Editor's Comment and Q&A: Three-dimensional computed tomography analysis of mandibular morphology in patients with facial asymmetry and mandibular prognathism

Abstract

Introduction The purpose of this study was to investigate the dimensional changes in each skeletal unit in the mandibles of patients with facial asymmetry and mandibular prognathism. Methods The patients consisted of 50 adults with mandibular prognathism, divided into the symmetry group (n = 20) and the asymmetry group (n = 30) according to the degree of menton deviation. Three-dimensional computed tomography scans were obtained with a spiral computed tomography scanner. Landmarks were designated on the reconstructed 3-dimensional surface models. The lines to represent condylar, coronoid, angular, body, and chin units were used. Ramal and body volumes were measured in the hemi-mandibles. Results In the asymmetry group, condylar and body unit lengths were significantly longer, and coronoid unit length was significantly shorter on the nondeviated side than on the deviated side ( P P >0.05). Ramal volume was significantly greater on the nondeviated side ( P P >0.05). Conclusions Both condylar and body units appeared to contribute to mandibular asymmetry, with a more central role of the condylar unit.