无牙颌下颌骨大小和形态变化的初步研究

Preliminary Study of Changes of the Edentulous Mandibular Size and Shape

本实验对５６例无牙颌患者（２８例牙嵴丰满者和２８例牙嵴萎缩者）的Ｘ线侧位片，应用中轴转换方法得到下颌骨中轴各线距和角度。并测量其线距和角度。结果表明：随着牙嵴吸收的增加，下颌体长度和下颌支长度增加；前牙槽突、颏突、颌骨前部高度，颌骨后部高度及喙突长度减少。下颌体和下颌支的连接更趋于平坦；喙突和髁突更趋于接近；前牙槽突向舌侧倾斜。说明牙槽骨的吸收使下颌体高度发生较大的变化。

Abstract In this article 56 edentulous patients were selected and divided into a group of plump of alveolar ridge and a group of reduction.The lateral cephalographes were made for every subject.Each cephalograph was projected and the line distants and angles in mandibular medial axes were obtained by using the technique of medial axis transformation.The results showed as follows:The more resorption of the residual ridge,1.the lengths of mandibular body and ascending ramus increased;while the height of body,the lengths of superior alveolar,mental and coronoid axis decreased;2.a more downright mandibular ramus relative to the body; 3.a closer approximation of the coronoid and condylar processes;and 4.superior alveolar incline towards lingual side.It is suggested that the more change of the height mandibular body occur for resorption of alveolar ridge,while a series of charges of mandibular size and shape are happened.