偏侧咀嚼干预治疗改善咬肌活动不对称性的肌电分析

Changes of masseter muscle asymmetry due to unilateral mastication after intervention: a electromyographic analysis

目的运用咬肌肌电图分析偏侧咀嚼干预的效果。方法 43例患者(男19人,女24人,平均年龄20.0±0.5岁)根据有无诱因和是否干预分为4组:去诱因不干预组(A0)、去诱因干预组(A1)、无诱因不干预组(B0)和无诱因干预组(B1)。用肌电图仪分别记录各组前后在下颌姿势位(MPP)、牙尖交错位(ICP)最大紧咬运动和咀嚼运动时的咬肌肌电图,计算咬肌的活动不对称指数(ASMM),分析比较各组前后咬肌肌电活动的变化。结果(1)A0组在MPP、ICP最大紧咬运动和咀嚼运动中ASMM去诱因前后差异均无统计学意义;(2)A1组干预后在MPP、ICP最大紧咬运动和咀嚼运动中ASMM显著低于干预前;(3)B0组在咀嚼运动中实验前后差异有统计学意义;(4)B1组干预后在MPP、ICP最大紧咬运动和咀嚼运动中ASMM较干预前显著降低。结论偏侧咀嚼无论有无诱因均应干预治疗,有诱因则在诱因去除后进行。

Objective To explore the effect of intervention with unilateral mastication on masseter muscle asymmetry. Methods Forty-three subjects （19 males and 24 females, mean age 20.0 ± 0.5 years） with unilateral chewing were divided into group A0 with motivation and without intervention, group A1 with motivation and intervention, group B0 without motivation or intervention, and group B1 without motivation but with intervention. In groups A0 and A1, the motivation was removed and groups A1 and group B1 received interventions. Surface electromyography was recorded using surface electromyography in all the subjects in mandible postural position （MPP）, with maximum clenching in intercuspal position （ICP） and during chewing. The sEMG of the left and right masseter muscle were separately recorded to assess the asymmetry index of the masseter muscles （ASMM） and its changes after intervention. Results In groupA0, the ASMM at MPP, during maximum clenching and chewing had no obvious changes after removal of the motivation. In group A1, the ASMM at MPP, during maximum clenching and chewing were obviously decreased after intervention. In group B0, the ASMM at MPP and during maximum clenching showed no obvious changes but ASMM during chewing significantly increased after removal of the motivation. In group B1, the ASMM at MPP, during maximum clenching and chewing all decreased obviously after intervention. Conclusion Interventions can significantly improve the bilateral symmetry of the masseter muscles in subjects with unilateral chewing, and the motivation for unilateral chewing should be removed before intervention.