auxism is most commonly defined as nonfunctional jaw movements that include clenching, grinding, gritting, gnashing, and clicking of teeth. The condition is believed to be emotionally based and may lead to destructive changes in one or more components of the masticatory system. It may also include the contact of teeth during the chewing of cheeks, lips, pencils, and pipes. It may be performed consciously or unconsciously. This dysfunction is similar to many psychophysiologic disorders in that physical, psychologic, and neurophysiologic factors may interact in contributing to the problem behavior. Bruxism that produces a musculoskeletal pain disorder is believed to be a result of excessive muscle activity. Experimental studies support the relationship between hyperactive muscle contraction caused by bruxism and pain.’ Measurement of the bruxing activity in the patient’s environment is necessary to verify these studies and results. Reports on the occurrence and prevalence of bruxism vary widelyzm8 and attempts to describe the etiology of bruxism9~‘o have failed to do so compellingly. Common treatment approaches for bruxism have included pharmacotherapy and splint therapy. The use of muscle-relaxing and tranquilizing medications as a means to control bruxism was first suggested by Chasins.” It has been suggested, however, that chemotherapy may be the least effective of the tension-reducing techniques. Davidson et a1.12 found that subjects who attributed improvement to self-controlled relaxation and other self-control devices maintained their gains longer than those who attributed their gains to drugs. The standard dental treatment for bruxism is an intraoral splint. Solberg and Rugh13 recorded electromyograph (EMG) levels of muscle activity before, during, and after splint treatment. Occlusal splints dramatically reduced muscle activity during the treatment period, but after splint wear was discontinued, muscular activity rose to