[An epidemiological study of the relationship between the number of remaining teeth and the disabled elderly receiving long-term care].

This study attempts to clarify the relationship between the long-term care of the elderly and the number of remaining teeth by comparing the remaining teeth of the healthy with that of the disabled elderly. A survey was conducted in a town, Fukuoka Prefecture. The disabled group consisted of 62 persons with level of disability of 4-5 according to the Long-term Care Insurance categorization. Controls were selected randomly from healthy elderly residents, one for each in the disabled group, matching gender and age (less than +/- 1 year old). Public health nurses conducted interviews using a questionnaire to determine the cause of disease, medical history, lifestyle and period of long-term care, and counted the remaining teeth. The mean number of remaining teeth presented a significant difference with 3.7 for the disabled group and 9.1 for the control group (p < 0.01). A logistic regression analysis revealed that the odds ratio for long-term care to that of the reference with 20 or more teeth was 7.03 (95% CI: 1.15-42.85) for 10 to 19 teeth, 15.61 (2.89-84.26) for 1 to 9 teeth, and 15.11 (2.84-80.48) for no teeth. The age group of 65-69 years and 70-79 years in the disabled group had significantly smaller mean numbers of remaining teeth than their control group counterparts by approximately 14 and 12 respectively, but in the age group of 80 years or more, no significant difference was observed between the two groups. In conclusion, our results suggested that elderly people with fewer remaining teeth have a high risk for long-term care. Especially, the risk was thought to be strongly associated with the loss of some teeth in middle age.