Reduced Posterior Occlusal Contacts Are Associated With an Increased Risk of Stroke: A Retrospective Study Based on a Japanese Claims Database

BACKGROUND: Stroke remains a leading cause of mortality and disability worldwide, requiring modifiable risk factors for prevention. Oral health, particularly posterior occlusal contact that supports mastication, may influence systemic vascular outcomes; however, its role in stroke remains unclear. This study investigated whether reduced posterior occlusal contact independently predicts stroke in Japanese adults. METHODS: We conducted a retrospective cohort study using data collected from April 2016 to March 2022 from a nationwide health insurance database in Japan. Adults aged 40 to 74 years without a history of stroke were included. Posterior occlusal status was categorized as Eichner A (full posterior occlusal contact), B (partial contact), or C (no contact). The primary outcome was stroke incidence, identified using validated insurance claims. Cox proportional hazards models were used to estimate hazard ratios (HRs), adjusting for demographics, health behaviors, comorbidities, and tooth counts. RESULTS: =0.229). Associations were observed in both sexes and across age groups. CONCLUSIONS: Reduced posterior occlusal support was associated with higher stroke risk independent of tooth count and conventional vascular risk. These findings highlight that posterior occlusal support may represent a potential marker of cerebrovascular risk and warrant further investigation into its clinical relevance.