成人骨性Ⅲ类水平型偏颌患者牙颌三维对称性分析

Three-dimensional analysis of craniofacial symmetries in skeletal Class Ⅲ adults with translation-dominant type facial asymmetries

目的基于CBCT数据分析成人骨性Ⅲ类水平型偏颌患者偏斜侧与非偏斜侧的牙颌对称性。方法选取成人骨性Ⅲ类水平型偏颌患者31例(男10例,女21例),年龄(20.58±3.31)岁,对患者进行计算机断层扫描,获取DICOM数据,导入Mimics 21.0软件三维重建,选择牙齿及上下颌骨标志点进行测量,采用SPSS 22.0软件进行统计学分析。结果偏斜侧上下6转矩及UP、UF、Mx、LC、LF、LW、Go、Ag点到CMSP的距离大于非偏斜侧(P<0.05);LF、LW、Go、Ag点到FHP、CP的距离均小于非偏斜侧(P<0.05);偏斜侧髁突单位长度、颏单位长度、髁突内外径长度、下颌体总长度及升支高度均小于对侧(P<0.05)。结论该类偏颌患者上颌存在牙齿及基骨的水平向代偿;偏斜侧下颌骨位置相对于颅上颌复合体更向上、向外、向后;髁突单位及颏单位可能在下颌体的不对称生长中起作用。

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. 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.