3D-CT evaluation of facial asymmetry in patients with maxillofacial deformities

Objective: The aims of this study were to characterize the symmetrical features of patients with facial deformities and to suggest a classification system for facial asymmetry based on 3-dimensional-computed tomography (3D-CT) evaluation. Study design: Preoperative CT images were investigated for 49 patients with maxillofacial deformities. Asymmetry indices were calculated for some landmarks in the maxilla, mandibular body and the mandibular ramus regions. Results: Asymmetry was observed most frequently in the mandibular body region. The subjects were divided into 3 groups. Subjects without any asymmetry in the 3 regions were classified as Group I (44.9%). Groups II or III were defined for subjects without or with maxillary region asymmetry, respectively, and they were subcategorized. In Group IIA (8.2%), asymmetry was shown solely in the mandibular body region, and in Group IIB (18.4%), additional asymmetry was shown in the mandibular ramus region. Group IIIA (6.1%) showed asymmetry only in the maxillary region, and Group IIIB (22.4%) showed asymmetry in all 3 regions. Conclusion: The 3D-CT classification for facial asymmetry has the potential to replace the conventional cephalometric classification.