Higashi K
Osaka Daigaku Shigaku Zasshi. 1989 Jun;34(1):26-63.
Chewing movement is one of the most important functional and physiological jaw movements, and it is coordinated by the three elements of the functional occlusion system (teeth, TMJs and masticatory muscles). However, the relationship between chewing movement and these elements has not been clarified. The purpose of this study was to investigate the relationship between chewing movement and the activity of the masticatory muscles which directly control jaw movements. 25 subjects with normal stomatognathic function, 5 patients with MPD syndrome (muscle dysfunction group) and 5 patients with unilateral TMJ internal derangement (TMJ dysfunction group) were selected. 6 gums with different hardness were used as the test bolus. Sirognathograph Electromyograph Analysing System was used to simultaneously record chewing movements and electromyograms of the right and left masseter, anterior temporal, posterior temporal and anterior belly of digastric muscles. Using the analysing software which was developed for this study, chewing movements and muscle activities were analysed. The results were as follow; A. In normal subjects 1. Gum hardness influenced durations of the closing and occluding phases, maximum opening and closing speed, opening degree and deviation of opening and closing path. 2. Gum hardness influenced muscle activities except of the time factors of digastric bursts. 3. Durations of the closing and occluding phases were found to be related with the elevator muscle activities. Maximum closing speed was related with the masseter and anterior temporal muscle activities. Deviation of closing path was related with the anterior and posterior temporal muscle activities. B. In abnormal subjects 1. The changes mainly observed in the muscle activities were found to be significantly different between the muscle dysfunction group and normal group. Similarly, the changes mainly observed in the chewing movements were different between the TMJ dysfunction group and normal group. 2. When compared with the relationships in normal subjects, changes were observed in the relationships for closing movement in the muscle dysfunction group. In contrast, changes were observed in the relationships for opening movement in the TMJ dysfunction group. From the results, close relationships were found between chewing movements and muscle activities, and were characteristically influenced by stomatognathic dysfunction.
咀嚼运动是颌骨最重要的功能和生理运动之一，它由功能咬合系统的三个要素（牙齿、颞下颌关节和咀嚼肌）协调。然而，咀嚼运动与这些要素之间的关系尚未阐明。本研究的目的是调查咀嚼运动与直接控制颌骨运动的咀嚼肌活动之间的关系。选取了25名口颌功能正常的受试者、5名患有MPD综合征的患者（肌肉功能障碍组）和5名单侧颞下颌关节内紊乱的患者（颞下颌关节功能障碍组）。使用6种不同硬度的口香糖作为测试团块。采用下颌运动轨迹-肌电图分析系统同时记录左右咬肌、颞前肌、颞后肌和二腹肌前腹的咀嚼运动和肌电图。使用为本研究开发的分析软件对咀嚼运动和肌肉活动进行分析。结果如下：A. 在正常受试者中1.口香糖硬度影响闭口和咬合阶段的持续时间、最大开闭速度、开口度以及开闭路径的偏差。2. 口香糖硬度影响肌肉活动，但不影响二腹肌爆发的时间因素。3. 发现闭口和咬合阶段的持续时间与升肌活动有关。最大闭口速度与咬肌和颞前肌活动有关。闭口路径偏差与颞前肌和颞后肌活动有关。B. 在异常受试者中1. 发现肌肉功能障碍组与正常组之间主要在肌肉活动中观察到的变化存在显著差异。同样，颞下颌关节功能障碍组与正常组之间主要在咀嚼运动中观察到的变化也不同。2. 与正常受试者的关系相比，肌肉功能障碍组在闭口运动的关系中观察到变化。相反，颞下颌关节功能障碍组在开口运动的关系中观察到变化。从结果来看，咀嚼运动与肌肉活动之间存在密切关系，并且受到口颌功能障碍的显著影响。
