Factors Associated with Number of Present Teeth in Adults in Japanese Urban City

The purpose of this study was to identify which factors were associated with number of present teeth (PT) in older adults as their clarification might contribute to maintaining the number of PT in this population. These factors were investigated by means of a questionnaire on oral health condition, general health behavior, and anamnesis of diabetes mellitus together with a dental examination. Data were obtained from a total of 7,741 Japanese subjects (2,623 males and 5,118 females), all of whom were aged 40, 50, or 60 years. Significant differences were observed in the mean number of PT between a positive or negative response to questions on anamnesis of diabetes mellitus, current smoking, and having loose teeth in all age groups in males; significant differences were also observed for current smoking, lower intake of dairy milk products, having loose teeth, no experience of tooth brushing instruction, and poor oral hygiene status in all age groups in females. Stepwise logistic regression analysis revealed having loose teeth (odds ratio [OR], 1.82), gingival swelling (OR, 1.40), an anamnesis of diabetes mellitus (OR, 1.72), current smoking (OR, 1.86), lower intake of dairy milk products (OR, 1.22), preference for salty seasonings (OR, 1.23), frequent sweet intake (OR, 1.29), no experience of tooth brushing instruction (OR, 1.38), and poor oral hygiene (OR, 2.04) as significant risk factors for the number of PT being <24 after adjusting for age and sex. These results indicate that an anamnesis of diabetes mellitus, a history of smoking, the presence of loose teeth, and poor oral hygiene status in a self-reported evaluation of oral health might correlate with <24 PT in older adults.