头颅侧位定位片硬组织结构分级单元模型

MODEL THAT CRANIO-FACIAL HARD TISSUE WAS DIVIDED INTO CLASSIFICATION ELEMENTS ON LATERAL CEPHALOMETRIC X-RAY FILM

目的 建立头颅侧位定位片 ,便于空间解析几何分析的硬组织结构单元模型。方法 利用颅、颌、牙标志点二维坐标 ,根据解剖结构、兼顾考虑正畸治疗、正颌手术作用机理、作用部位划分颅、颌、牙分级单元。结果 一、便于精确计算各不规则结构面积大小 ,判断结构形态的变化。二、减少结构单元内的可变因素 ,利于判别。三、便于用空间解析几何分析法 ,分析点、边、角、面、多面体在位置、长短、大小、形态方面的协调、匹配。结论 该模型用于判断颅、颌、牙在位置、大小、形态方面协调、匹配情况 ,指导正畸治疗、正颌治疗方案的设计。

Objective To establish a model of cranio-facial hard tissue in sagittal plane for analysis with analyticgeometry.Methods Using coordinates of the skull、jaws、tooth and occluson landmarks, they were divided into classification elements according with anatomic structure、action machanism and action place of orthodontic treatment and orthognathic operation.Results Classfication elements were convenient to calculate the size of area of anomalistic structure; to distinguish the change of shape; to analysis the maching between points、edge、angle、area and polyhedran in place、size and shape with analyticgeometry.Conclusion This model for distinguishing matching between skull、jaws、tooth and occluson in place、size and shape. It may be applied to design project of orthodontic and orthognathic treatment.