种植义齿修复牙列缺失后嚼肌肌电活动变化及意义

目的：评价种植义齿修复牙列缺失后咀嚼功能的改善程度。方法：应用种植覆盖义齿及固定义齿修复牙列缺失，定量分析嚼肌肌电图，并对照天然牙列及常规全口义齿修复。结果：在ICP位最大紧咬时，种植覆盖义齿的AMP值明显大于常规义齿，对应嚼肌较高肌力水平，在承受50％MVC时，其MPF值与对照组无显著差异，但150s出现明显下降变化。结论：种植覆盖义齿修复较常规全口义齿明显提高咀嚼功能，种植固定义齿的修复优势未能体现是因为患者担心咬合力过大造成种植体及上部结构破坏。

The Significance and Variations of Electromyographic Activity of the Masseter after Rehabilitation with Implant Prostheses on Edentulous

Objective:To evaluate the improvement of masticatory function after rehabiltation with implant prostheses on edentulous.Methods:The study was performed in edentulous patients with implant supported prosthetic reconstructions, and analysised the variation of myoelectrical signal parameters of masseter,and compared with those of the patients with natural teeth in the both jaws and the patients with the normal complete dentures.Results:During maximal voluntary contraction (MVC) In intercuspal position (ICP),surface electromyography indicated an creased amplitude myoelectrical output level that paralleled a higher bite force for implant prostheses compared with complete denture.At 50% MVC,the mean power frequency (MPF) weren't got the signifcance differences compared with the others,the downward shift of the MPF parameter occurred after 150 seconds for the implant overdentures.But no significance differences of the AMP gained between the implant fixed prostheses and the others,the MPF parameter variated unremarkablely.Conclusions:Compared with complete denture,masticatory function of masseter of edentulous after rehabilitated implant over-denture increased significantly,the absence of the myoelectrical signal variables in the implant fixed prostheses probably reflected a fear of biting too hard and fracturing the implant and the prostheses.