[Nocturnal sleep studies of bruxism].

Polygraphic recordings during two nights sleep in 7 selected outpatients prior to and following treatment of bruxism were carried out using EMG-, EEG and EOG-recordings to evaluate the activities of the masseter muscle and the different sleep stages. The results thus obtained were compared to those of an age-matched control group. Following treatment with occlusal splints the recordings were repeated eleven weeks later. The length and the amount of grinding and pressing activities were correlated with the total night sleep as well as with the different sleep stages. The highest incidence of muscle activity was found in stage two and during awakening. Furthermore muscle activities were observed immediately before the beginning of REM-sleep and in particular during the change from REM- to NREM-sleep and in sleep stage one. After treatment with occlusal splints there was a decrease of total muscle activity, thus indicating efficiency of the treatment.