The Influence of Craniofacial Form on Bite Force and EMG Activity of the Masticatory Muscles

I. Analysis of Craniofacial Forms

Abstract

While jaw functions as cooperative work of the jaw muscles and the nervous system appear in craniofacial regions, the forms of their appearance are said to vary according to the differences in craniofacial forms in which the jaw functions appear. Hitherto, a number of reports have been published on relationships between jaw functions including bite force and facial forms, but none of them clearly reports on morphological classification methods in examining the relationship between jaw functions and facial forms. So, in this study, the authors analyzed the craniofacial regions as fields in which the jaw functions appear and conducted their grouping according to morphological and functional differences, using cephalometric photographs. As the first step, the authors attempted to establish, and examined, indices for different groups, the indices that most clearly indicate on the cephalometric photographs the morphological differences in the craniofacial regions. As a result, it was found that SN-MP on the cephalometric photographs are the most effective as indices showing the morphological characteristics of the craniofacial regions.