Evaluation and Factor Analysis of Oral Hygiene Status in Institutionalized Mental Retardates with Ramfjord Plaque Index

Epidemiological analyses using the Ramfjord Plaque Index (PI) were performed on 881 mental retardates possessing one or more subject teeth at 15-48 years of age. They were among a group of 1107 subjects who were admitted to the Niigata Prefectural Institute of Total Training for the Mentally Retarded, Colony Niigata Shiroiwa-no-Sato, during the years 1971-1988. The personal rates classified by maximum PI score and average number of sextants per person according to PI grades were compared, with regard to the attributes supposed to be an influential factor, and 3 periods of admission, the years 1971-1975, 1976-1981 and 1982-1988. There was a difference in oral hygiene status between males and females in the first half of the 1970's, but toward the 1980's the oral hygiene status of male newcomers had improved, and this difference disappeared. It appeared that there was no difference between profoundly to severely retarded and moderately retarded or between histories of non-institutionalization or institutionalization before admission. No difference among adimission periods was recognized in oral hygiene status of females.