Deglutition pattern in Angle’s Class II malocclusion

ABSTRACT Purpose: to analyze the electromyographic activity of the suprahyoid muscles during deglutition in participants with Angle´s Class II malocclusion. Methods: electromyographic data recordings were performed in the supra-hyoid muscles during swallowing and at rest, in 30 volunteers, 15 Angle´s Class I participants and 15 Angle´s Class II malocclusion, aged 15-27 years old. The Root Means Square values for both tests were analyzed, and for the deglutition test, the Linear Envelope was used to observe the type of muscle activation pattern. Results: during the test at rest, there was no significant difference in Root Means Square values (p=0.22) between Class I and Class II subjects. During deglutition, it was found that Angle´s Class II subjects had significantly higher RMS values (p=0.01) as compared to Class I volunteers. Regarding the type of muscle activation pattern, there was a significant difference between Class I and Class II participants with a predominance of type 1 peak for Class I and type 2 peak for Class II. Conclusion: there was a difference in electromyographic recordings during deglutition in participants with Angle´s Class II as compared to Class I participants with a tendency towards two contraction peaks, showing a greater imbalance during the function. There was no difference between groups in the rest position.