Factors of Elderly People that Have More Than 20 Teeth : Case-control Study in the Eastern Region of Hokkaido Prefecture

More than 20 years have elapsed since Japan promoted the 8020 campaign (that 80-year-old people should have more than 20 teeth); however, most 80-year-old people still have fewer than 20 teeth. This study surveyed people of 65 years of age or older in the eastern region of Hokkaido Prefecture, Japan regarding the risk factors associated with elderly people having less than 20 teeth. Additionally, this is studied less well in Hokkaido. The study subjects were 85 elderly people (60 men and 25 women: who were given an award at an elderly good teeth contest in 2010) who had more than 20 teeth, as well as 79 elderly people (19 men and 60 women: who had participated in a dental examination by a public relations magazine in 2005) who had fewer than 20 teeth. The survey items used were age, sex, height, weight, history of systematic disease, experience of smoking, experience of alcohol drinking, physical activities when young, exercise, eating frequency of past and current foods, oral health behavior, and so on (38 items). Odds ratios (ORs) and their 95% confidence interval (95%CI) of various variables related to the number of present teeth were evaluated using univariate analysis by employing the unconditional logistic regression model by sex and multivariate analysis using a stepwise procedure by sex. The results of the univariate analysis were as follows: Males with fewer than 20 teeth had significant factors such as being aged 78 years or more (OR=8.00, 95%CI: 2.10-30.46), having a systematic disease (OR=4.95, 95%CI: 1.29-18.98), a walking time of less than 5 hours per day due to work and so on when young (OR=0.22, 95%CI: 0.07-0.66), alcohol drinking more than or equal to once a week (OR=0.21, 95%CI: 0.06-0.71), less frequent intake of vegetables (OR=2.99, 95%CI: 1.03-8.69), less frequent intake of processed foods (OR=3.21, 95%CI: 1.11-9.31), having no personal dentist (OR=10.21, 95%CI: 3.06-34.08), and no use of dental floss and an interdental brush (OR=9.14, 95%CI: 1.08-77.68). Females with fewer than 20 teeth had significant factors such as a high BMI (OR=3.42, 95%CI: 1.27-9.19), having a systematic disease (OR=7.57, 95%CI: 2.40-23.88), doing less than half an hour of exercise a day (OR=40.00, 95%CI: 8.20-195.22), less frequent intake of vegetables (OR=0.36, 95%CI: 0.14-0.96), less frequent intake of vinegar dishes (OR=0.36, 95%CI: 0.13-0.98), not taking vitamin supplements (OR=4.50, 95%CI: 1.36-14.89), having no personal dentist (OR=6.66, 95%CI: 1.43-30.97), and no use of dental floss and an interdental brush (OR=6.44, 95%CI: 2.08-19.97). The results of the multivariate analysis were as follows: Males with fewer than 20 teeth had significant factors such as being aged 78 years or more (OR=12.78, 95%CI: 1.92-85.02), alcohol drinking more than or equal to once a week (OR=0.09, 95%CI: 0.01-0.71), less frequent intake of processed foods (OR=6.48, 95%CI: 1.03-40.57), and having no personal dentist (OR=17.04, 95%CI: 2.21-131.75). Females with fewer than 20 teeth had significant factors such as a high BMI (OR=13.82, 95%CI: 1.21-157.50), doing less than half an hour of exercise a day (OR=41.30, 95%CI: 3.87-441.19), and no use of dental floss and an interdental brush (OR=16.31, 95%CI: 1.40-189.67). We need to highlight that these results are available for health promotion planning for the municipality in the eastern region of Hokkaido Prefecture.