目的联合应用肌电图仪与咬合分析仪评价骨性Ⅲ类患者正颌术后的肌肉及咬合情况的变化。方法收集15例骨性Ⅲ类正颌手术患者及15例正常患者,病例组在正颌术后3个月、6个月、1年分别进行BiopakⅡ肌电图仪与T-ScanⅢ咬合分析系统同步测量,使用配对t检验比较各组间的差别。结果除息止位外,术后6个月组肌电电位及总力显著高于3个月组(P<0.05);术后1年组功能运动时主要活动肌肉的肌电电位显著高于术后6个月组(P<0.05),正常组主要活动肌肉的肌电电位和总力显著高于术后1年组(P<0.05),其余指标无显著性差别。结论骨性Ⅲ类患者正颌手术后1年中,肌肉及咬合功能逐渐增强,但变化不完全同步,且都不能达到正常水平。 Objective To evaluate the changes of muscle and occlusal status of orthognathic surgery in patients with skeletal Class Ⅲ by electromyography and occlusion analyzer. Methods Fifteen patients with skeletal Class Ⅲ orthognathic surgery and 15 normal controls were enrolled in this study. The patients were treated with BiopakⅡ electromyography and T-Scan Ⅲ occlusion analysis system at orthognathic surgery for 3 months, 6 months and 1 year respectively. Simultaneous measurement, using paired t-test to compare the differences between groups. Results Except for rest position, the EMG potential and total muscle force at 6 months postoperatively were significantly higher than those at 3 months (P <0.05). The electromyographic potential of major active muscles at 1 year postoperative functional exercise was significantly higher than that at 3 months The muscle EMG and total muscle force of the main active muscles in the normal control group were significantly higher than those in the 1-year postoperative group (P <0.05). There was no significant difference between the other groups. Conclusion In the one year after orthognathic surgery, the function of muscle and occlusal gradually increased in skeletal Class Ⅲ patients, but the changes were not completely synchronized and could not reach the normal level.