Occlusal support, denture use, and all-cause mortality in older adults: a large-scale Japanese claims-based cohort study

Diminished occlusal support has been associated with adverse health outcomes in older adults, but whether this association differs according to denture use remains unclear. We conducted a retrospective cohort study using a large-scale claims database in Japan. Individuals aged 65 years or older whose Eichner classification could be determined from dental claims were included. All-cause mortality was the outcome. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for age, sex, smoking, medication-based proxies for cardiometabolic conditions, comorbidities, outpatient visit frequency, hospitalization history, long-term care certification, denture use, and an interaction term between Eichner classification and denture use. Among 3,408,298 participants, 405,270 deaths occurred during 18,434,994 person-years of follow-up, with a median follow-up of 5.66 years. Compared with Eichner class A, the fully adjusted HRs for all-cause mortality were 1.26 (95% CI 1.25–1.27) for class B and 1.73 (95% CI 1.70–1.75) for class C. The association between denture use and mortality differed according to Eichner classification, with interaction HRs of 0.79 (95% CI 0.77–0.80) for class B and 0.66 (95% CI 0.65–0.67) for class C. Reduced occlusal support was associated with higher all-cause mortality, and lower mortality was observed among denture users in classes B and C. These findings should be interpreted as associations and do not establish a causal benefit of denture use.