嚼肌B超图象与肌电幅值的对照研究

The study on masseter muscles with ultrasound images and EMG activity

作者对１０名正常男性青年嚼肌Ｂ超图像与肌电幅值进行了对照研究。作以下测试：①采用线阵超声诊断仪记录双侧嚼肌在牙尖交错位不咬（静止）和最大紧咬（收缩）时前后径冻结图像，测量视野内肌肉截面积及下颌骨升支前缘处嚼肌厚度；②采用肌电图仪记录双侧嚼肌在牙尖交错位作最大紧咬时的肌电图，测量峰值。结果表明Ｂ超图像所测嚼肌静止面积、收缩面积及收缩厚度均与嚼肌肌电值有明显线性正相关关系。作者认为用Ｂ超测量活体肌肉在功能状态时的截面积指标，对咀嚼肌肌肉作用力及其相互比例关系的确定，并以此为基础建立肌肉作用模型具有重要的意义。

In order to study the relationship between EMG activity and the ultrasound images of masseter muscle, 10 normal young males were examed with followings: 1. By means of ultrasound images of masseter mascle. The thickness and area of the cross section of masseter muscle were recorded when not-bitting (resting) and maximally bitting (contracting) at intercuspal position. 2. The peak of electromyographic activity of bilateral masseter mascles were recorded when maximally bitting at intercuspal position. The results showed that there were positive linear relationship between the ultrasound indexes that were contracting thickness,resting area, contracting area and electromyographic activity. It might concluded that muscle contract strength has a more close relationship with muscle cross-area and its thickness at contract condition.