Food textural study by mastication pressure, palatal pressure and electromyography

在进食过程中同步测量咀嚼肌电图（EMG）和第一磨牙的压力以及上颚三个点的压力。用表面电极测量左、上咬肌和颞肌肌电图。咀嚼压力通过嵌入人工第一磨牙的压力传感器来检测，这颗人工第一磨牙是用来代替失去的天然牙齿的。在舌侧的腭保持器表面嵌入压力传感器来检测腭压力。不同质地的食物，如含有1%至7%的明胶、加工过的奶酪、萝卜、杏仁和芋头等，被用作测试样本。咀嚼压力和肌电图最具特征的模式取决于食物的质地，与第一口食物的第一次变形相对应。咀嚼压力积分与首咬肌电信号振幅积分具有较好的相关性；也就是说，咀嚼压力所做的功与咀嚼肌的活动有关。然后信号模式变得相似，不依赖于食物的质地。随着咀嚼的进行。最大肌电电压也与第一口咀嚼时的最大咀嚼压力有关，可以借助肌电图推断出食物最大咀嚼压力的近似值。凝胶肌电图显示舌压和腭压可咀嚼的无节奏、相对连续的模式。随着凝胶黏稠度变硬，肌电图增加并显示出节律性模式，而腭压没有增加。肌电图从连续型到节奏型的变化表明，随着凝胶密度的增加，用舌头和上颚咀嚼的凝胶密度转变为用牙齿咀嚼的凝胶密度。

Mastication electromyograms (EMG) and the pressure on a first molar tooth, as well as the pressure on three points of the palate were synchronously measured during eating. EMG of the left and hight masseter and temporalis muscles were measured with surface electrodes. The mastication pressure was detected by a pressure transducer embedded in an artificial first molar tooth that had been fitted to replace a lost natural tooth. The palatal pressure was also detected by pressure transducers embedded in the palatal retainer surface on the tongue side.Foods with various texture' e. g., 1 to 7% of gelatin gels, processed cheese, radish, almond and takuan were used as test samples.The most characteristic patterns depending on food texture for both the mastication pressure and EMG were obtained with the first bite, corresponding to the first deformation of the food eaten. The integral of the mastication pressure correlated well with that cf the EMG amplitude for the first bite ; i. e., the work done by mastication pressure was related to the activity of the masticatory muscles. The signal patterns then became similar, not depending on the food texture. as mastication proceeded. The maximum EMG voltage was also related to the maximum mastication pressure with the first bite, it being possible to deduce an approximate value for the maximum mastication pressure on the food with the aid of EMG.EMG for gel, which could be masticated by the tongue and palatal pressure, showed a non-rhythmic, relatively continuous pattem. As the gel consistency become harder, EMG increased and showed a rhythmic pattem in contrast to no increment in the palatal pressure. The change in EMG from a continuous to rhythmic pattem shows the density of the gels at which mastiction with the tongue and palate changes to that with the teeth, as the density of the gel increased.