A highly significant reduction in bruxism has been obtained using a biofeedback system. The concept that the etiology of bruxism is related to emotional stress is supported as biofeedback has been successful in controlling other stress-related parameters. The form of biofeedback used as an audible tone derived from amplified electromyographic data, relayed to the subject via an earpiece. Future work will be concerned with learning potential and the control of parafunctional activity; further investigation into the correlation between E.E.G. patterns and masticatory E.M.G. activity is necessary.