颌骨偏斜的三维分析及分类研究

Three Dimensional Analysis and Classification of Maxillomandibular Asymmetry

目的:以面部及下颌骨正中矢状面为参考平面,从颌骨位置和下颌骨轮廓2个方面对面部偏斜进行分析和分类,为临床诊疗提供依据。方法:利用ProplanCMF根据86例面部偏斜患者的术前CBCT资料构建骨组织的三维模型及三维测量体系,从颌骨位置和下颌骨轮廓2个方面分析偏斜特点并建立一种分类体系。结果:颌骨偏斜分为3类:位置偏斜、下颌骨形状偏斜、位置和下颌骨形状均偏斜。位置偏斜有T类(水平向偏斜)和V类(垂直向偏斜)。T1和T3类中,偏侧的下颌骨体长度、下颌升支高度、正面升支倾斜度、侧面升支倾斜度和对侧相比有统计学差异(P<0.01);下颌平移偏斜病例数太少,不纳入统计分析;V类中,偏侧的正面升支倾斜度、下颌升支高度与对侧相比有统计学意义(P<0.01),而下颌骨体长度、侧面升支倾斜度无统计学意义(P>0.05)。偏侧与对侧的轮廓测量项目相比有统计学意义(P<0.05)。结论:颌骨偏斜分类系统能够详细的反映颌骨位置和下颌骨形状的偏斜特点,对疾病的诊疗提供一定的临床依据。

Objective.. To three--dimensional analyze and classify the maxillomandibular asymmetry from jaw posi- tion and mandibular shape and to provide basis for clinical diagnosis and treatment using midsagittal plane of facial and mandible as the reference plane. Methods： The preoperative CBCT data of 86 patients with facial asymmetry were imported in Proplan CMF software to construct 3D model of bone tissue and 3D point measurement system. The characteristics of asymmetric deformity were analyzed from jaw position and mandibular shape and a new classi fication system was established. Resuits： Maxillomandibular asymmetry was divided into three categories： jaw posi- tion deviation, mandibular shape asymmetry, and both jaw position and mandibular shape deviation. Jaw position deviation included type T （transverse asymmetry） and type V （vertical asymmetry）. In T1 and T3 groups, body length, ramus length, lateral ramal inclination, and frontal ramal inclination were significantly different between the deviated side and the contralateral side （P〈0.01）. The number of mandibular translational deviation cases was too small to be included in statistical analysis. In type V, frontal ramal inclination and ramus length were significantly different between the deviated side and the contralateral side （P〈0.01）. However, the others were not statistically significant. The differences of contour measurement items of two sides were statistical significance （P〈0.05）. Conclusion： The classification system of maxillomandibular asymmetry can provide clinical basis for diagnosis and treatment.