Purpose：The purpose of this study was to clarify the relationships between occlusal force and angular rate of sway of head, lumbar region, and center of gravity in older adults.

　Methods：The study included 25 independently-living older adults aged 65 years or over. An acceleration and angular rate sensor was attached to the head and the lumbar region, and the subjects maintained a static standing posture on a stabilometer. The measurement conditions were a combination of vision（eyes open, eyes closed）and occlusion（mouth open, occlusion）conditions, and body sway was measured over 30 sec. An oral assessment was performed, and occlusal force were measured. The subjects were divided into the higher occlusal force group and the lower occlusal force group with the median value of occlusal force as the cut-off, and the angular rate of sway of the head, lumbar region, and center of gravity were compared between the groups.

　Results：With the eyes closed and open-mouth condition, in the higher occlusal force group, the x-axis was 15.0±1.9 deg/sec, y-axis was 13.3±2.7 deg/sec, and z-axis was 7.5±1.8 deg/sec；in the lower occlusal force group, the x-axis was 22.4±17.0 deg/sec（p＝0.010）, y-axis was 20.1±8.8 deg/sec（p＜0.001）, and z-axis was 12.3±9.6 deg/sec（p＝0.046）. The angular rate of head sway in all directions was thus significantly less in the higher occlusal force group than in the lower occlusal force group. No significant differences in center of gravity sway or lumbar sway were found between the higher and lower occlusal force groups.

　Conclusion：A significant association was found between occlusal force and adjustment of head sway, suggesting that equilibrium function is related to head stabilization.