Electrical activity of masseter muscle in young adults during swallowing of liquid.

PURPOSE To characterize the electrical activity of the masseter muscle during swallowing of liquids in healthy young adults. METHODS Participants were 14 volunteers considered healthy according to the inclusion and exclusion criteria established for this study. The bilateral electromyographic evaluation of the masseter muscle was conducted at rest and in swallowing tasks of 14.5 ml, 20 ml and 100 ml of liquid. The electromyographic signal was normalized by the maximum voluntary activity resisted (MVAR), considered as 100% of the muscle's electrical activity. RESULTS In the right masseter, the highest average percentage was found in the 20 ml task, and in the left masseter, in the 14.5 ml task. In the right masseter there was difference between the 14.5 ml and the 20 ml swallowing tasks. In the left masseter, no differences were found between the swallowing tasks. CONCLUSION The electrical activity of the masseter muscle in healthy young adults during deglutition of liquids can be influenced by volume swallowed, and present different responses bilaterally.