上海地区正常成人X线头影的图形质心分析

Centrographic analysis in Shanghai adults with normal occlusion

目的:建立上海地区正常成人图形质心分析法(centrographic analysis,CGA)的正常范围。方法:选取上海地区汉族正常成年人75名(男34名,女41名),年龄18～21岁。拍摄X线头颅侧位定位片,进行图形质心分析。并与高加索人的面部形态进行比较。采用SAS9.2软件包对所得数据进行统计学分析。结果:获得上海地区正常成人图形质心分析法的正常范围,其中面部质心位于Ba-A线上;面上部质心位于质心平面上;面下部质心位于质心平面前方0.92～1.29mm;下切牙长轴经过下颌骨性联合部的后1/3;上切牙长轴经过眶点后方,并与下切牙形成良好的覆、覆盖关系;上下唇前缘位于外平面处。各测量指标在男女性别之间无显著差异(P>0.05)。结论:正常成人X线头影的图形质心分析存在地区和种族差异,与高加索人相比,上海人下颌位置相对靠前,上、下切牙唇倾,面下1/3软组织略突。

PURPOSE： To obtain the reference value of centrographic analysis of Shanghai adults with normal occlusion. METHODS： Seventy five subjects of Han nationality at permanent dentition with normal occlusion were selected from Shanghai region （34 males, 41 females, age rang：18-21 years）. Centrographic analysis was conducted on the basis of the lateral cephalograms, and the obtained data was compared with that of Caucasian. SAS9.2 software package was used for statistical analysis. RESULTS： The reference value of centrographic analysis in Shanghai adults with normal occlusion was established. The facial centroid was located on the Ba-A plane; the upper centroid was positioned on the centroid plane; the lower centroid was positioned anterior to the centroid plane within 0.92-1.29mm; the long axis of lower incisor was positioned posterior to 1/3 Ba-Gn plane sympbysis intersection; the long axis of upper incisor was positioned posterior to orbitale and the upper incisor was positioned in proper occlusion with the lower incisor. The lips were positioned on the outer profile plane. There was no significant difference between male and female adults （P〉0.05）. CONCLUSIONS： Compared with that of Caucasians, mandibular position of adults in Shanghai was in a relative forward position, the incisor was labially inclined and the soft tissue in the lower 1/3 of the face was convex slightly. Supported by Shanghai Leading Academic Discipline Project （S30206）.