Relationship between Subjective Oral Health Status and Lifestyle in Elderly People: A Cross-Sectional Study in Japan

Objective. The aim of this study was to assess the relationship between subjective oral health status and lifestyle in elderly people living in Japan. Methods. Subjects were 5383 inhabitants of the Kagawa Prefecture, Japan, at the age of 75–100. Records of the number of remaining teeth and the data from self-reported questionnaire were analyzed statistically. Results. Remaining teeth were significantly correlated to “no current smoking,” while not related to other lifestyle. On the other hand, “subjective masticatory ability” defined as a condition allowing chewing all foods well was related to favorable lifestyles. “Subjective masticatory ability” was also related to “not feeling stress,” “no deviated food habit” as well as to other good oral health conditions. A logistic regression analysis for “remaining teeth more than 20” revealed a significant relationship between “no current smoking” (OR？=？1.582) and “no alcohol drinking” (OR？=？0.851). Regarding “subjective masticatory ability,” all favorable lifestyles analyzed in this study were found to be significant positive factors. Conclusions. “Subjective masticatory ability” seems to be strongly associated with favorable lifestyles. Therefore, it can be suggested that “subjective masticatory ability” might be a good landmark for quality of life of elderly people in addition to the number of remaining teeth. 1. Introduction From the time the “8020 Movement” was proposed by Japan Dental Association and approved by the Japanese Ministry of Health and Welfare in 1989 in Japan; the concept that maintaining more than 20 teeth at 80 years old leads to healthy and long life has been recognized throughout the country. Several studies conducted with “8020 achievers” reported that “8020 achievers” are better than “8020 nonachievers” for not only masticatory ability but also general physical conditions, including bone mineral density (BMI), grip strength, and the duration of balance test [1]. The food intake survey demonstrated that the “8020 achievers” ate a larger variety of food, although these foods were with less kilocalories and lower levels of carbohydrate [2]. Several epidemiological studies showed that the number of remaining teeth is closely related with smoking habit [3, 4] and with education level [4, 5]. A study investigating the masticatory ability of elderly people reported that “objective masticatory ability” was related significantly to “tooth loss less than 10” and “subjective evaluation that I can chew all foods well” [6]. This study also demonstrated that the masticatory ability of elderly people