Contribution of dental prostheses on the association between dental visits and self- reported chewing ability among older Japanese adults: a cross-sectional study.

BACKGROUND: Dental treatment restores chewing ability among those with fewer teeth. However, few studies have evaluated the impact of dental visits on chewing ability. This study examined the mediating effect of dental prosthetic treatment for missing teeth on the association between dental visits and self-reported chewing ability in Japan, where national health insurance covers most of the basic prosthetic treatments. METHODS: This cross-sectional study used data from the Japan Gerontological Evaluation Study. Self-reported questionnaires were distributed to older adults aged ≥ 65 years in 2022. The present analysis included those who answered the dental visit questionnaire and had ≤ 19 remaining teeth. The presence or absence of dental visits within one year was used as an explanatory variable, while the dental prosthetic treatments for missing teeth and the self-reported chewing ability were used as mediator and outcome, respectively. A causal mediation analysis was applied with possible confounders, including socioeconomic status. RESULTS: Among 8,441 respondents, good chewing ability was reported by 56.3% of those who visited the dentist and 49.9% of those who did not visit the dentist within the past year. On mediation analysis, the dental prosthetic treatments accounted for 59.0% of the association between dental visits and good chewing ability (natural indirect effect, odds ratio = 1.25 [95% confidence interval: 1.18–1.33]). CONCLUSIONS: Although this cross-sectional study could not determine causality, reasonable association, dental visits were associated with better chewing ability through the dental prosthetic treatments for missing teeth, was suggested.