Chewing path and chewing rhythm in adult female patients with open-bite malocclusion

Abstract

This study was designed to assess the opening distance, chewing width and chewing rhythm in 10 normal female subjects and 22 female open-bite subjects in order to demonstrate how morphological characteristics of open bites have an affect on the masticatory jaw movements.
The data during gum chewing was processed by an automatic masticatory movement analyzing software system and statistically compared between two groups. The following results were obtained.
1. Mean values of the normal group for opening distance and chewing width were 14.5, 2.4mm and those of the open bite group were 12.8, 1.6mm, respectively. Between the two groups, there were statistical differences in terms of opening distance.
2. Mean values of the normal group for the opening, closing, occluding and cycles times were 207, 198, 184, 589 msec, and those of the open bite group were increased to 283, 235, 224, 741 msec, respectively. Between the normal and the open bite groups, there was a significant statistical difference in the closing time and the occluding time, and there was a highly significant statistical difference in the opening time and the cycle time.
The results therefore suggest that the chewing paths of the female open-bite patients have a tendency to get each chewing path and the chewing rhythm are slowed.