Masseter muscle surface electromyography in college students with a high degree of anxiety and temporomandibular disorder

ABSTRACT Objective: to compare the electrical activity of masseter muscles, bilaterally, according to the presence or absence of Temporomandibular Disorder (TMD) in college students with a high degree of anxiety. Methods: the study was conducted with a randomized sample of 31 Speech Therapy students aged between 17 and 32 years; 61.3% (n = 19) were females and 38.7% (n = 12) were males. They were divided into two groups, Group 1 (G1), comprising 11 students with TMD, and Group 2 (G2), composed of 20 students without TMD. The college students answered the State-Trait Anxiety Inventory (STAI) for anxiety investigation, and were evaluated by the protocol Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) for TMD diagnosis. The evaluation of muscular electrical activity took into account the records in the conditions of rest, Sustained Maximum Voluntary Activity (SMVA) and habitual chewing (HC). The data were analyzed using the version 22 IBM Statistical Package for Social Sciences (SPSS) software. The statistical analysis was performed using Student t test to compare means between groups, considering < 0,05 as the significant p-value. Results: college students, of both groups, presented high levels of anxiety traits. Significant statistical differences were observed on the percentage of electrical activity of right masseter muscle in chewing function, as well as muscle fibers recruitment during chewing, which were higher on the group without TMD. Conclusion: college students with TMD and a high degree of anxiety presented lower means of masseter muscle electromyografic activity during chewing, in most conditions assessed, as compared to volunteers without TMD, except for the left masseter muscle in rest and chewing.