Masticatory pattern of mouth breathers before and after the disjunction of the upper jaw

Abstract

Purpose: To assess the chewing type in mouth Breathers pre- and post-maxillary expansion. Methods: Chewing patterns of 31 patients, ages from 7 up to 14 years, were evaluated with the aid of video recording. The mastication type, jaw movements and chewing speed were compared before and after maxillary expansion. Additionally, the findings before the maxillary expansion and the data found after maxillary expansion between the different masticatory types were contrasted among themselves, separately. The nonparametric tests of Wilcoxon and Mann Whitney were used, respectively. Results: Before maxillary disjunction, 41.9% of the patients presented alternate bilateral chewing and 58.1% displayed unilateral preferential (66.7% at right side). After maxillary expansion, 64.15% showed alternate bilateral chewing, 19.4% unilateral preferential and 16.45% unilateral chronic type. Significant changes in the cycles, in the chewing speed, or in the quantity of mandibular movements were not noticed while comparing the findings obtained before with those obtained after maxillary expansion

however, there was a significant decrease in jaw movements without rotating component when compared the alternate bilateral and the unilateral preferential types. Individuals with alternating bilateral chewing showed a distinguish increase in mandibular movements during the execution of the masticatory function after the completion of rapid maxillary expansion. Conclusions: Although maxillary expansion was not enough to cause significant changes in masticatory function of mouth breathers, the results indicate a more favorable condition in the execution of masticatory function in orthodontic treated mouth breathers who presented alternate bilateral mastication previously the upper jaw disjunction. (C) 2017 Sociedade Portuguesa de Estomatologia e Medicina Dentaria. Published by SPEMD.