, Department of Orthodontics, University of Ulsan College of Medicine, Asan Medical Center, Korea
| | - In-Tai Kim
- Postgraduate Student, Graduate School of Clinical Dental Science, The Catholic University of Korea, Korea
| | - Yoon-Ah Kook
- Professor, Division of Orthodontics, Department of Dentistry, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Korea
| | - Youn-Sic Chun
- Professor, Division of Orthodontics, Department of Dentistry, School of Medicine, Ewha Womans University, Korea
| | - Seong-Hun Kim
- Assistant Professor, Division of Orthodontics, Department of Dentistry, College of Medicine, The Catholic University of Korea, Uijongbu St. Mary's Hospital, Korea
| | - Sung-Seo Mo
- Assistant Professor, Division of Orthodontics, Department of Dentistry, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, Korea
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Jeong GM, Sung SJ, Lee KJ, Chun YS, Mo SS. Finite-element investigation of the center of resistance of the maxillary dentition. ACTA ACUST UNITED AC 2009. [DOI: 10.4041/kjod.2009.39.2.83] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Gwang-Mo Jeong
- Graduate student, Graduate School of Clinical Dental Science, The Catholic University of Korea, Korea
| | - Sang-Jin Sung
- Associate Professor, Department of Orthodontics, University of Ulsan, Asan Medical Center, Korea
| | - Kee-Joon Lee
- Associate Professor, Department of Orthodontics, Yonsei University College of Dentistry, Korea
| | - Youn-Sic Chun
- Professior, Department of Orthodontics, Ehwa Womans University Mokdong Hospital, Korea
| | - Sung-Seo Mo
- Assistant Professor, Department of Orthodontics, The Catholic University of Korea, St. Mary's Hospital, Korea
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Sia SS, Koga Y, Yoshida N. Determining the Center of Resistance of Maxillary Anterior Teeth Subjected to Retraction Forces in Sliding Mechanics. Angle Orthod 2007; 77:999-1003. [DOI: 10.2319/112206-478] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 12/01/2006] [Indexed: 11/23/2022] Open
Abstract
Abstract
Objective: To determine the location of center of resistance and the relationship between height of retraction force on power arm (power-arm length) and movement of anterior teeth (degree of rotation) during sliding mechanics retraction.
Materials and Methods: Three human subjects with maxillary protrusion were selected for this study. Initial tooth displacements of maxillary right central incisor under sliding mechanics with various heights of retraction forces were measured in vivo using a two-point three-dimensional displacement magnetic sensor device. By calculating the angle of rotation from the displacements measured, the location of the center of resistance was determined.
Results: The results suggested that different heights of retraction forces could affect the direction of anterior tooth movement. The higher the retraction force was applied, the lower the degree of rotation (crown-lingual tipping) would be. The tooth rotation was in the opposite direction (from crown-lingual to crown-labial) if the height of the force was raised above the level of the center of resistance.
Conclusion: The location of the center of resistance of the maxillary central incisor was approximately 0.77 of the root length from the apex. During anterior tooth retraction with sliding mechanics, controlled crown-lingual tipping, bodily translation movement, and controlled crown-labial movement could be achieved by attaching a power-arm length that was lower, equivalent, or higher than the level of the center of resistance, respectively. The power-arm length could be the most easily modifiable clinical factor in determining the direction of anterior tooth movement during retraction with sliding mechanics.
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Affiliation(s)
- Sheau Soon Sia
- a PhD Graduate Student, Department of Orthodontics, School of Dentistry, Nagasaki University, Nagasaki City, Japan
| | - Yoshiyuki Koga
- b Assistant Professor, Department of Orthodontics, School of Dentistry, Nagasaki University, Nagasaki City, Japan
| | - Noriaki Yoshida
- c Professor and Department Chair, Department of Orthodontics, School of Dentistry, Nagasaki University, Nagasaki City, Japan
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Reimann S, Keilig L, Jäger A, Bourauel C. Biomechanical finite-element investigation of the position of the centre of resistance of the upper incisors. Eur J Orthod 2007; 29:219-24. [PMID: 17317864 DOI: 10.1093/ejo/cjl086] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The position of the centre of resistance (CR) is an essential parameter regarding the planning of orthodontic tooth movements. In the present investigation, the combined CR of the upper four incisors was determined numerically using the finite-element (FE) method. Based on a commercially available three-dimensional data set of a maxilla, including all 16 teeth, as well as known and earlier determined material parameters, FE models of the upper incisors and their surrounding tooth-supporting structures were generated. In the FE system, the model of the anterior segment was loaded with torques of 10 Nmm each at the lateral incisors. The FE model indicated that the individual incisors moved independently, although they were blocked with a steel wire of dimension 0.46 x 0.65 mm(2). The individual CRs were located at 5 mm distal and 9 and 12 mm apical to the centre of the lateral brackets. Thus, the classical view of a combined CR for the anterior segment was disproved and the planning of orthodontic tooth movements of the upper incisors should no longer be based on that concept.
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Affiliation(s)
- S Reimann
- Department of Orthodontics, University of Bonn, Germany
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Choy K, Kim KH, Burstone CJ. Initial changes of centres of rotation of the anterior segment in response to horizontal forces. Eur J Orthod 2006; 28:471-4. [PMID: 16916900 DOI: 10.1093/ejo/cjl023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study investigated the changes in the initial centres of rotation (Crot) of the upper six anterior teeth in response to a horizontal load. Six upper anterior teeth were extracted, splinted as a unit, and embedded in dental stone after the roots were uniformly coated with silicone. An aluminium fixture was bonded to the anterior segment and three linear variable differential transformers (LVDTs) were attached to measure the microdisplacement of the segment. A pulley and dead weight assembly were used to apply a 200 g occluso-gingivally varying horizontal force to the segment. The changes in the Crot for the anterior segment to the horizontal load were recorded. The results showed that the centre of resistance (Cres) of the upper anterior segment was located 14.5 mm apical and 9.5 mm distal from the incisal edge of the central incisors. A linear functional axis (a trace of the measured Crot) was recorded. The functional axis maintained an angle of 14.5 degrees to the vertical axis of the anterior segment passing through the Cres of the segment. The Crot constant, which determines the tipping sensitivity of the segment, was 23 mm(2). The results demonstrate that the upper anterior segment may be slightly intruded when a horizontal force is applied and is less prone to tipping than a single tooth.
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Affiliation(s)
- Kwangchul Choy
- Department of Orthodontics, Yongdong Severance Dental Hospital, Yonsei University, 146-92 Dogokdong, Seoul 135-270, Korea.
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Yoshida N, Jost-Brinkmann PG, Koga Y, Mimaki N, Kobayashi K. Experimental evaluation of initial tooth displacement, center of resistance, and center of rotation under the influence of an orthodontic force. Am J Orthod Dentofacial Orthop 2001; 120:190-7. [PMID: 11500662 DOI: 10.1067/mod.2001.115036] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to determine the location of the center of resistance and the center of rotation of the maxillary central incisors under the influence of a single simple force and to investigate related geometric parameters of the teeth and the surrounding periodontal tissues. By measuring the initial displacement of the central incisors with a magnetic sensing system, the location of the center of resistance and the centers of rotation associated with various forces were determined in 3 human subjects. The results show that the location of the center of resistance of the maxillary central incisor depends on the palatal bone level and is at approximately two-thirds of the palatal alveolar bone height, measured from the root apex. A greater moment-to-force ratio is needed for any controlled movement of the maxillary incisors during retraction in patients with reduced palatal alveolar bone height. This study suggests a method for estimating the location of the center of resistance of a tooth.
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Affiliation(s)
- N Yoshida
- Department of Orthodontics, Nagasaki University School of Dentistry, Japan.
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Matsui S, Caputo AA, Chaconas SJ, Kiyomura H. Center of resistance of anterior arch segment. Am J Orthod Dentofacial Orthop 2000; 118:171-8. [PMID: 10935957 DOI: 10.1067/mod.2000.103774] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is important to know the location of the center of resistance (CR) to control tooth movement. In this study, photoelastic techniques were used to determine the center of resistance. The photoelastic model included the anterior 4 maxillary teeth, which were interconnected firmly with 6 mm of space between lateral incisors and canines. Determination of the CR for the anterior arch segment was based on considerations of a wide variety of load conditions that generated the more uniform stresses in the supporting alveolar bone simulant. For the arch having the anterior 4 teeth connected, the CR was located within the mid-sagittal plane, 6-mm apical and 4-mm posterior to a line perpendicular to the occlusal plane from the labial alveolar crest of the central incisor.
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Affiliation(s)
- S Matsui
- Department of Orthodontics, School of Dentistry, Meikai University, Saitama, Japan.
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Güray E, Orhan M. "En masse" retraction of maxillary anterior teeth with anterior headgear. Am J Orthod Dentofacial Orthop 1997; 112:473-9. [PMID: 9387832 DOI: 10.1016/s0889-5406(97)70073-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the treatment of the first premolar extraction cases with certain techniques, incisor retraction is realized after canine distalization. In maximum anchorage cases, retraction of anterior segments require more posterior anchorage. This treatment concept is still valid, however, the difficult anchorage control is considered a major drawback. The purpose of this study is to introduce our technique for the "en masse" retraction of maxillary anterior teeth after first premolar extraction and discuss its effects. The technique consists of the application of extraoral traction on canines, followed by banding of maxillary anterior teeth, to form them as a mass. Advantages of our mechanics are as follows: (1) Anterior headgear may have the advantage of retracting anterior teeth with minimum strain on posterior anchorage. (2) The adjustability of the outer bow in relation to the premaxilla's center of resistance, provides effective desired movements. (3) Intrusion and torque control are achieved in the course of anterior segment retraction.
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Affiliation(s)
- E Güray
- Selçuk University, Faculty of Dentistry, Department of Orthodontics, Konya, Turkey
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