Changes in gait stability induced by alteration of mandibular position.

The purpose of this study was to investigate the effect of different mandibular positions on the body equilibrium by measuring the gait rhythm. Twelve young healthy subjects volunteered to participate in this study. Subjects were instructed to walk for a 18m distance with the mandible guided at six different positions by occlusal splints. The gait was recorded at fast, ordinary and slow walking speeds under occluded condition. Gait cycle, coefficient of variation for gait cycle and gait velocity were calculated during the 10m-walk. One-way ANOVA with repeated measures demonstrated significant differences among the six mandibular positions for the gait cycle at all gait speeds, for the coefficient of variation at fast speed and ordinary speed and for the gait velocity at fast speed (P<0.05). Regarding these variables, multiple comparison tests were also performed between the mandibular position without instruction for occlusion and other five mandibular positions. Gait cycle, coefficient of variation and gait velocity changed significantly in 5mm opening position from the intercuspal position, and in 5 mm left and 5mm right position from the 3mm opening position at fast speed (P<0.05). The result of this study suggests that the change of mandibular position could affect the gait stability.