Standardised Surface Electromyography During Clenching and Swallowing: Patient Perception and Comparison of Two...

To compare standardised surface electromyography (ssEMG) data and patient perception between two EMG standardisation methods for clenching (cotton rolls vs. wax pads) and swallowing (with vs. without an air-filled bulb). The third aim was to analyse ssEMG data during saliva swallowing to detect differences among masseter (MM), temporalis (TM) and submental (SM) activity.

Electromyographic data were obtained from 45 participants after clenching tests with wax pads and cotton rolls, and swallowing tests with and without an air bulb. Participants rated comfort, quickness, and stress of each modality on a 10-point Likert scale. TM, MM and SM activities were recorded using ssEMG indices. Clenching and swallowing data were compared using the Student's t-test. A one-way ANOVA was used to assess muscle roles during saliva swallowing. Perception scores were compared with the Student's t-test.

Forty-five participants (37 women, mean age 22.75 ± 1.27 years) were included. No differences emerged between ssEMG indices during clenching and swallowing, except for the IMPACT index of MM (p < 0.001) and TM (p < 0.01), both lower with wax. No perception differences were found between wax and cotton roll clenching. Swallowing with an air bulb was rated as more comfortable (p < 0.001) and less stressful (p < 0.05). During swallowing, SM showed significantly higher activity and longer duration (p < 0.001) than TM and MM.

Both cotton rolls and wax pads are suitable for clenching standardisation, though wax may reduce TM and MM activity. For swallowing, the air-filled bulb does not affect ssEMG indices but is perceived as more comfortable and less stressful.