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.

摘要
目的：分析安氏Ⅱ类错牙合畸形受试者吞咽过程中舌骨上肌群的肌电活动。
方法：招募30名年龄介于15~27岁的志愿者开展肌电数据采集，其中安氏Ⅰ类错牙合畸形受试者15名，安氏Ⅱ类错牙合畸形受试者15名；分别于静息状态及吞咽过程中对舌骨上肌群进行肌电记录。对两次测试的均方根（Root Means Square, RMS）值进行分析，并采用线性包络（Linear Envelope）观察吞咽测试中的肌肉激活模式类型。
结果：静息状态下，安氏Ⅰ类与Ⅱ类受试者的均方根值无显著差异（p=0.22）。吞咽过程中，安氏Ⅱ类受试者的均方根值显著高于安氏Ⅰ类志愿者（p=0.01）。在肌肉激活模式类型方面，两组间存在显著差异：安氏Ⅰ类受试者以1型峰为主，安氏Ⅱ类受试者则以2型峰为主。
结论：与安氏Ⅰ类受试者相比，安氏Ⅱ类受试者吞咽过程中的肌电记录存在差异，其肌肉收缩多呈现双峰值趋势，提示该群体吞咽功能失衡程度更高；静息状态下两组受试者无显著差异。