Synchronization of masseter activity patterns between the right and left sides during chewing in healthy young males

Abstract

Masseter activity patterns during chewing, which were quantitatively assessed using T₅₀ values, were compared between the right and left sides of healthy young males. Surface electromyograms were recorded from both masseters, and each participant was asked to chew four different agar samples at his own pace across two separate sessions. The four agar samples, each possessing differing textural properties, consisted of two normal and two distinctive agar varieties. The Pearson’s correlation coefficient was calculated for each pair of T₅₀ values to evaluate the degree of synchronization of activity patterns between both masseters. A three-way analysis of variance revealed significant main effects of the ‘participant’ and ‘experimental session’ factors, but not of the ‘test food’. The number of significant coefficients increased stepwise by increasing the number of chews per sequence. These results suggest the importance of the initial stages of chewing sequences in facilitating the synchronization of bilateral masseter activity patterns.

• Activity pattern
• adult
• chewing side
• masseter

Acknowledgements

This study was supported in part by the Grants-in-Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (No. 22500740 to YM, No. 23700889 to TY, and No. 2050072 to IA).