Difference between Right and Left Facial Surface Electromyography in Healthy People.

INTRODUCTION: The study was to see whether there were differences in values of facial surface electromyography in subjects of good heath by muscles, age, and sex. METHODS: It draws ratio between lower value and higher value (R-LV/HV) and asymmetry index (AI), based on root mean square (RMS) from measurement of facial surface electromyography (sEMG) in 154 people of healthy people (male:female = 70:84) aging between more than 20 and less than 70. RESULTS: For R-LV/HV, it averages 81.70±14.60% on frontalis muscle, 73.74±19.12% on zygomaticus muscle, and 79.72±14.77% on orbicularis oris muscle. With analysis of the AI average was 10.87±10.14% on frontalis muscle, 16.71±14.79% on zygomaticus muscle, and 12.10±10.05% on orbicularis oris muscle. Both values were statistically significant in three parts of muscles as shown. Both of R-LV/HV and AI show no statistically significant difference on age and sex (p>0.05). CONCLUSIONS: It could provide basic data for the future diagnosis of facial nerve palsy patients by measuring facial sEMG values for healthy people.

Development of electromyographic indicators for the diagnosis of temporomandibular disorders: a protocol for an assessor-blinded cross-sectional study.

BACKGROUND: Noninvasive and easy-to-use surface electromyography (EMG) is frequently utilized for the diagnosis of temporomandibular disorders (TMDs). However, few EMG parameters that consider TMDs in addition to the cranio-cervical-mandibular system have been regarded as important in traditional Korean medicine. METHODS: This clinical trial will be conducted as an assessor-blinded cross-sectional study. The participants will be classified based on the Diagnostic Criteria for TMDs Symptom Questionnaire (DC/TMD SQ) and 30 TMD patients and 30 healthy controls will be enrolled. The primary outcome will be the percentage overlapping coefficient (POC; %) in the masseter and sternocleidomastoid muscles between the patient group and healthy control group in clenching and cervical side flexion. The secondary outcomes include the score from temporomandibular joint-related questionnaires, the difference in the absolute values of EMG for the healthy group and TMD group before/after wearing intraoral appliances, and the change in the location of the temporomandibular joint as determined by X-ray imaging and 3D face photography. DISCUSSION: This study will provide information about the objective diagnostic method for TMD using surface EMG and will verify the effectiveness of surface EMG in diagnosing TMD. Furthermore, the method or device for diagnosis TMD will improve the expansion of treatment area to TMD by accumulating evidence for the efficacy of TKM treatment.