关键词: 颜面不对称, 水平型偏颌, 骨性Ⅲ类, 锥体束CT, 对称性

Abstract: Objective　 To analyze the craniofacial characteristics in the deviated side and the non-deviated side of skeletal Class Ⅲ adults with translation-dominant type (T-type) facial asymmetries using cone-beam computerized tomography (CBCT). Methods　 Thirty-one skeletal Class Ⅲ adult patients with T-type facial asymmetries, 10 males, 21 females, 20.58±3.31 years old, were included. CBCT scanner was used to obtain DICOM data from the patients before treatment. Three-dimensional reconstruction was performed with Mimics 21.0 software. Teeth, maxilla and mandible were selected for measurement. And the results were statistically analyzed with SPSS 22.0. Results　 The torque of first molar and the distances from UP, UF, Mx, LC, LF, LW, Go and Ag to the craniomaxillary median sagittal plane (CMSP) on the deviated side were greater than those of the non-deviated side (P < 0.05), while the distances from LF, LW, Go and Ag to the FHP and CP were all smaller on the deviated side (P < 0.05). The lengths of condyle unite, mental unit, condyle, mandibular body and the height of mandibular ramus on the deviated side were all smaller than those on the opposite side (P < 0.05). Conclusion　 There are horizontal compensations of teeth and basal bones in the upper jaw of these patients. The position of the mandible is more upward, outward and backward on the deviated side when the reference planes are based on cranial-maxillary complex. Condylar unit and mental unit may play a role in the asymmetric growth of mandibular body.

Key words: facial asymmetry, translationdominant type, skeletal Class Ⅲ, CBCT, symmetry