正常翼外肌与翼外肌痉挛的肌电变化

Comparison of the electromyographic changes between the normal lateral pterygoid muscle and the lateral pterygoid muscle spasm

目的:对正常翼外肌、翼外肌痉挛患者进行研究,探讨正常翼外肌、翼外肌痉挛的肌电特征。方法:以35例单侧翼外肌痉挛成人患者为实验组,35例正常人为对照组。采用ZEP-500型诱发电位仪(中科电器高技术公司)测试翼外肌上下头在最大牙尖交错位(intercuspalposition,ICP)紧咬及张口1.0,2.5cm的肌电变化情况。结果:对照组翼外肌上、下头在ICP及开口运动中均有肌电活动;张口1.0cm时,翼外肌上头肌电变化较ICP时低,张口2.5cm时较张口1.0cm时升高,有显著性差异(P<0.05)。实验组ICP,翼外肌上、下头的肌电电位经统计学检验t值分别为0.60,0.74,无显著性差异(P>0.05);张口2.5cm时,低于对照组,翼外肌上、下头的肌电电位经统计学检验t值分别0.49,0.24,无显著性差异(P>0.05);张口1.0cm时,实验组肌电电位明显高于对照组,翼外肌上、下头的肌电电位经统计学检验t值分别2.15,2.31,有显著性差异(P<0.05)。结论:支持翼外肌上下头是协同肌肉,均表现为开口时收缩的观点;翼外肌痉挛时,张口1.0cm的电位明显高于正常翼外肌电位,可为临床诊断提供参考指标。

AIM:To observe the myoelectric manifestations of the lateral pterygoid muscle (LP) and the LP spasm through electromyography(EMG). METHODS:Thirty-five adult cases of unilateral spasm and 35 normal adult cas es were selected as experimental and control group respectively.EMG was used to record the myoelectric potentials of the anterior-posterior heads of LP in the maximal intercuspal position(ICP) and the mouth-opened position of 1.0 and 2. 5 cm evoked by ZEP-500 evoked potential instrument. RESULTS:Myoelectric movement occurred in the anterior-posterior heads of th e PL in ICP and the mouth opened position.The myoelectric potential of the anter ior LP was higher in the ICP and in the mouth-opened position of 2.5 cm as com pared with that in the mouth-opened position of 1.0 cm(P< 0.05).There was no s ignificant difference for the experimental group between the myoelectric potenti als in the LCP of the anterior-posterior heads of the LP(t=0.60,0.74,P >0.05). In the mouth-opened position of 2.5 cm,the myoelectric potentials in the exper imental group were lower than those of the control group,but no difference was s ignificant between the two groups(t=0.49,0.24,P >0.05).The myoelectric potential s in the mouth-opened position of 1.0 cm were significantly higher in the expe rimental group than in the control group(t=2.15,2.31,P< 0.05). CONCLUSION:It has been found that the anterior-posterior heads of the LP ac ted synergistically in the mouth-opened position.The myoelectric potential in the mouth-opened position of 1.0 cm was higher in the LP spasm than that in th e normal LP,used as a referent marker for the clinical diagnosis.