Electrical activity of the masseter during swallowing after total laryngectomy

Total laryngectomy is a surgical procedure that can change swallowing biomechanics, including muscle activity of the masseter; this muscle stabilizes the mandible. Aim: To characterize the electrical activity of the masseter muscle during swallowing after total laryngectomy. Series study. Material and Methods: An electromyographic evaluation of swallowing was carried out; three different volumes of water (14.5ml, 20ml and 100ml) were swallowed, and there was a rest condition. The electromyographic signal was normalized by Maximum Resisted Voluntary Activity - considered as 100% of electrical activity of muscles. All other values were calculated as a percentage of this parameter. Results: There is moderate electrical activity of the masseter during swallowing with higher averages on the left. There was no difference between swallowing 14.5ml or 20ml. Natural swallowing of 100ml had the lowest average. Electromyographic signals were recorded at rest on both sides, indicating the existence of electric activity in this situation. Conclusion: Patients submitted to total laryngectomy present electrical activity of the masseter muscles during swallowing and at rest. This activity is influenced by the volume of swallowed liquid, and showed significant differences among the tasks.