The effects of vertical dimension of occlusion on the direction of walking.

摘要

Aim. This study was designed to determine if unilateral changes in the vertical dimension of occlusion affected the direction of walking. We hypothesized that subjects were more likely to deviate to the contralateral side of the vertical dimension increase.;Methods. Fifty blindfolded subjects were filmed from behind while walking down a corridor for a total of 9 trials in a double-blind study with three different bite positions. The proportion of subjects deviating to either side was compared using the chi-square test.;A secondary analysis was performed to evaluate the influence of the dental midlines on the direction of walking. All statistical analyses were performed using SAS, Version 9.2 (SAS Institute, Cary, NC);Results. There was no statistically significant difference in the direction of walking based on unilateral vertical changes as per the study protocol. However, there was a positive association in a subgroup of patients with a midline deviation.;The results showed that out of 50 subjects included in the study, there were 43 subjects with oral midline deviations, 19 had the deviation to the left side and 24 had the deviation to the right side. The 19 subjects completed 171 trials of which the subject walked left 53% of the time, walked right 39% of the time and walked down the center 9% of the time. The right side midline deviation group completed 216 trials and walked left 42% of the time, walked right 34% of the time and walked down the middle 24% of the time. These results were statistically significant (p=0.0005).;A chi square test analyzing the preponderance of subjects presenting a left oral midline shift that walked to the left more than the right found a statistically significant difference between the two percentages ( 0.001).;Conclusions. The primary finding of this study is that a unilateral change in vertical dimension of occlusion did not affect direction of walking. However, in a subgroup with midline deviations an association was found between midline deviations and changes in direction of walking. There may be a possibility that disrupting aspects of the dental occlusion such as the midline position could affect a subject's ability to walk straight. Future studies may explore this possibility.