咬合重建对咀嚼肌肌电图协同模式的近、远期影响

目的:探讨咬合重建修复对牙齿重度磨耗患者咀嚼肌肌电图之间协同模式的近、远期影响.方法:选择29例重度磨耗患者进行咬合重建修复,分别测量修复前、过渡修复1个月、永久修复1个月以及远期复查(平均3.5年)时在息止位、大力咬合及咀嚼运功时嚼肌、颞肌前束和颞肌后束的表面肌电图,对比分析左、右侧同名肌的不对称指数,嚼肌/颞肌前束,嚼肌/颞肌后束和颞肌前束/颞肌后束的活动指数在修复前、后的变化.结果:(1)在息止位、大力咬合及咀嚼时各咀嚼肌的不对称指数在咬合重建的各期较修复前均有下降趋势;(2)咬合重建后各期,嚼肌/颞肌前束的活动指数无明显变化;(3)咬合重建修复后,嚼肌/颞肌后束及颞肌前束/颞肌后束活动指数在大力咬合与咀嚼运动时均明显增加.结论:咬合重建修复能明显改善重度磨耗患者同名咀嚼肌的对称性,并能改变不同咀嚼肌之间的相对活动强度.

Short-term and long-term effects of occlusal rehabilitation on the co-contractration patterns of the electromyography of masticatory muscles

OBJECTIVE: To investigate the short-term and long-term effects of occlusal rehabilitation on the co-contractration patterns of masticatory muscles of patients with extensive tooth wear. METHODS: Twenty-nine patients with severe tooth wear were selected and conducted with occlusal rehabilitation. The surface electromyography (EMG) of masseter (MM), anterior temporalis (TA) and posterior temporalis (TP) at rest position, during clenching and chewing were separately recorded in the stage of pre-treatment, 1 month after temporary restoration, 1 month after permanent restoration and long-term observation (mean 3.5 years). The Asymmetry Indexes (AI) of bilateral muscles, Activity Indexes of MM/TA, MM/TP and TA/TP were compared in each stage. RESULTS: (1) After occlusal rehabilitation, all the AIs of bilateral MM, TA and TP at rest position, during clenching and chewing showed obvious decrements. (2) In every stage of occlusal rehabilitation, all of the Activity Indexes of MM/TA at rest position, during clenching and chewing had no obvious changes. (3) The Activity Indexes of MM/TP and TA/TP during clenching and chewing significantly increased after occlusal rehabilitation. CONCLUSION: The treatment of occlusal rehabilitation can significantly improve the bilateral symmetry of masticatory muscles in patients with extensive tooth wear, and also change the coordinated EMG activity of different masticatory muscles.