Effect of habitual chewing side on masticatory function

Abstract

Purpose: The purpose of this study was to elucidate the effect of the habitual chewing side on masticatory performance by examining the functional difference between chewing on the habitual and the non-habitual chewing sides. Methods: Ten asymptomatic subjects (ages 26-33 years, mean age 28.7 years) who participated in the 7^th seminar of the Japanese Society of Stomatognathic Function were included in this study. The stability of masticatory path and rhythm and the patterns of masticatory movement path were compared between the habitual chewing side and the non-habitual chewing side during gum chewing. The glucose extraction as the indicator for masticatory function was compared between the two sides. Results: The values of the three indicators representing the stability of masticatory path and rhythm on the habitual chewing side were smaller compared to those on the non-habitual chewing side in 6 of 10 subjects. The glucose extraction on the habitual chewing side was significantly larger than that on the non-habitual chewing side. The majority of subjects, 8 of 10 subjects, showed Pattern I and Pattern III during chewing on the habitual chewing side. When the frequent pattern on the two sides was scored in order to evaluate quantitatively the stability of masticatory movement, the score for the habitual chewing side was larger than it for the non-habitual chewing side in 5 of 10 subjects, and the scores on the two sides were equal in 3 of 10 subjects. Conclusion: The present results suggested the following possibility: 1. Functional differences were found between chewing on the habitual chewing side and chewing on the non-habitual chewing side. Moreover, it was concluded that masticatory performance for chewing on the habitual chewing side was superior to it for chewing on the non-habitual chewing side. 2. Measurement of the glucose extraction as the indicator for ability of mastication, the pattern of masticatory movement path and the stability of masticatory path and rhythm (the values of the indicators representing the stability of masticatory path and rhythm) were useful for the quantitative evaluation of masticatory performance.