Influence of occlusal deterioration considering prosthetics on subsequent all‐cause mortality in a Japanese elderly independent population

Purpose The influence of occlusal deterioration on mortality may be incorrectly estimated due to improvements in the occlusal condition with prosthetics or deterioration without prosthetics. The purpose of this study was to evaluate the influence of occlusion cross‐sectional status and longitudinal changes considering prosthetics for subsequent all‐cause mortality in an elderly population. Methods Two dental examinations, in 1999 and 2003, were conducted in 378 subjects aged 71 years old in 1999. Annual follow‐ups to check survival information were performed until 2011. The Eichner index (EI), based on tooth contacts between the maxilla and mandible in the bilateral molar regions, was used as a measurement of occlusal condition. Three modified EIs, EI‐o (ie, original EI), EI‐f adding contacts by fixed prosthetic appliances, and EI‐r adding contacts by all prosthetics, were used. For survival analysis, the survival period was calculated from the last dental examination (in 2003) to death or censoring. Results In Cox proportional hazards regression analysis, a deterioration in EI‐f was a significant risk factor for stability (HR = 2.56, P = 0.018) after adjusting for potential confounders. However, occlusal conditions in 2003 did not have an influence on subsequent mortality and the occlusal losses of almost all subjects were at least partially recovered by removable prosthetics. Conclusion This study clarified that prosthetic dental care may reduce the influence of occlusal loss on mortality and that an event such as a large occlusal loss unrecoverable with fixed prosthesis alone at an older age may increase risk of death in Japanese elderly subjects.