Loss of Posterior Occlusal Support Is Associated With Incident Steatotic Liver Disease in a Nationwide Longitudinal Analysis of the JMDC Claims Database

AIM: Steatotic liver disease (SLD), including metabolic dysfunction-associated SLD (MASLD) and metabolic dysfunction-associated alcohol-related liver disease (MetALD), is a growing global health burden. Although impaired mastication is linked to metabolic disorders, its role in SLD remains unclear. We examined whether objectively assessed posterior occlusal support predicts incident MASLD and MetALD. METHODS: We analyzed nationwide medical, dental, and health checkup claims from the JMDC database in Japan (2016-2021), including 997,332 adults aged ≥ 40 years. SLD was defined as a fatty liver index ≥ 60, with MASLD and MetALD distinguished according to cardiometabolic abnormalities and estimated alcohol intake. Posterior occlusal support was classified using the Eichner system based on dental claims. Odds ratios (ORs) were estimated using generalized estimating equations to account for within-individual correlations, with multivariable adjustment for demographic, lifestyle, and clinical factors. RESULTS: Reduced posterior occlusal support was independently associated with higher odds of incident MASLD, with stronger associations in women. In fully adjusted models, women with partial (Eichner B) or absent (Eichner C) posterior support had higher odds of MASLD (OR 1.15, 95% CI 1.02-1.29; OR 1.55, 95% CI 1.11-2.16) than those with complete support (Eichner A). In men, the associations were weaker but remained significant. No robust association was observed between occlusal support and MetALD after adjustment. CONCLUSIONS: Loss of posterior occlusal support independently predicted MASLD, particularly in women, suggesting that impaired mastication may contribute to SLD.