KennedyⅠ类牙列缺损修复前后咀嚼肌肌电变化分析

Masticatory muscle electromyographic changes before and after Kennedy Ⅰ dentition defect repair

目的探讨KennedyⅠ类牙列缺损患者修复前、后不同时期咀嚼肌肌电变化规律。方法双侧游离端牙列缺损患者34例,分别于修复前、初戴义齿及修复后1、3、6个月,在下颌姿势位和牙尖交错位最大紧咬时分别进行双侧咬肌、颞肌前束、胸锁乳突肌、二腹肌前腹的肌电检测,记录并计算其肌电幅值和不对称指数。结果下颌姿势位时,义齿初戴和修复后1个月时患者双侧咬肌、颞肌前束肌电幅值大于修复前(P<0.05),修复后3、6个月时双侧咬肌、颞肌前束肌电幅值与修复前比较差异无统计学意义(P>0.05),义齿初戴及修复后1、3、6个月时双侧二腹肌前腹肌电幅值大于修复前(P<0.05),双侧胸锁乳突肌肌电幅值与修复前比较差异无统计学意义(P>0.05),义齿初戴及修复后1、3、6个月时患者咬肌、颞肌前束不对称指数明显小于修复前(P<0.05),二腹肌前腹和胸锁乳突肌不对称指数与修复前比较差异无统计学意义(P>0.05);牙尖交错位最大紧咬时,义齿初戴及修复后1、3、6个月时双侧咬肌、颞肌前束、二腹肌前腹、胸锁乳突肌肌电幅值均高于修复前(P<0.05),义齿初戴及修复后3、6个月时咬肌、颞肌前束不对称指数低于修复前(P<0.05),修复后1个月时咬肌、颞肌前束不对称指数与修复前比较差异无统计学意义(P>0.05),义齿初戴及修复后1、3、6个月时胸锁乳突肌不对称指数小于修复前(P<0.05),二腹肌前腹不对称指数与修复前比较差异无统计学意义(P>0.05)。结论 KennedyⅠ类牙列缺损患者义齿修复后咀嚼肌功能得到明显改善,时间需≥3个月。

Objective To investigate the electromyographic changes of masticatory muscles before and after the repair of Kennedy I dentition defect. Methods Thirty-four patients with bilateral distal-extension partially edentulous were detected the EMG of masseter muscle （MM）, anterior temporalmuscle （TA）, sternoeleidomastoid muscle （SCM）, and anterior digastrics muscle （DA） at the mandibular postural position （MPP） and during the maximum clenching in intercuspal position （ICP） before repair, at the beginning of wearing new dentures, and 1, 3 and 6 months after repair. The EMG amplitudes and asymmetry indexes were recorded and calculated. Results The EMG amplitudes of MM and TA at MPP at the beginning of wearing new dentures and in 1 month after repair were significantly larger than those before repair （P〈0.05）, and showed no significant differences in 3 and 6 months after repair in comparison with those before repair （P〉0.05）. The EMG amplitudes of bilateral DA at the beginning of wearing new dentures, and in 1, 3 and 6 months after repair were significantly larger than those before repair （P〈0.05）, and there was no significant difference in the EMG amplitudes of SCM in comparison with that before repair （P〉0.05）. The asymmetry indexes of MM and TA at the beginning of wearing new dentures, and in 1, 3 and 6 months after repair were significantly smaller than those before repair （P〈0.05）, and the asymmetry indexes of SCM and DA showed no significant differences in comparison with those before repair （P〉0.05）. The EMG amplitudes of MM, TA, DA and SCM at ICP at the beginning of wearing dentures, and in 1, 3 and 6 months after repair were significantly larger than those before repair （P〈 0. 05）. The asymmetry indexes of MM and TA at the beginning of wearing dentures, and in 1, 3 and 6 months after repair were significantly smaller than those before the repair （P〈0.05）, and showed no significant differences in 1 month after repair in comparison with those before repair （P〉0.05）. The asymmetry indexes of SCM at the beginning of wearing dentures,and in 1, 3 and 6 months after repair were significantly smaller than those before repair （P〈0.05）, and the asymmetry indexes of DA showed no significant difference in comparison with that before repair （P〉 0.05）. Conclusion The masticatory function of the patients with Kennedy I dentition defect could be improved significantly after repair, and the repair lasts at least 3 months.