Electromyographic analysis of the masseter and suprahyoid muscles in the oral phase of swallowing in healthy adult individuals

Abstract

Objective: to evaluate by means of electromyographic analysis of the masseter and suprahyoid muscles the oral phase of the swallowing of different volumes of saliva and liquid in healthy adult individuals. Material and Methods: the method consisted in analyzing samples of three swallowing trials: voluntary and single swallow of saliva (dry), voluntary and single swallow of 10 ml of water, and voluntary and single swallow of 20ml of water. Statistical analysis: Through Friedman’s ANOVA test we observed a significant variation in the medium potential of the right suprahyoid muscle (p=0.010) when compared to the left suprahyoid muscle (p=0.05). Other correlations were verified by using the Nemenyi test, the Wilcoxon test and the Spearman coefficient to support the different analyses of the results. Results: the analysis found a direct relation between the electrical activity of the masseter and suprahyoid muscles when swallowing 20 ml water as regards the highest potential values, irrespective of face side – left or right; i.e., when swallowing 20ml water, the higher the potential of one muscle group, the higher the expected value of its antagonist. Conclusion: the electromyographic behavior of the masseter and suprahyoid muscles during voluntary swallowing of saliva and two standardized liquid volumes showed that the electrical activity of the masseter muscles did not vary according to the type of swallowing.