下颌前突患者升支矢状劈开术前后咀嚼肌的肌电分析

目的测量下颌前突患者行正颌手术前后的肌电值，分析矢状劈开截骨术（SSRO）后咀嚼肌系统的变化，进一步探讨肌电的改变与术后咀嚼肌适应性改建之间的关系。方法选取18例接受SSRO治疗的下颌前突患者，记录术前及术后3个月、1年时主要咀嚼肌在功能运动中的电生理指标，计算相关参数并进行统计分析。结果下颌前突患者在正常状态下，大部分肌电指标低于健康对照组；行SSRO治疗后3个月，咀嚼肌的肌电指标有所下降，部分指标明显低于术前；术后1年，肌电指标较术前有明显上升，但部分仍低于健康对照组。结论正颌术后，咀嚼肌系统的重建是一个长期的过程，与术前相比较，咀嚼肌的性能得到了一定程度的改善。

Electromyography analysis on masticatory muscles of patients with mandibular prognathism before and after sagittal split ramus osteotomy

Objective To record the electromyography （EMG） of mandibular prognathism patients before and after orthognathic surgery, analyse the change process of masticatory muscles system after sagittal split ramus osteotomy （SSRO） and further explore the relationship between the electromyography changes and the adaptive remodeling of masticatory muscles. Methods We selected 18 simply mandibular prognathism patients who will accept SSRO. Recorded the electrophysiological parameters of masticatory muscles before the operation, after 3 months, after 1 year, and then calculated and analysed the parameters. Results The mandibular prognathism patients had lower EMG indexes under normal conditions. 3 months after SSRO, most of EMG indexes came down which were significantly lower than preoperative group. 1 year after SSRO, most of the EMG indexes improved a lot, while some of them were still lower than control group. Conclusion Reconstruction of masticatory muscle system after SSRO is a long-term process. The performance of masticatory muscles was improved by SSRO.