偏侧咀嚼的咀嚼肌肌电图分析

Effect of Unilateral Chewing on Electromyographic Activity of Masticatory Muscles

目的:通过对偏侧咀嚼患者咀嚼肌肌电图的分析,评估:⑴偏侧咀嚼是否会影响咀嚼肌的肌功能状况,⑵这种影响与性别、偏侧咀嚼持续时间的关系。方法:用肌电图仪分别记录16例(男女各8人,平均32.4岁)持续不同时间的偏侧咀嚼组和10例正常对照组在牙列轻接触、中度咬合和最大咬合时的嚼肌和颞肌前束的肌电数据,计算嚼肌的活动不对称指数(ASMM)和颞肌前束的活动不对称指数(ASTA),然后进行统计学分析。结果:⑴偏侧咀嚼组与对照组ASMM和ASTA在中度咬合和最大咬合时,有显著性差异(P<0.05);(2)偏侧咀嚼持续时间为0.5～2年组与5年组ASMM和ASTA无显著性差异(P>0.05);(3)男性组与女性组ASMM和ASTA无显著性差异(P>0.05)。结论:偏侧咀嚼的确会损害咀嚼肌的肌功能状况,但这种损害在5年内没有明显变化且与性别无关。

Objective： We used EMG to study the effect of unilateral chewing on masticatory muscle functions pattern. Methods： 16 subjects （8 males and 8 females,mean age 32.4） with unilateral chewing, and 10 subjects with free-sided chewing were used as control. Subjects were instructed to do light tooth contact ,moderate bite and maximum bite in inter cuspal position （ICP）, while EMG data from the left and right masseter and anterior temporalis muscles were recorded. Asymmetry index of masseter muscles （ASMM） and Asymmetry index of temporalis muscles （ASTA） were calculated and compared. In experiment group, ASMM, ASTA in different gender and in subjects with different lasting times were also compared. Results： Under moderate and maximum bite,ASMM and ASTA in unilateral chewing group were significantly higher than those in free-sided chewing group.There was no statistical differens between gender（P〉0.05）and lasting time（P〉 0.05） among unilateral chewing subjects. Conclusion： It could be suggested that a continuous unilateral chewing may damage the mastication muscles. The degree of damage isn＇t associated with gender and lasting time （〈5 years） of unilateral chewing.