Poster 51: Masticatory Efficiency in Class III Dentofacial Deformities Before and After Orthognathic Surgery

Abstract

Dentofacial deformities are considered to be severe problems of malocclusion that require combined treatment with surgery, orthodontics and orofacial myofunctional therapy. Studies have demonstrated that individuals with dentofacial deformities present functional difficulties, with mastication being one of the functions most severely involved. To analyze the masticatory efficiency of individuals with Class III dentofacial deformities before and 6 months after orthognathic surgery compared to a control group. The study was approved by the Research Ethics Committee (protocol n° 4420/2008) and all participants gave written informed consent to participate. The study was conducted on 19 individuals with a diagnosis of Class III dentofacil deformity (DG-III), 10 men and 9 women (mean age: 24 years) and on 30 control volunteers (CG), 12 men and 18 women (mean age: 24 years) with no alterations in face morphology or dental occlusion, without missing teeth, except for the third molars, and without signs or symptoms of temporomandibular joint dysfunction. Masticatory efficiency was analyzed by the colorimetric method with capsules (beads), with the value of fuchsin concentration (μg/ml) being obtained for each capsule chewed. Each individual chewed one capsule at a time, being timed for a period of 20 seconds, with a 3-minute interval between chewing episodes. Two capsules were chewed in a habitual manner, 1 on the right side and the other on the left side, for a total of 4 capsules. In the statistical analysis, the values of masticatory efficiency were compared in DG-III before and 6 months after orthognathic surgery using the paired Student t test. The masticatory efficiency of DG-III before and 6 months after surgery was compared to that of CG by analysis of variance (ANOVA). The level of significance was set at P < .05. There was a statistically significant difference (P < .0001) in the masticatory efficiency of DG-III between the period before and after orthognathic surgery both in habitual free mastication and in unilateral mastication. A significant difference (P < .0001) in masticatory efficiency was also observed between CG and DG-III both before and after surgery regarding all masticatory tasks. Masticatory efficiency improved in individuals with Class III deformity after orthognathic surgery, although 6 months after surgery their values of masticatory efficiency were not equal to those of individuals without dentofacial deformities.