The Effect of Basic Mandibular Movement on the Head and Trunk

本研究的目的是探讨基本的下颌运动对头部和躯干的影响，并确定开口范围与头部或躯干运动范围之间的关系。当受试者站立时，张开嘴巴时头部向后移动，闭上嘴巴时头部向前移动。嘴巴张开时身体向前移动，嘴巴闭上时身体向后移动。嘴巴张开的宽度与头、躯干的运动范围有显著的相关。在开合下颌运动时，观察到相关的头部和躯干运动。当嘴巴张开时，头部向后倾斜，导致头部重量在颈椎节上的平衡转移。为了补偿头部向后的运动，身体倾向于向前移动，反之亦然。此外，嘴张得越大，头部和躯干的运动范围也越大。这些发现表明，头部和躯干的运动促进了下颌的平稳运动。

The purpose of this study was to investigate the effect of basic mandibular movement on the head and trunk and determine the relationship between the range of mouth opening and the range of head or trunk movement. The head moved backward during mouth-opening and moved forward during mouth-closing, when the subjects were standing. The body moved forward as mouth opened and backward while the mouth closed. The width of mouth opening was significantly correlated with the range of head and trunk movement. During open-close mandibular movements, associated head and trunk movements were observed. When the mouth opened, the head tilted backward, resulting in a shift of balance with the weight of the head over the cervical segments. To compensate for the backward head motion, the body tends to move forward, and vice versa. Also, a wider opening of the mouth was correlated to a larger range of head and trunk movements. These findings suggest that head and trunk movements facilitated smooth movement of the jaws.