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Liu K, Chu G, Zhang C, Yang Y. Boundary of mandibular molar distalization in orthodontic treatment: A systematic review and meta-analysis. Orthod Craniofac Res 2024; 27:515-526. [PMID: 38462853 DOI: 10.1111/ocr.12778] [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: 10/19/2023] [Revised: 02/08/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024]
Abstract
To explore the mandibular retromolar space length (MRSL), initial root-inner cortex contact percentage (IRCCP), and the various factors that influence mandibular molar distalization. Searches were undertaken in PubMed, EMBASE, Web of Science, Cochrane Library, Scopus, and grey literature (Google Scholar and OpenGrey) for eligible cross-sectional observational studies measuring the MRSL and IRCCP in healthy adult patients. The risk of bias and evidence quality were evaluated using the Joanna Briggs Institute's checklist and GRADE framework. Thirteen studies involving 1169 patients were included for qualitative synthesis. Seven of these studies were eligible for quantitative analysis. Meta-analysis showed that the mean MRSL at the subfurcation-6 mm plane in Asian normodivergent cases was 3.78 mm (95% confidence interval [CI]: 2.81-4.35; I2 = 79.7%) for skeletal Class-I malocclusions, 3.02 mm (95% CI: 2.10-3.94; I2 = 62.5%) for Class-II, and 4.43 mm (95% CI: 3.14-5.73; I2 = 75.1%) for Class-III. The mean MRSL at the sub-cementoenamel junction (CEJ)-10 mm plane for Asian, Class-I, normodivergent cases was 3.28 mm (95% CI: 2.44-4.12; I2 = 68.9%). The mean IRCCP for Asian, Class-I, normodivergent cases was 27.2% (95% CI: 0.22-0.32; I2 = 0%). In Asian normodivergent cases, MRSL ranges from 3.28 to 4.43 mm with a 27.2% IRCCP for Class-I. Cone-beam computed tomography imaging is recommended for measuring the MRSL in the apex region particularly before molar distalization. Factors influencing MRSL and IRCCP include different races, skeletal patterns, facial types, and third-molar status.
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Affiliation(s)
- Keyuan Liu
- Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Guang Chu
- Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Chengfei Zhang
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Yanqi Yang
- Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
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Farret MM. Orthodontic biomechanics with intermaxillary elastics. Dental Press J Orthod 2023; 28:e23spe3. [PMID: 37493850 PMCID: PMC10365070 DOI: 10.1590/2177-6709.28.3.e23spe3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/29/2023] [Indexed: 07/27/2023] Open
Abstract
INTRODUCTION Intermaxillary elastics are orthodontic resources widely used in various malocclusions. Their main advantages are low cost, easy insertion and removal by patients, and application versatility. As main disadvantages, we can highlight the need for cooperation from patients and the side effects normally present in treatments with this resource. Knowledge of the biomechanics involved in the use of intermaxillary elastics is essential to take full advantage of the desired effects and avoid unwanted effects in their use. OBJECTIVE Therefore, the objective of this article is to describe the anchorage preparation, connection methods, time and force of use, and side effects involved in the use of intermaxillary elastics for the treatment of anteroposterior, vertical and transverse problems. For that, clinical cases and biomechanics schemes will be presented, in which all these details will be described.
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Affiliation(s)
- Marcel Marchiori Farret
- Centro de Estudos Odontológicos Meridional (CEOM), Especialização em Ortodontia (Passo Fundo/RS, Brazil)
- Private practice (Santa Maria/RS, Brazil)
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Heo S, Park JH, Lee MY, Kim JS, Jung SP, Chae JM. Maxillary incisor position-based orthodontic treatment with miniscrews. Semin Orthod 2022. [DOI: 10.1053/j.sodo.2022.10.011] [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: 11/06/2022]
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Fan Z, Zhang Q, Jiang Y, Qin Q, Huang S, Guo J. Mandibular retromolar space in adults with different sagittal skeletal patterns. Angle Orthod 2022; 92:483764. [PMID: 35849081 PMCID: PMC9374353 DOI: 10.2319/112021-854.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/01/2022] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To analyze the mandibular retromolar space among normal-divergent adult patients with different sagittal skeletal patterns by cone-beam computed tomography (CBCT). MATERIALS AND METHODS CBCTs of a total of 120 normal-divergent adult patients were investigated. Patients were categorized into the following three groups according to their ANB angle: skeletal Class I (48 patients), skeletal Class II (36 patients), and skeletal Class III (36 patients). Four different planes parallel to the mandibular occlusal plane were used to measure the retromolar space. The retromolar space was measured by two reference lines and then compared between different sagittal skeletal patterns groups. The incidence of root contact with the inner lingual cortex was compared among the three groups. RESULTS The retromolar space of the Class III patients was significantly larger than that of Class I patients and Class II patients. Compared with Class I and Class III patients, Class II patients had a smaller retromolar space and higher incidence of contact with the inner cortex of the mandible. CONCLUSIONS Class III patients had a larger retromolar space than Class I patients and Class II patients in four different planes. The mandibular retromolar space should be evaluated by CBCT in patients who need mandibular molar distalization.
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Choi DS, Lee DH, Jang I, Cha BK. Camouflage treatment by backward rotation of the mandible for a severe skeletal Class III malocclusion with aplastic anemia: A case report. Korean J Orthod 2022; 52:362-371. [PMID: 36148643 PMCID: PMC9512624 DOI: 10.4041/kjod22.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/31/2022] [Accepted: 05/04/2022] [Indexed: 11/10/2022] Open
Abstract
Orthognathic surgery is the primary treatment option for severe skeletal discrepancy. However, orthodontic camouflage should be considered as an alternative treatment option, considering the risks of surgery. A 19.5-year-old man presented with a severe prognathic mandible with a Class III molar relationship and an anterior crossbite. Orthognathic surgery could be considered because of his severe skeletal discrepancy and mandibular prognathism. However, the anesthetist for orthognathic surgery did not recommend surgery under general anesthesia because of risk factors associated with the patient's aplastic anemia, including bleeding and infections. Thus, a camouflage treatment to promote backward rotation of the mandible via orthodontic extrusion of the posterior teeth was planned. An anterior bite plate, intermaxillary elastics, and fixed orthodontic appliances were used to extrude the posterior teeth and to align the dentition. After 17 months of nonsurgical orthodontic treatment, normal occlusion was achieved, and the facial profile was dramatically improved. This case report describes the dentoskeletal and soft-tissue effects of mandibular rotation and its long-term stability.
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Affiliation(s)
- Dong-Soon Choi
- Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea
| | - Dong-Hyun Lee
- Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea
| | - Insan Jang
- Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea
| | - Bong-Kuen Cha
- Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea
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Long-Term CBCT Evaluation of Mandibular Third Molar Changes after Distalization in Adolescents. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Introduction: This study aimed to evaluate mandibular molar changes after distalization using Class III elastics and modified C-palatal plates (MCPPs) in the maxilla and to use CBCT to specifically analyze the third-molar position after long-term retention in adolescents. Methods: The sample consisted of 65 mandibular third molars from 35 subjects, divided into two groups. Twenty-six of the third molars were from fourteen adolescent patients with Class I bimaxillary protrusion (mean age, 12.8 years) who had undergone bilateral maxillary distalization using an MCPP and mandibular distalization with Class III elastics with non-extraction treatment. For the control group, 39 third molars from 21 Class I normal-occlusion subjects were used. In the treated group, CBCT images were taken before distalization (T1), after molar distalization (T2), and at a long-term observation point (6.1 ± 2.7 years) (T3). Repeated measures ANOVA and a post hoc test with Bonferroni correction were used to analyze significant differences in the positions at the three points in time. Results: There were 2.3 and 1.7 mm of distal movement at the crown of the mandibular first and second molars, with distal tipping of 5.2° and 5.3°, respectively, and 3.0° of distal tipping of the third molars. Comparing the treated group with the control group at T3, there was a significant change in the angulation of the third molars (p < 0.001). In the long-term, the third molars from the treated group showed a downward and buccal position after distalization. Conclusions: In the long term, the developing mandibular third molar buds had downward and buccal positional changes after total arch distalization. These findings suggest the need for clinicians to consider the possibility of the impaction of developing third molars after mandibular total arch distalization in adolescents.
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Digital Photoelastic Analysis of TAD-Supported Maxillary Arch Distalization. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12041949] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective of this study was to determine whether the distribution of compressional and tensional stress around tooth roots is influenced by the position of a temporary anchorage device and the length of the retraction hook during the distalization of the maxillary dentition. A photoelastic orthodontic model was made of photoelastic epoxy resin. Six combinations of three retraction hook lengths and two posterior Temporary skeletal anchorage devices (TAD) positions were established. Stress was applied through an elastic chain for each of the combinations. Digital photoelastic stress analysis measured the compression, tensional stress, and direction around the tooth root. Using this novel photoelastic model, we found that the distribution of compressional and tensional stress during the retraction of the maxillary dentition was significantly influenced by the position of the TAD and the length of the retraction hook.
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Park JH, Oh JY, Lee SY, Kook YA, Han SH. Correction of an adult Class III malocclusion through regaining of orthodontic space and an implant restoration. J ESTHET RESTOR DENT 2022; 34:297-308. [PMID: 35080110 DOI: 10.1111/jerd.12870] [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: 10/15/2021] [Revised: 12/18/2021] [Accepted: 12/28/2021] [Indexed: 11/29/2022]
Abstract
This case report describes the interdisciplinary treatment of a 23-year-old female with Class III malocclusion and a missing maxillary left second premolar. Treatment alternatives were discussed, and the selected treatment plan was presented to illustrate a way to gain space for the premolar implant restoration and correct Class III relationship through maxillary molar retraction followed by maxillary total arch protraction with a palatal temporary skeletal anchorage device. Esthetic anterior alignment and functional occlusal rehabilitation was achieved, and facial balance was maintained at the end of treatment. CLINICAL SIGNIFICANCE: Implant restoration in conjunction with regaining orthodontic space by a team of multidisciplinary dental specialists presents an effective treatment solution to permanent tooth agenesis. Class III malocclusion can be treated with a combination of maxillary protraction and mandibular retraction using temporary skeletal anchorage devices. The versatility of modified palatal C-plates presents greater clinical application when related side effects are controlled with solid understanding of their biomechanics.
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Affiliation(s)
- Jae Hyun Park
- Orthodontic Program, Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, Arizona, USA.,Graduate School of Dentistry, Kyung Hee University, Seoul, South Korea
| | - Ji Young Oh
- Department of Orthodontics, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, South Korea
| | - Su Young Lee
- Department of Prosthodontics, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, South Korea
| | - Yoon-Ah Kook
- Department of Orthodontics, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, South Korea
| | - Seong Ho Han
- Division of Orthodontics, Department of Dentistry, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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Fukawa R, Moon W, Deguchi T, Aga M. Posterior crossbite with mandibular asymmetry treated with lingual appliances, maxillary skeletal expanders, and alveolar bone miniscrews. Am J Orthod Dentofacial Orthop 2021; 161:293-312.e1. [PMID: 34876313 DOI: 10.1016/j.ajodo.2021.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 11/30/2022]
Abstract
Posterior crossbite and mandibular asymmetry affect esthetics and function. We report treatment of 3 patients with posterior crossbite with mandibular asymmetry but different anteroposterior and vertical characteristics. Treatment methods included maxillary skeletal expander, miniscrews, and lingual appliances. The results show that by using these appliances, ideal transverse, anteroposterior, and vertical control is possible in patients who have concerns about the esthetics of buccal appliances. Lingual appliances can provide satisfying results when combined with a maxillary skeletal expander and miniscrews in complex patients.
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Affiliation(s)
| | - Won Moon
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea; The Forsyth Institute, Harvard School of Dental Medicine Affiliate, Cambridge, Mass
| | - Toru Deguchi
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio.
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Biomechanical analysis for total mesialization of the maxillary dentition: A finite element study. Am J Orthod Dentofacial Orthop 2021; 159:790-798. [DOI: 10.1016/j.ajodo.2020.02.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/01/2020] [Accepted: 02/01/2020] [Indexed: 12/26/2022]
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Park JH, Heo S, Tai K, Kojima Y, Kook YA, Chae JM. Biomechanical considerations for total distalization of the mandibular dentition in the treatment of Class III malocclusion. Semin Orthod 2020. [DOI: 10.1053/j.sodo.2020.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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CBCT Analysis of Changes in Dental Occlusion and Temporomandibular Joints before and after MEAW Orthotherapy in Patients with Nonlow Angle of Skeletal Class III. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7238263. [PMID: 32149128 PMCID: PMC7053462 DOI: 10.1155/2020/7238263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/02/2020] [Indexed: 11/29/2022]
Abstract
This study focus on the changes of the position and morphology of jaw and condyle after MEAW (the multiloop edgewise arch wire) treatment in adults with a nonlow angle (mean angle or high angle SN − MP > 27°) of skeletal class III (mild to moderate skeletal classs III means −5° < ANB < 0°) malocclusions measured by CBCT (cone beam computed tomography). Twenty adult patients (aged 17-26) with a nonlow angle of skeletal class III malocclusions were selected in this study taken orthodontic treatment by MEAW. CBCT was taken before and after the treatment to analyze the changes of the jaw and condyle. After treatment, the angle of L7-MP decreased 12.2°, L6-MP decreased 10.5°, L1-MP decreased 8.8° (P < 0.001 for each) and U1-SN increased (P < 0.05). There was no significant changes between anterior and posterior APDI index and between anterior and posterior spaces of the TMJ (temporomandibular joint) (P > 0.05). The linear ratio of the TMJ was the LR > 12 before treatment, while it was −12 < LR < 12 after treatment; however, there was no statistically significant difference between them (P > 0.05). There was also no significant change in anterior and posterior position and morphology of the condyle within the joint fossa after the treatment by MEAW in this study. MEAW technology in correcting the class III with nonlow angle patients mainly relies on the compensation of distally and posterior mandibular teeth, rather than the mandible and condyle moving backward to establish a neutral occlusal. This study was approved by the institutional ethics committee of the Second Hospital of Tianjin Medical University (No. KYJJ2013002).
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Posterior Available Space for Uprighting Horizontally Impacted Mandibular Second Molars Using Orthodontic Microimplant Anchorage. J Clin Pediatr Dent 2019; 43:56-63. [PMID: 30289367 DOI: 10.17796/1053-4625-43.1.11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Treatment of horizontally and deeply impacted mandibular molars is challenging for both orthodontists and oral surgeons because of the limited access and anchorage control. We report on two patients who had horizontally and mesially impacted mandibular second molars (MM2s). Both patients were treated by a surgical orthodontic approach, and the crowns of the impacted teeth were brought into the arches by closed forced eruption. Mesially impacted MM2s were uprighted with orthodontic microimplants, inserted in the retromolar area, and then moved into their ideal position. The first patient was in an active growing stage, while the second patient was beyond the active growing stage. Therefore posterior available space (PAS) should be analyzed before treatment of impacted MM2s to prevent periodontal problems after uprighting of impacted teeth. If PAS is not enough for uprighting impacted MM2s, alternative treatment should be considered based on the stage of growth.
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de Frutos-Valle L, Martin C, Alarcon JA, Palma-Fernandez JC, Iglesias-Linares A. Subclustering in Skeletal Class III Phenotypes of Different Ethnic Origins: A Systematic Review. J Evid Based Dent Pract 2018; 19:34-52. [PMID: 30926101 DOI: 10.1016/j.jebdp.2018.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/22/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
OBJECTIVE We aimed to systematically review articles investigating the efficiency of the clustering of skeletal class III malocclusion phenotypic subtypes of different ethnic origins as a diagnostic tool. METHODS The review protocol was structured in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and registered in Prospero (CRD42016053865). A survey of articles published up to March 2018 investigating the identification of different subgroups of skeletal class III malocclusion via cluster analysis was performed using 11 electronic databases. Any type of study design that addressed the classification of subclusters of class III malocclusion was considered. The Newcastle-Ottawa scale for cohort and cross-sectional (modified) studies was used for quality assessment. RESULTS The final selection included 7 studies that met all the criteria for eligibility (% overall agreement 0.889, free marginal kappa 0.778). All studies identified at least 3 different types of class III clusters (ranging from 3 to 14 clusters; the total variation of the prevalence of each cluster ranged from 0.2% to 36.0%). The main shared variables used to describe the more prevalent clusters in the studies included were vertical measurements (Ar-Go-Me: 117.51°-135.8°); sagittal measurements: maxilla (SNA: 75.3°-82.95°), mandible (SNB: 77.03°-85.0°). With regard to ethnicity, a mean number of 8.5 and 3.5 clusters of class III were retrieved for Asian and Caucasian population, respectively. CONCLUSIONS The total number of clusters identified varied from 3 to 14 to explain all the variability in the phenotype class III malocclusions. Although each extreme may be too simple or complex to facilitate an exhaustive but useful classification for clinical use, a classification system including 4 to 7 clusters may prove to be efficient for clinical use in conjunction with complete and meticulous subgrouping. CLINICAL SIGNIFICANCE The identification and description of a subclustering classification system may constitute an additional step toward more precise orthodontic/orthopedic diagnosis and treatment of skeletal class III malocclusion.
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Affiliation(s)
| | - Conchita Martin
- Section of Orthodontics, Faculty of Odontology, Complutense University, Madrid, Spain; BIOCRAN (Craniofacial Biology) Research Group, Complutense University, Madrid, Spain.
| | - Jose Antonio Alarcon
- BIOCRAN (Craniofacial Biology) Research Group, Complutense University, Madrid, Spain; Faculty of Odontology, University of Granada, Campus Universitario de Cartuja, Granada, Spain
| | | | - Alejandro Iglesias-Linares
- Section of Orthodontics, Faculty of Odontology, Complutense University, Madrid, Spain; BIOCRAN (Craniofacial Biology) Research Group, Complutense University, Madrid, Spain
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Abstract
INTRODUCTION The smile poses a challenge in the treatment of class III. Untreated, the class III patient presents excessive maxillary torque and a predominant display of the mandibular incisors, a sign that becomes more visible with age. Functional orthopedics restores the aesthetic appearance of the smile by maxillary protraction (sometimes temporarily because 20% of cases will still need surgery). Depending on the initial severity of the case (-4.5 mm AoBo would be the threshold value), the options are compensation or surgical correction. In both cases, the profile is improved but without normalising the cephalometric values. In recent years, the number of published cases treated by compensations (often using skeletal anchorage) has multiplied with broader indications, particularly for Asian patients in whom Le Fort I surgery gives questionable aesthetic results. Attention must be focused on the occlusal plane rotation which alters the smile by displaying the mandibular incisors. Nevertheless, surgery can handle the most severe cases with a greater degree of improvement. AIM The aim of this article is to determine the cephalometric cut-off values for an acceptable smile in Class III patients. MATERIALS AND METHODS We performed a search on Pubmed using the following keywords: Class III, anterior cross bite, smile, camouflage, orthognathic surgery; then secondarily, using references supplied by the articles found. We then analysed the data. RESULTS The ortho-surgical protocol associated with extractions of maxillary first premolars appears to be the way to obtain the best results in terms of the smile (versus surgery without extractions and versus orthodontic compensations) because it is, in fact, the only way to restore the normal position and torque of the maxillary incisors, thus increasing their display during smiling.
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Affiliation(s)
- Laure De Launay
- Département d'Orthopédie Dento-Faciale, Faculté d'Odontologie, rue Guillaume Paradin, 69372 Lyon cedex 08, France
| | - Sarah Gebeile-Chauty
- Département d'Orthopédie Dento-Faciale, Faculté d'Odontologie, rue Guillaume Paradin, 69372 Lyon cedex 08, France
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Liou EJW, Wang YC. Orthodontic Clockwise Rotation of Maxillomandibular Complex for Improving Facial Profile in Late Teenagers with Class III Malocclusion: A Preliminary Report. APOS TRENDS IN ORTHODONTICS 2018. [DOI: 10.4103/apos.apos_9_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objective
Orthodontic camouflage treatments improve occlusion but might worsen facial profile in patients with Class III malocclusion. It has been reported that surgical clockwise rotation of maxillomandibular complex (MMc) improves facial profile by reducing chin prominence and chin throat length in patients with Class III malocclusion. The purpose of this report was to illustrate two orthodontic techniques for clockwise rotation of the MMc in late teenagers with Class III malocclusion and preliminarily evaluate their clinical effects.
Patients and Methods
Six patients in late teenage with Class III malocclusion were included in this preliminary report. Bite raisers were first placed on the upper molars to open the bite and clockwise rotate the mandible. Intermaxillary elastics were then applied vertically between the upper and lower dentitions in 3 patients for bimaxillary extrusion (Technique-1) or between the upper dentition and the lower temporary anchorage devices (TADs) in another 3 patients (Technique-2) for upper dentition extrusion and closure of the anterior open bite. The three-dimensional cone-beam computed tomography images taken before and after orthodontic treatment were superimposed to evaluate the treatment effects of MMc clockwise rotation for both techniques.
Results
The Technique-1 extruded the upper and lower dentitions, rotated the mandible clockwise 2.01°, moved chin down 2.98 mm, and back −1.64 mm, although the mandible grew 2.47 mm during the treatment period. The Technique-2 extruded the upper dentition, rotated the mandible clockwise 0.90°, moved chin down 1.78 mm, but slightly forward 0.47 mm due to the mandible grew 2.50 mm and lower dentition was not extruded.
Conclusions
The orthodontic clockwise rotation of MMc is an effective technique for orthognathic camouflage. The applications of bite raisers and bimaxillary dentition extrusion could be more effective than single dentition extrusion with TADs in the mandible for clockwise rotation of MMc and improvement of occlusion and facial profile in late teenagers with Class III malocclusion. However, the comprehensive clinical effects and long-term stability need further clinical studies.
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Affiliation(s)
- Eric J. W. Liou
- Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, Taipei, Taiwan
| | - Yu-Chi Wang
- Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, Taipei, Taiwan
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Janson G, Maranhão OBV. Compensatory Class III malocclusion treatment associated with mandibular canine extractions. Dental Press J Orthod 2018; 22:86-98. [PMID: 29364384 PMCID: PMC5784821 DOI: 10.1590/2177-6709.22.6.086-098.bbo] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 09/21/2017] [Indexed: 11/22/2022] Open
Abstract
Skeletal Class III malocclusions are ideally treated with orthodontic-surgical approaches. However, if there are no significant soft tissue implications and the patient does not want to undergo orthognatic surgery, other treatment options may be considered. The current case report describes a compensatory alternative for Class III malocclusion treatment, by means of mandibular canine extractions. This treatment alternative provided facial profile and occlusal improvement, which remains stable seven years posttreatment.
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Affiliation(s)
- Guilherme Janson
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Ortodontia (Bauru/SP, Brasil)
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