Survey of bruxism in an institutionalized mentally retarded population.

Bruxism was assessed in a population of 358 institutionalized mentally retarded individuals using two independent indexes: toothwear and staff reports. Bruxism based upon toothwear was found in 58%. Bruxism identified by staff reports was found in 41% of the population. No sex differences were observed. Three bruxer subgroups were identified: daytime only (17%), night only (8%), and day and night (16%). Older residents were more likely to grind their teeth than were younger residents. These results, when compared with other reports, suggest that bruxism is more likely to occur in the institutionalized mentally retarded population than in the nonretarded population.