[Objective examination and diagnosis of bruxism. 1. New device for recording muscle activity and tooth contacts during sleeping at home].
The purpose of this study was to make an objective diagnosis of bruxism using a new recording system by observation during sleeping at home. The system was composed of a portable recorder for monitoring bruxism at home and an analyzing device for recalling the data later in laboratory. Muscle activity as recorded by EMG, occlusal tooth contacts were monitored by microvibration pick-up, and grinding sounds were recorded by a small microphone, simultaneously. These were printed on the one recording paper by playing back the tape. Six subjects were selected and were monitored individually for five nights with this new system at home. Records were transcribed and analyzed in the laboratory. As a result, nocturnal muscle activity, occlusal tooth contacts, and grinding sounds were recorded and analyzed efficiently with system. This new system is considered in useful for the investigation and diagnosis of bruxism in periodontal disease.