咬合检测材料对咀嚼肌表面肌电的影响

目的探讨不同咬合检测材料在牙尖交错位（ICP）紧咬状态下对咀嚼肌肌电水平的影响。方法筛选30名大学生志愿者，分别在空白对照、口内放入咬合纸、口内放入T-Scan咬合片、口内放人T-Scan咬合架及咬合片（加架咬合片）等四种状况下作ICP最大紧咬，使用Bio-pak肌电图仪分别记录每组双侧颞肌前份（TA）及咬肌（MM）的肌电水平，并对四组数据进行比较分析。结果（1）与对照组相比．咬合纸组、咬合片组、加架咬合片组的TA、MM肌电幅值均升高；除加架咬合片组右侧TA（P〉0．05）外，其他差异均有统计学意义（P〈0．05）。（2）咬合纸组、咬合片组、加架咬合片组两两间比较差异无统计学意义（P〉0．05）。（3）与对照组TA不对称指数相比，咬合纸组、加架咬合片组差异有统计学意义（P〈0．05），而咬合片组则无统计学意义（P〉0．05）；与对照组的MM不对称指数相比，加架咬合片组不对称指数差异有统计学意义（P〈0．05），咬合纸组、咬合片组则差异无统计学意义（P〉0．05）。（4）与咬合片组TA不对称指数相比，咬合纸组、加架咬合片组差异有统计学意义（P〈0．05）。结论（1）不同咬合检测材料对所检测咀嚼肌肌电均有影响；（2）与加架咬合片相比．单纯咬合片对所检MM的肌电影响更小，因此对咬合检测结果的干扰更小。

Effect of occlusal examining materials on the surface electromyography of masticatory muscles

Objective To determine the influence of different occlusal materials on the surface electromyography （sEMG） of masticatory muscles in intercuspal position and clenching status. Methods 30 volunteers （aged 22 averagely ） were selected from university students. The muscle activity of the anterior temporalis （TA） and masseter muscle （MM） were evaluated by sEMG when mandible clenches on the natural dentition （blank controlling group） and other 3 occlusal conditions with various occlusal materials in between the upper and lower jaw： articulating paper （AP）, T-Scan sensor with support （TSS） and T-Scan sensor （TS） without support. Maximum activity and asymmetry index were compared and analyzed statistically. Results （1）Compared with the control group, significantly higher TA and MM activity were detected within the AP, TS and TSS groups （P 〈 0.05）, except for the right TA of the TSS group （P 〉 0.05）. （2）Muscle activity between groups AP, TS and TSS showed no significant difference （P〉 0.05）. （3）Compared with control group, asymmetry index of TA of AP and TSS group showed significant differences （P 〈 0.05）, but not in TS group （P 〉 0.05）; asymmetry index of MM of TSS group showed significant difference （P 〈 0.05）, but not in TS and AP group （P 〉 0.05）. （4）Compared with group TS, asymmetry index of TA showed significant differences between AP and TSS group （P 〈 0.05）. Conclusions （1）Insertion of T-Scan and articulating paper will change TA and MM muscle activity and asymmetry index in ICP maximum clench. （2）Compared with insertion of T-Scan sensor with support, insertion of T-Scan sensor without support has less effect on EMG of TA and MM in ICP maximum clench, .and therefore showed less interfere on the results of occlusal examiniation.