Functional Occlusal Support, Denture‐Related Status and Hip Fracture Risk in Older Adults: A Large Claims‐Based Cohort Study

PURPOSE: To examine whether reduced functional occlusal support is associated with incident hip fracture in older adults and whether this association varies according to denture-related status. METHODS: We conducted a retrospective cohort study using a large administrative claims database in Japan. Adults aged 65 years or older with baseline tooth-chart information and no prior hip fracture were included. Functional occlusal support was classified using the Eichner classification, a prosthodontically relevant measure of posterior occlusal support. The primary outcome was incident hip fracture identified from medical claims. Cox proportional hazards models were used with sequential adjustment for demographic characteristics, osteoporosis-related factors, neurologic and vascular comorbidities, and hospitalization history. Additional analyses included piecewise Cox models by follow-up interval and a 1-year landmark analysis. RESULTS: Among 3 349 245 participants, lower functional occlusal support was associated with a higher risk of hip fracture. In the fully adjusted model, hazard ratios were 1.21 for Eichner class B and 1.44 for class C, compared with class A. The association varied according to denture-related status, with significant interaction terms for class B and class C. Findings were broadly consistent in time-interval and landmark analyses. Median follow-up was 5.66 years, during which 93 921 hip fractures occurred, corresponding to an overall incidence rate of 5.17 per 1000 person-years. CONCLUSIONS: Reduced functional occlusal support was associated with a higher risk of hip fracture in older adults. These findings suggest that prosthodontically relevant functional oral status may have clinical significance beyond oral outcomes alone, although causal interpretation is limited in claims-based observational data.