Abstract
The purpose of this study was to investigate the influence of abnormal occlusion on the relationship between the mandibular rotation and the mandibular incisal position during chewing movements.
Measurement of mandibular movements during mastication was made using the Sirognathograph Analyzing System in 25 subjects with normal occlusion, 10 subjects with non-functional side occlusal interference and 10 subjects with posterior crossbite.
At closing phase, interferece subjects showed no correlation between the rotation around the anteroposterior axis and the lateral deviation. The rotation around the vertical axis and the lateral deviation exhibited correlation in the middle of closing (p<0.05), but the regression coefficient is less than normal subjects. Crossbite subjects showed correlation between the both rotation and the lateral deviation (p<0.05), but the regression coefficient is greater than normal subjects.
Consequently, relationship between mandibular rotation and mandibular incisal position varies with occlusion. It is suggested that measuring mandibular rotation is important to comprehend the injury of abnormal occlusion to stomatognathic system.
