咬合力および咬筋の筋活動量と筋横断面積を指標とした咬筋機能の評価

本研究对咬合力、咬肌厚度、咬肌截面积与肌活动量（EMG）的相关性进行了研究。【方法】检查对象：男性正常齿形15例，女性正常齿形15例（年龄24±2.6Y）。在最大咬合位和生理休息位分别测量咬肌的咬合力、厚度、咬肌截面积和肌电图。【分析】咬合力、咬肌厚度、咬肌截面积与肌电图的相关性质。分别用多元回归分析对咬合力的变量解释进行了检验。【结果】咬合力与生理休息位咬肌厚度、横截面积的相关系数分别为0.62 （p值0.0002）和0.54 （p值0.0016）。最大握拳量的相关系数分别为0.54 （p值：0.0019）和0.52 （p值：0.0027）。2. 咬合力与肌电图的相关系数为0.11 （p值为0.59）。3. 根据最大咬合时咬合力的变量解释分析，咬肌的变量解释回归系数分别为-0.03和0.53。静息位的回归系数分别为-0.05和0.52。【结论】从咬合力、咬肌厚度、咬肌截面积与肌电图的相关性分析可以看出，静止状态下咬合力与紧咬状态的相关性更强。然而，在评估咬肌的功能时，考虑咬合力和厚度在静止位置的情况更简单。

In this study, examination was done on the correlation among bite force, thickness, cross-sectional area of masseter muscles and the quantity of muscle activities (EMG), which were recorded at the same time.【Method】 Examination objects : 15 normal dentate males and 15 normal dentate females (age : 24 ±2.6Y.). The measurement of bite force, thickness, cross-sectional area of masseter muscles and EMG were done during maximum clenching and physiological rest position. 【Analysis】 The intensity of related nature of the correlation of bite force, thickness, cross-sectional area of masseter muscles and EMG.The variable explanation of bite forces was examined by multiple regression analysis respectively.【Result】 1. The correlation coefficient of bite force and thickness, cross-sectional area of masseter muscles in physiological rest position were 0.62 (p value : 0.0002) and 0.54 (p value : 0.0016). And the correlation coefficients in maximum clenching were 0.54 (p value : 0.0019) and 0.52 (p value : 0.0027). 2. The correlation coefficient of bite force and EMG was 0.11 (p value : 0.59). 3. Variable explanation of masseter muscles according to the analysis of variable explanation of bite force in maximum clenching showed the regression coefficients were -0.03 and 0.53. And in rest position showed the regression coefficients were -0.05 and 0.52.【Conclusion】 From the examination of the correlation among bite force, thickness, Crosssectional area of masseter muscles and EMG showed that correlation between bite forces in rest position was stronger compared to the clenching condition. However, in evaluation of function of masseter muscles, it is simpler to consider the situation where the bite force and thickness in rest position.