Jaw Movement and Orofacial Muscle Activity During Singing
Yu-Yao Chang, Lander Manrique, Sara Hashemi, Theodora Nestorova, John Mac Master, Isabelle Cossette, Svetlana Komarova, Carolina Meloto, Elizabeth Zimmermann
Background: Five to twelve percent of adults live with painful temporomandibular disorder (pTMD) that affects the temporomandibular joints and/or the masticatory muscles. Jaw overuse is associated
with increased risk of pTMD. Singers are considered to be at risk of jaw overuse; however, recent studies have shown that singing is not associated with pTMD. Singers are occupational users of their head and neck; they are trained to precisely control the position of their jaw, lips and tongue and reduce muscle tension. It is unknown whether singing-related muscle and movement patterns are beneficial for oral health.
Objective: Here, we aim to investigate how singers and non-singers with and without painful TMD use their jaw and activate their masticatory muscles. My research has created a protocol and a data
analysis routine for surface electromyography (sEMG) and motion capture data.
Methods: We aim to recruit four groups: singers with pTMD, singers without pTMD, non-singers with pTMD and non-singers without pTMD. Reflective markers and surface electromyographic (sEMG) sensors are placed on the face. Each participant performs jaw range of motion (ROM), speaking and singing tasks. During each task, sEMG, motion capture and audio data are acquired simultaneously. The data are processed using a customized Matlab script and application.
Results Thus, far we have created a data analysis routine that automatically separates the data into each task and then measures for each task mean muscle activity (normalized to maximum voluntary
contraction), maximum jaw opening, mandibular rotation and mandibular translation. The expected results of the study are that singers are trained to control the position of their jaws and reduce facial tension, leading to differences in muscle activity and jaw movement in singers compared to non-singers during speaking and singing tasks.
Conclusion: This study aims to understand whether singers have different muscle activity and jaw movements than non-singers. Singing could be a potential therapy for pTMD to promote physical exercise of the jaw as well as psychological benefits. More research is required in this domain to understand the role of singing on oral health.