下颌骨截骨术后咬肌变化的研究

【作者】 朱明； 柴岗； 张艳； 马晓飞； 俞哲元； 穆雄铮； 祁佐良；

【机构】 上海第九人民医院；

【摘要】 目的:观察下颌角截骨术后咬肌形态的长期动态变化。材料和方法:采集120例下颌骨斜形截骨受术者术前及术后3、6、12个月时头颅CT数据,并进行三维重建,通过软件平台设定合适的阈值范围,分离出咬肌组织。经过连续断层影像标定创建咬肌的三维分割体,由软件输出咬肌体积等三维信息。再选定三处横截面(B截面:过咬合平面水平,下颌升支前后缘中点的平面;A截面:B截面上1cm;C截面:B截面下1cm),在各横截面上测量咬肌的面积和厚度,观察咬肌在不同水平上的面积、厚度随时间的变化趋势。结果:咬肌体积与横截面积的变化趋势基本相同,体积在术后3、6、12个月时分别缩小至术前的82.02%、77.00%和80.43%,术后各时期体积均明显小于术前(P<0.05)。A、B、C平面横截面积的变化分别为A平面在术后各随访时期减小至术前的85.81%、78.86%和81.56%,B平面萎缩至术前的80.94%、75.03%和77.04%,而C平面最接近原下颌角角区下降最多,分别为13.46%、11.48%和13.89%。各测量数值与术前比较均有显著差异。咬肌厚度的变化为A平面在术后3、6、12个月时分别减小16.54%、15.85%、4.69%,术后12个月时与术前比较无明显差异。而B、C平面在各随访时间的厚度与术前比较均有显著差异。结论:下颌角截骨术使咬肌发生了自行萎缩,同时原角区(C截面)的咬肌萎缩最为明显。因此在下颌骨截骨的术前预测中应考虑到咬肌的萎缩,以更好地指导手术。更多还原

【Abstract】 Objective:To evaluate the morphological dynamic changes of masseter muscle after the mandibular angle oblique osteotomy.Methods:Computerized tomography(CT) examinations were performed on 120 patients treated by mandibular angle oblique osteotomy before operation and at 3,6,i2months after operation,respectively.The thickness and cross-sectional area of pre- and postoperative masseter muscle were evaluated using 3D CT images observed from 3 selected slice level,which paralleled with Frankfurt horizontal plane.Three-dimensional reconstruction was made for calculation of masseter muscle volume through software.Results:After surgery,the reduction of the masseter muscle volume and cross-sectional area was seen.Three months postoperatively,a significant reduction in the volume and cross-sectional area of the masseter muscle were shown.The volume of masseter muscle was reduced to 80.43%at 12 months postoperatively.The cross-sectional area of A^B^C planes reduced to 81.56%^77.04%03.89%, respectively.A tendency to revert back to the normal dimension was seen between 6 months and 12 months postoperatively,but there still was distinctive difference among all the measuring values.However,the change of its thickness didn’t display the same tendency.They reduced gently and the minimum didn’t appear in the same period. Nevertheless,we found the thickness of masseter muscle on the C plane have the sharpest decline.Conclusion:The results of this study suggest that the masseter muscle underwent significant atrophy after mandibular angle oblique osteotomy,and these changes should be the guidance for the design and simulation before operation.更多还原