中文摘要：

目的：探讨下颌支矢状劈开截骨后退术后下唇感觉功能障碍的发生及其恢复的影响因素。方法：设置性别、远心骨段移动距离、下牙槽神经暴露情况3组变量，对随访时间达术后24周的19例37侧下颌支矢状劈开截骨术患者术后下唇感觉功能障碍情况进行研究。使用触觉检查、痛觉检查和两点辨别觉检查3种检查方法，参照BMRC感觉功能评定标准，观察在不同变量值的情况下，术后4周、12周、24周下唇感觉功能的变化。使用SAS6．12统计软件包，进行多个样本率的χ^2检验，了解下唇感觉功能障碍的发生及恢复情况。结果：性别差异对术后下唇感觉功能障碍程度无显著影响（P〉0．05）。下牙槽神经暴露者的术后下唇感觉优秀恢复率为25．0％，非暴露者为96．6％，两者差异有统计学意义（P〈0．05）。下颌骨远心骨段后退幅度〈6mm者，下唇感觉优等恢复率为100．0％，下颌骨远心骨段后退幅度I〉6mm者为68．2％，两者差异有统计学意义（P〈0．05）。结论：术中完全暴露下牙槽神经以及大幅度的下颌远心骨段后退会显著增加术后下唇感觉障碍的程度。在手术方案的设计中，将下颌后退幅度控制在6mm以内是比较安全的。

英文摘要：

PURPOSE： This study was designed to evaluate the influencing factors of sensory disturbance of lower lip after sagittal split ramus osteotomy（SSRO）. METHODS： We studied 19 consecutive patients that underwent a total of 37 SSROs from September 2004 to September 2005. The follow-up period was 24 weeks. The condition of sensory disturbance was measured using touch test, prick test and two-point discrimination test. The standard of the BMRC grading system was used to evaluate sensory function. SAS6.12 software package was used for Chi-square test. RESULTS： No significant differences of sensory disturbance was found between male and female（P〉0.05）. The recovery rates of sensory disturbance of lower lip had significant differences between patients who had intraoperative nerve exposure and patients who didn＇t have （P〈0.05）. If distal segment＇s movement was more than 6mm, the recovery rates of sensory disturbance of lower lip decreased from 100% to 68.2%, the difference was statistically significant （P〈0.05）. CONCLUSION： Intraoperative nerve exposure and greater amount of distal segment＇s setback will certainly increase the degree of sensory disturbance of the lower lip. It is suggested that the extent of movement is less than 6mm. Supported by National Natural Science Foundation of China （Grant No.30471897） and Shanghai Leading Academic Discipline Project （Grant No.Y0203）.