SSRO术前后髁状突骨密度测定

Determination of condylar bone density in patients with mandibular protrusion before and after sagital split ramus osteotomy.

目的 :探索双侧下颌升支矢状劈开 (SSRO)术后髁状突骨组织改变情况 ,以了解正颌手术对颞下颌关节的影响。方法 :采用计算机数字图象系统 ,在手术前后不同时期X片上 ,将髁状突分成四个大致相等的测量区域 ,分别测量统计各区的骨密度值。结果 :在不同因素下 ,髁状突骨密度有所不同。术前 :2、4区高于 1、3区 ,右侧高于左侧。术后 :骨密度下降 ,可以不同方式表现。结论 :髁状突位置发生改变后 ,其骨组织将起代偿作用。计算机数字图象系统可使髁状突骨密度测定更为准确 。

Objective:The purpose of this study was to explore the alteration of the bone tissue of condyle after SSRO . Methods:The bone density of mandibular condyle determined by 4-rectangle-room method was processed by a computer digital image analyzing system in 12 patients with X-ray in preoperation and postoperation .Results:The density varied with different factors and had some characters in the patients :①zone 2 and 4 were thicker than 1 and 3 before surgery ,and the rights were denser than the lefts in the left lateral deviation of mandible . ② the density was thinner after surgery ,which changed from rareness to denseness . Conclusions:The result indicated: the bone tissue of condyle could make compensation for the position of condyle altered . It was demonstrated that the application of computer digital image processing technologies in determination of condylar bone density was more precise , and that the lesion of condylar bone was found earlier.