Analysis of masseter muscle in facial asymmetry before and after orthognathic surgery using 3-dimensional computed tomography.
10.4041/kjod.2009.39.1.18
- Author:
Seung ah SEO
1
;
Hyoung seon BAIK
;
Chung ju HWANG
;
Hyung Seog YU
Author Information
1. Department of Orthodontics, College of Dentistry, Yonsei University, Korea.
- Publication Type:Original Article
- Keywords:
Masseter muscle;
Facial asymmetry;
Mandibular setback osteotomy;
Normal occlusion;
Thre dimensional computed tomography (3D CT)
- MeSH:
Facial Asymmetry;
Humans;
Mandible;
Masseter Muscle;
Orthognathic Surgery;
Osteotomy
- From:Korean Journal of Orthodontics
2009;39(1):18-27
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: The purpose of this study was to understand the differences in masseter muscle (MM) between the shifted and non-shifted sides in facial asymmetry patients, and the changes shown by MM after mandibular surgery. METHODS: Pre- and post-operative CT scans were performed on 12 Class III patients with facial asymmetry who were treated by intraoral vertical ramus osteotomy and 10 subjects with normal occlusion. Using the V-works 4.0 program (Cybermed, Seoul, Korea), 3-dimensional images of the mandible, and MM were reconstructed, and evaluated. RESULTS: In the asymmetry group, the MM angle between the shifted and non-shifted sides was only significantly different (p < 0.05). Compared with normal occlusion, the asymmetry group showed a significantly smaller volume and maximum cross-sectional area in both sides of MM (p < 0.05). After mandibular surgery, the angle of MM (p < 0.01) and differences in angle between the shifted and non-shifted sides of MM (p < 0.05) were significantly decreased. The thickness in the maximum cross-sectional area was significantly increased (p < 0.01). After surgery, MM in facial asymmetry patients was similarly changed to those in the normal occlusion group except for widths. CONCLUSIONS: MM in facial asymmetry was definitely different from those in normal occlusion. However, this study suggests that MM changed symmetrically in conjunction with the mandible after proper mandibular surgery.
