Is the side with the best masticatory performance selected for chewing?

Objective This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex bag. Design Forty-two young adults with natural dentition participated in this cross-sectional, observational study. They performed four different masticatory assays, each consisting of five trials of chewing three pieces of silicon for 20 cycles. In one assay, they were asked to masticate unbagged silicon free-style, whilst in the three other assays they were asked to masticate bagged silicon free-style, unilaterally on the right-hand side and unilaterally on the left-hand side. The preferred chewing side was determined by calculating the asymmetry index for both the free-style assays. Masticatory performance was determined by sieving the silicon particles and the cycle duration was also recorded. Data were analysed using independent samples or paired t -test and linear regression. Results Masticatory function using the bagged silicon was similar to that using the unbagged silicon. A significant and positive relationship was observed between the preferred chewing side expressed as the asymmetry index and the side with better masticatory performance. Alternate unilateral chewers demonstrated better masticatory performance than unilateral chewers. However, when free-style and unilateral chewing were compared for each subject, unilateral chewing was found to be as efficient as – or even more efficient than – free-style chewing. Conclusions There is a positive association between the preferred chewing side and the more efficient side. Alternate unilateral mastication per se does not promote better masticatory performance than consistently unilateral mastication.