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Wang TH, Chen YF, Chen YA, Yao CF, Xi T, Liao YF, Chen YR. Site and severity of facial asymmetry after bimaxillary surgery for class III deformity: a case-control study. Clin Oral Investig 2024; 28:334. [PMID: 38780816 DOI: 10.1007/s00784-024-05729-9] [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: 10/12/2023] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
OBJECTIVES The study aimed (1) to evaluate the site and severity of facial asymmetry in Class III patients before and after bimaxillary surgery, and (2) to identify the influence of initial severity and positional jaw asymmetry on residual facial asymmetry. MATERIALS AND METHODS Preoperative and postoperative cone-beam computed tomography of 65 patients with Class III facial asymmetry who underwent bimaxillary surgery were evaluated. Five midline and 14 paramedian facial soft tissue landmarks were identified to assess facial asymmetry. The outcomes were compared to a control group consisting of 30 age- and gender-matched Class I subjects. The postoperative positional jaw asymmetry (i.e., shift, roll, yaw) of each osteotomy segment (maxilla, mandible, chin, ramus) was also measured. RESULTS Before surgery, the asymmetry was more severe at the chin, middle and lower contour. Bimaxillary surgery effectively corrected facial asymmetry, particularly in achieving normalization of chin deviation. However, significant asymmetry persisted postoperatively in the middle and lower contour (p < 0.001 and p < 0.01, respectively), which was affected by the positional ramus asymmetry in the roll and shift. CONCLUSIONS Deviation of the chin, middle and lower contour contributed significantly to overall facial asymmetry in Class III asymmetry. Despite normalization of the chin deviation after bimaxillary surgery, asymmetry persisted at the middle and lower contour, primarily as the result of insufficient correction of the positional ramus asymmetry. CLINICAL RELEVANCE Understanding the residual asymmetry after bimaxillary surgery is important for minimizing deviation and optimizing the surgical planning for its correction.
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Affiliation(s)
- Tzu-Hsin Wang
- Graduate Institute of Dental and Craniofacial Science, Chang Gung University, Taoyuan, Taiwan
- Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, No. 123, Dinghu Road, Guishan District, Taoyuen City, 333, Taiwan
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Yun-Fang Chen
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, Taipei, Taiwan
| | - Ying-An Chen
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chuan-Fong Yao
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Tong Xi
- Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Yu-Fang Liao
- Graduate Institute of Dental and Craniofacial Science, Chang Gung University, Taoyuan, Taiwan.
- Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, No. 123, Dinghu Road, Guishan District, Taoyuen City, 333, Taiwan.
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan.
| | - Yu-Ray Chen
- Graduate Institute of Dental and Craniofacial Science, Chang Gung University, Taoyuan, Taiwan
- Craniofacial Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
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Lee J, Kim D, Xu X, Kuang T, Gateno J, Yan P. Predicting optimal patient-specific postoperative facial landmarks for patients with craniomaxillofacial deformities. Int J Oral Maxillofac Surg 2024:S0901-5027(24)00149-8. [PMID: 38782663 DOI: 10.1016/j.ijom.2024.05.004] [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: 12/13/2023] [Revised: 05/07/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
Orthognathic surgery primarily corrects skeletal anomalies and malocclusion to enhance facial aesthetics, aiming for an improved facial appearance. However, this traditional skeletal-driven approach may result in undesirable residual asymmetry. To address this issue, a soft tissue-driven planning methodology has been proposed. This technique estimates bone movements based on the envisioned optimal facial appearance, thereby enhancing surgical accuracy and effectiveness. This study investigates the initial implementation phase of the soft tissue-driven approach, simulating the patient's ideal appearance by realigning distorted facial landmarks to an ideal state. The algorithm employs symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are essential in orthognathic surgery for facial aesthetics. It also incorporates regularization to preserve the patient's facial characteristics. Validation through retrospective analysis of preoperative patients and normal subjects demonstrates this method's efficacy in achieving facial symmetry, particularly in the lower face, and promoting a natural, harmonious contour. Adhering to soft tissue-driven principles, this novel approach shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.
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Affiliation(s)
- J Lee
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - D Kim
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, USA.
| | - X Xu
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - T Kuang
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, USA
| | - J Gateno
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, USA; Department of Surgery (Oral and Maxillofacial Surgery), Weill Medical College, Cornell University, New York, USA
| | - P Yan
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
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Ajmera DH, Singh P, Leung YY, Khambay BS, Gu M. Establishment of the mid-sagittal reference plane for three-dimensional assessment of facial asymmetry: a systematic review : Establishment of the mid-sagittal reference plane: a systematic review. Clin Oral Investig 2024; 28:242. [PMID: 38575839 PMCID: PMC10995046 DOI: 10.1007/s00784-024-05620-7] [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: 05/09/2022] [Accepted: 03/13/2024] [Indexed: 04/06/2024]
Abstract
OBJECTIVE To systematically review the literature for mid-sagittal plane establishment approaches to identify the most effective method for constructing the mid-sagittal plane for the evaluation of facial asymmetry. MATERIALS AND METHODS Six electronic databases (PubMed, Medline (via Ovid), EMBASE (via Ovid), Cochrane Library, Web of Science, and Scopus) and grey literature were searched for the studies that computed the mid-sagittal reference plane three-dimensionally, using a combination of MeSH terms and keywords. The methodological quality and the level of evidence for the included studies were analyzed using QUADAS-2 and GRADE, respectively. RESULTS The preliminary search yielded 6746 records, of which 42 articles that met the predefined inclusion criteria were included in the final analysis. All the included articles reported the construction of the mid-sagittal reference plane (MSP) using varied methods. The risk of bias and concerns regarding the applicability of the included studies were judged to be 'low'. The level of evidence was determined to be 'low' for the effectiveness of the technique and 'moderate' for the ease of clinical applicability. CONCLUSION Despite methodological heterogeneity, this review substantiates the comparable efficacy of cephalometric and morphometric MSP construction methods. A fully automated morphometric MSP holds promise as a viable option for routine clinical use. Nevertheless, future prospective studies with an emphasis on the impact, accuracy, and clinical applicability of MSP construction techniques in cases of facial asymmetry are required. CLINICAL RELEVANCE The present review will assist clinicians in selecting the most suitable method for MSP construction, leading to improved treatment planning and ultimately more favorable treatment outcomes.
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Affiliation(s)
- Deepal Haresh Ajmera
- Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Pradeep Singh
- Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Yiu Yan Leung
- Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Balvinder S Khambay
- Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
- Orthodontics Department, School of Dentistry, University of Birmingham, Birmingham, UK.
- Discipline of Orthodontics, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China.
| | - Min Gu
- Discipline of Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
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Lee J, Kim D, Xu X, Kuang T, Gateno J, Yan P. Predicting Optimal Patient-Specific Postoperative Facial Landmarks for Patients with Craniomaxillofacial Deformities. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.13.23299919. [PMID: 38187692 PMCID: PMC10767768 DOI: 10.1101/2023.12.13.23299919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Orthognathic surgery traditionally focuses on correcting skeletal abnormalities and malocclusion, with the expectation that an optimal facial appearance will naturally follow. However, this skeletal-driven approach can lead to undesirable facial aesthetics and residual asymmetry. To address these issues, a soft-tissue-driven planning method has been proposed. This innovative method bases bone movement estimates on the targeted ideal facial appearance, thus increasing the surgical plan's accuracy and effectiveness. This study explores the initial phase of implementing a soft-tissue-driven approach, simulating the patient's optimal facial look by repositioning deformed facial landmarks to an ideal state. The algorithm incorporates symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are integral to facial aesthetics in orthognathic surgery. It also includes regularization to preserve the patient's original facial characteristics. Validated using retrospective analysis of data from both preoperative patients and normal subjects, this approach effectively achieves not only facial symmetry, particularly in the lower face, but also a more natural and normalized facial form. This novel approach, aligning with soft-tissue-driven planning principles, shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.
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Affiliation(s)
- Jungwook Lee
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Daeseung Kim
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Xuanang Xu
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Tianshu Kuang
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Jaime Gateno
- Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Surgery (Oral and Maxillofacial Surgery), Weill Medical College, Cornell University, New York, NY, 10021, USA
| | - Pingkun Yan
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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Ajmera DH, Zhang C, Ng JHH, Hsung RTC, Lam WYH, Wang W, Leung YY, Khambay BS, Gu M. Three-dimensional assessment of facial asymmetry in class III subjects, part 2: evaluating asymmetry index and asymmetry scores. Clin Oral Investig 2023; 27:5813-5826. [PMID: 37615775 PMCID: PMC10560190 DOI: 10.1007/s00784-023-05193-x] [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: 05/27/2022] [Accepted: 07/28/2023] [Indexed: 08/25/2023]
Abstract
OBJECTIVES To evaluate the outcomes of corrective surgical treatment for craniofacial asymmetry using four different methods with the aim of developing the best technique for craniofacial asymmetry assessment. MATERIALS AND METHODS CBCT images of twenty-one class III subjects with surgically corrected craniofacial asymmetry and twenty-one matched controls were analyzed. Twenty-seven hard tissue landmarks were used to quantify asymmetry using the following methodologies: the asymmetry index (AI), asymmetry scores based on the clinically derived midline (CM), Procrustes analysis (PA), and modified Procrustes analysis (MPA). RESULTS Modified Procrustes analysis successfully identified pre-operative asymmetry and revealed severe asymmetry at the mandibular regions compared to controls, which was comparable to the asymmetry index and clinically derived midline methods, while Procrustes analysis masked the asymmetric characteristics. Likewise, when comparing the post-surgical outcomes, modified Procrustes analysis not only efficiently determined the changes evidencing decrease in facial asymmetry but also revealed significant residual asymmetry in the mandible, which was congruent with the asymmetry index and clinically derived midline methods but contradictory to the results shown by Procrustes analysis. CONCLUSIONS In terms of quantifying cranio-facial asymmetry, modified Procrustes analysis has evidenced to produce promising results that were comparable to the asymmetry index and the clinically derived midline, making it a more viable option for craniofacial asymmetry assessment. CLINICAL RELEVANCE Modified Procrustes analysis is proficient in evaluating cranio-facial asymmetry with more valid clinical representation and has potential applications in assessing asymmetry in a wide spectrum of patients, including syndromic patients.
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Affiliation(s)
- Deepal Haresh Ajmera
- Discipline of Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China
| | - Congyi Zhang
- Department of Computer Science, The University of Hong Kong, Hong Kong SAR, China
| | - Janson Hoi Hei Ng
- Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China
| | - Richard Tai-Chiu Hsung
- Department of Computer Science, Hong Kong Chu Hai College, Hong Kong SAR, China
- Division of Oral and Maxillofacial Surgery, Faculty, of Dentistry, the University of Hong Kong, Hong Kong SAR, China
| | - Walter Yu Hang Lam
- Discipline of Prosthodontics, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China
| | - Wenping Wang
- Department of Computer Science, The University of Hong Kong, Hong Kong SAR, China
- Texas A&M University, College Station, TX, USA
| | - Yiu Yan Leung
- Division of Oral and Maxillofacial Surgery, Faculty, of Dentistry, the University of Hong Kong, Hong Kong SAR, China
| | - Balvinder S Khambay
- Discipline of Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China
- Institute of Clinical Sciences, College of Medical and Dental Sciences, The School of Dentistry, University of Birmingham, Birmingham, UK
| | - Min Gu
- Discipline of Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, the University of Hong Kong, Hong Kong SAR, China.
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Zhao J, Xu Y, Wang J, Lu Z, Qi K. 3-dimensional analysis of hard- and soft-tissue symmetry in a Chinese population. BMC Oral Health 2023; 23:432. [PMID: 37386472 PMCID: PMC10308641 DOI: 10.1186/s12903-023-03163-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/22/2023] [Indexed: 07/01/2023] Open
Abstract
BACKGROUND Facial symmetry severely affects appearance and function. Large numbers of patients seek orthodontic treatment to improve facial symmetry. However, the correlation between hard- and soft-tissue symmetry is still unclear. Our aim was to investigate the hard- and soft-tissue symmetry in subjects with different levels of menton deviation and sagittal skeletal classes with 3D digital analysis and to investigate the relationship between the entire and individual hard- and soft-tissues. METHODS A total of 270 adults (135 males and 135 females) consisting of 45 subjects of each sex in each sagittal skeletal classification group. All subjects were further classified into relative symmetry (RS), moderate asymmetry (MA) and severe asymmetry (SA) groups based on the degree of menton deviation from the mid-sagittal plane (MSP). The 3D images were segmented into anatomical structures and mirrored across the MSP after establishing a coordinate system. Original and mirrored images were registered by a best-fit algorithm, and the corresponding root mean square (RMS) values and colormap were obtained. The Mann‒Whitney U test and Spearman correlation were conducted for statistical analysis. RESULTS The RMS increased with greater deviations with regard to the deviation of the menton in most of anatomical structures. Asymmetry was represented in the same way regardless of sagittal skeletal pattern. The soft-tissue asymmetry had a significant correlation with dentition in the RS group (0.409), while in the SA group, it was related to the ramus (0.526) and corpus (0.417) in males and was related to the ramus in the MA (0.332) and SA (0.359) groups in females. CONCLUSIONS The mirroring method combining CBCT and 3dMD provides a new approach for symmetry analysis. Asymmetry might not be influenced by sagittal skeletal patterns. Soft-tissue asymmetry might be reduced by improving the dentition in individuals with RS group, while among those with MA or SA, whose menton deviation was larger than 2 mm, orthognathic treatment should be considered.
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Affiliation(s)
- Jiamin Zhao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
- Department of Orthodontics, Stomatological Hospital of Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
| | - Yifei Xu
- Department of Oral Anatomy and Physiology and TMD, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Jinxiu Wang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
- Department of Orthodontics, Stomatological Hospital of Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
| | - Zhen Lu
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
- Department of Orthodontics, Stomatological Hospital of Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China
| | - Kun Qi
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China.
- Department of Orthodontics, Stomatological Hospital of Xi'an Jiaotong University, 98 XiWu Road, 710004, Xi'an, Shaanxi, P.R. China.
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Hard and Soft Tissue Asymmetry in Patients with Skeletal Class III Malocclusion: A Cone-Beam Computed Tomography Study. Diagnostics (Basel) 2023; 13:diagnostics13050869. [PMID: 36900013 PMCID: PMC10000951 DOI: 10.3390/diagnostics13050869] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 02/16/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023] Open
Abstract
This study aims to investigate hard and soft tissue asymmetry in skeletal Class III patients to elucidate how soft tissue thickness alters overall asymmetry and whether menton deviation is correlated with bilateral differences in hard and soft tissue prominence and soft tissue thickness. The cone-beam computed tomography data of 50 skeletal Class III adults were divided based on menton deviation into symmetric (n = 25; deviation ≤ 2.0 mm) and asymmetric (n = 25; deviation > 2.0 mm) groups. Forty-four corresponding hard and soft tissue points were identified. Bilateral hard and soft tissue prominence and soft tissue thickness were compared using paired t-tests. The correlations between bilateral differences in these variables and menton deviation were examined using Pearson's correlation analysis. In the symmetric group, no significant bilateral differences in soft and hard tissue prominence and soft tissue thickness were observed. In the asymmetric group, both hard and soft tissue prominence were significantly greater on the deviated side than the non-deviated side at most of the points; however, no significant differences in soft tissue thickness were detected except at point 9 (ST9/ST'9, p = 0.011). The difference of hard and soft tissue prominence at point 8 (H8/H'8 and S8/S'8) was positively correlated with menton deviation, whereas the soft tissue thickness at point 5 (ST5/ST'5) and point 9 (ST9/ST'9) was negatively correlated with menton deviation (p = 0.05). Soft tissue thickness does not affect overall asymmetry in the presence of underlying hard tissue asymmetry. Soft tissue thickness at the centre of the ramus may be correlated with the degree of menton deviation in patients with asymmetry; however, this correlation needs to be confirmed by further studies.
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Kim HJ, Noh HK, Park HS. Use of a novel body mandibular plane (mental foramen-protuberance menti) in analyzing mandibular asymmetry compared with conventional border mandibular plane. Angle Orthod 2023; 93:490379. [PMID: 36689739 PMCID: PMC9933560 DOI: 10.2319/072522-513.1] [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: 07/01/2022] [Accepted: 12/01/2022] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVES To compare a novel body mandibular horizontal plane (mental foramen-protuberance menti; Body-MHP) with the conventional border mandibular horizontal plane (gonion-menton [Me]; Border-MHP) to assess mandibular body inclination and dental compensation of skeletal Class III patients with and without facial asymmetry. MATERIALS AND METHODS Retrospective data obtained from diagnostic cone-beam computed tomography of 90 skeletal Class III patients (mean age, 21.67 ± 2.93 years; range, 15.0-30.6 years) were divided into symmetry (n = 30) and asymmetry groups (n = 60). The asymmetry group was subdivided into roll (n = 30) and non-roll types (n = 30). The differences in body inclination and dental measurements (distance and angle) according to two mandibular planes (Body-MHP and Border-MHP) were assessed in the groups and subgroups. RESULTS Mandibular body inclinations relative to the Body-MHP were not different in the roll-type asymmetric mandible between the sides, while those relative to the Border-MHP were different (P < .001). For the mandibular first molar positions relative to the Border-MHP, the differences in vertical distance between the sides were undermeasured and the inclination differences were overmeasured when compared relative to the Body-MHP. CONCLUSIONS The Body-MHP demonstrated better bilateral similarity in body inclination compared with the Border-MHP in patients with roll-type facial asymmetry. The novel body mandibular plane ensures an accurate diagnosis for tooth movement and jaw surgery, particularly in the roll-type asymmetric mandible.
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