Psychological stress in orofacial neuromuscular problems.

Several forms of treatment for orofacial neuromuscular problems are based on the hypothesis that muscle hyperactivity due to psychological stress is a key factor in the aetiology. This paper reviews the evidence for this belief and describes the results of a study of muscular activity over a prolonged period by means of a portable battery powered electromyographic recording apparatus. In earlier studies of nocturnal masseter muscle activity ther was found a correlation between nocturnal bruxism and reports of stress. More recent studies covering activity for 24 hours per day have suggested that periods of muscle hyperactivity are correlated with specific daily activities but that there is great variability between patients. It is not yet possible to determine whether the patient's report of anxiety is the result or the cause of the orofacial muscular pain problem. It is evident that other parameters require evaluation.