Evaluation of the use of surface electromyography in the diagnosis, documentation, and treatment of dental patients.

The use of electromyography as an aid in the differential diagnosis and treatment of dental patients is carefully examined in this literature review. Electromyography has been advocated for the establishment of rest and occlusal positions, and for the detection of muscle hyperactivity and hypoactivity, spasm, fatigue, and muscle imbalance. However, these claims were often based on studies that failed to include a control group when comparing various clinical parameters and EMG activity of the muscles of mastication. When a control group was incorporated, the authors usually failed to match the patients by such variables as age, sex, facial morphology, and history of bruxism. These variables have a significant influence on the level of EMG activity and may account for the high degree of variability observed between groups. Controlled trials evaluating the efficacy of biofeedback using electromyography found significant reductions of diurnal parafunctional activity during treatment, but the low symptom levels were not maintained after cessation of biofeedback. Based upon this extensive literature review, there is no convincing evidence to support the use of electromyography in the diagnosis or treatment of dental patients except in the treatment of parafunction.