Effects of Changes of Mandibular position and Mandibular movement on Distribution of Foot Bottom Pressure

采用足底压力测量仪对下颌运动过程中足底压力的分布进行了研究。选取6名口腔系统及平衡功能无主客观异常的健康人作为研究对象。受试者被认为主观意识到主要的习惯性咀嚼方面。选取下颌静止位置和左右咀嚼口香糖作为下颌运动的测试条件。此外，对习惯咀嚼侧和习惯咀嚼侧进行了咀嚼试验，发现左右咀嚼口香糖时的身体摆动比下颌休息位置时小。这与以前报告的结果是一致的。当身体摆动作为X、y分量的基础进行分析时，下颌骨休息位置和牙龈左右咀嚼位置在身体摆动的X分量（左右）上没有明显差异。y分量（前后位）差异有统计学意义，即咀嚼口香糖时的身体摆动比下颌骨静止位置时小。由于在习惯咀嚼侧测试中对身体摇摆的分析也看到了类似的趋势，因此很可能每个受试者都没有受到咀嚼侧的影响。在这些结果的基础上估计足底压力的分布时，左、右口香糖咀嚼试验中检测足底压力的点数比下颌骨休息位置试验中检测足底压力的点多。而前者的压力大小也更大。由此可见，嚼口香糖对足底压力的分布有很大的影响。本研究结果表明，受试者在咀嚼口香糖时保持足底平衡以适应下颌运动，同时头部位置也随之发生变化。此外，还测量了齿套加载过程中的足底压力。受试者使用由ADA指定的定制的4型护齿器。结果表明，下颌骨静止位置与牙套加载时间的体摇无显著差异。因此，牙套载荷对机体摇摆的影响较小

An investigation was made on the distribution of foot bottom pressure during the mandibular movements using a measuring apparatus for foot bottom pressure. Six healthy persons who had no subjective and objective abnormalities in the stomatognathic system and the equilibrium functions were used as the subjects. The subjects were regarded to be subjectively aware of the major habitual chewing side. The rest position of mandibule and the left-right gum chewing were chosen as the test conditions of mandibular movement. Furthermore, gum chewing test in both the habitual chewing side and the other side was performed and the body sway was found smaller during left-right gum chewing than in the rest position of mandibule. This was consistent with the results of previous reports. When body sway was analyzed as the fundions of X,Y-components, significant differences in the X-component (left-right) of the body sway were not found between the rest position of mandibule and the left-right gum chewi … More ng. The differences in Y-component (antero-posterior) were significant between them, i.e., the body sway was smaller in gum chewing than in the rest position of mandible. Since similar tendency was also seen by the analysis of body sway in the habitual chewing side test, it was likely that there was no influence due to the chewing side of each subject. When the distribution of foot bottom pressure was estimated on the basis of these results, the number of points at which foot bottom pressure was detected was larger in left-right gum chewing test than in the rest position of mandibule test. And the magnitnde of the pressure was also larger in the former. Thus, it was indicated that the distribution of foot bottom pressure was much changed by gum chewing. The present results suggest that the subjects kept balance on foot bottom adapting to the mandibular movements for gum chewing and also head position changes associated with the movement. In addition, the foot bottom pressure during loading of mouth guard was measured. A custom-made mouth guard type 4, specified by ADA was applied to the subjects. The results showed that there was no significant difference in body sway between the rest position of mandibule and the time of mouth guard loading. Therefore, mouth guard loading was concluded to have little effects on body sway Less