The Effect of Unilateral Mastication on Craniofacial Structures

Objective:  The purpose of this study was to determine if the craniofacial skeletal structure is associated with a unilateral mastication habit. Method:  Forty-eight individuals with a unilateral mastication habit and the same number of bilateral mastication individuals were enrolled in this study. The lateral and frontal cephalograms were taken and traced. The gonial angle and lateral ramal inclination were defined on the lateral cephalograms, and the ramal height and frontal ramal inclination were measured using the frontal cephalograms. All measurements were defined as being either on the right or left sides and then compared between the sides using paired t-tests. Result:  In the unilateral mastication group, measurements of the ramus height and frontal ramal inclination on the mastication side were significantly larger than those on the non-mastication side. Conversely, subsequent comparisons between the right and left sides in the bilateral mastication group showed that there were no significant differences in mandibular size and shape between the sides. Conclusion:  These results suggest that the craniofacial skeletal structure can be associated with the unilateral mastication habit.