Electromyographic changes in masseter and sternocleidomastoid muscles can be applied to diagnose of temporomandibular disorders: An observational study

BACKGROUND: The diagnosis of temporomandibular disorders (TMDs) is an important part of the functional cerebrospinal technique (FCST). In addition, surface electromyography (sEMG) is an important candidate for diagnosing TMD. In FCST, despite the importance of the cranio-cervical-mandibular system, few sEMG parameters consider TMDs. Thus, this study evaluated the possibility of TMD diagnosis by sEMG. METHODS: The study was conducted as an assessor-blinded cross-sectional study. Each of 35 participants were recruited for patient group and normal group separately based on the Diagnostic Criteria for TMD Symptoms Questionnaire (DC/TMD SQ). The sEMG was measured by attaching electrodes to sternocleidomastoid muscles (SCMM) and masseter muscles (MM) before and after wearing the temporomandibular joint balance appliance (TBA). RESULTS: The percentage overlapping coefficient (POC) value of the healthy control group was increased compared with the TMD group. Receiver operating characteristic (ROC) analysis revealed that the area under the curve (AUC) value of the SCMM was greater than that of the MM. POC values before and after the SCMM also revealed significant changes compared to the MM. CONCLUSION: This study showed that the sEMG measurement of the SCMM is useful for TMD diagnosis in traditional Korean medicine.