中文摘要：

目的：观察翼外肌在颞下颌骨髁突矢状骨折愈合时新骨形成中的作用。方法：24只绵羊随机分为2组，每组各12只，实验组：髁突截骨术造成绵羊右侧髁突矢状骨折，保留翼外肌；对照组：髁突截骨术造成绵羊右侧髁突矢状骨折，离断翼外肌。分别于术后4、12、24周3个时间点实验组及对照组各处死4只动物，进行显微CT（Micro-CT）扫描，观察分析骨折区新生骨的骨小梁数量（trabeculanumber，Tb．N），骨小梁厚度（trabeculathickness，Tb．Th），骨体积分数（bonevolumefraction，BV／TV）及骨小梁间隙宽度（trabeculaspace，Tb．SP）的变化，并用方差分析法对数据进行统计学分析。结果：实验组髁突形态改变较对照组明显，显微CT图像新生骨小梁结构显示清晰，Tb．N、Tb．Th、Bv／TV增加（P〈0．05），Tb．Sp减小（P〈0．05），组间比较差异均具有统计学意义（P〈0．05），对照组各参数变化无统计学意义（P〉0．05）。结论：翼外肌在颞下颌关节矢状骨折愈合过程有促进新骨形成的作用。

英文摘要：

Objective： To investigate the role of the lateral pterygoid muscle in the new bone formation during healing of sagittal fracture of the mandibular condyle. Methods： Oblique sagittal fracture on the right condyle of 24 adult sheep was made by osteoto- my. In the control group（n = 12） the lateral pterygoid muscle was cut, and in the experimental（n = 12） was not. 4 sheep were killed at 4, 12 and 24 weeks after oPeration respectively. Three-dimensional reconstruction was performed by miero-CT, the tra- beeula number（Tb. N）, trabeeula thickness（rib. Th）, trabeeula spaee（Tb. Sp） and bone volume fraction（BV/TV） of the frac- tured condyles were measured, the data were analyzed by SPSS 13.0. Results： The shape of condyle was changed more in the ex- perimental group than in the control. In the experimental group Tb. N, Tb. Th and BV/TV increased（ P 〈 0.05 ）, Tb. Sp decreased （P 〈0.05 ）. The parametem in the 2 groups were statistically different（P 〈 0.05 ）. In the control group the parameters were not signifieantly changed （P 〉 0.05 ）. Conclusion： The lateral pterygoid muscle can promote the new bone formation in the reconstruc- tion of the mandibular condyle during healing of sagittal fracture.