Lack of posterior occlusal support predicts the reduction in walking speed in 80-year-old Japanese adults: A 3-year prospective cohort study with propensity score analysis by the SONIC Study Group

Objective: To investigate the association between posterior occlusal support by residual teeth and the reduction in walking speed in 80-year-old Japanese adults using propensity score matching. Background data discussing the present status of the field: Previous studies have demonstrated an association between oral status and motor function; however, most of these studies had a cross-sectional design. Material and method: This study included 353 community-dwelling Japanese people aged 79-81 years. Low walking speed was defined as ≤0.8 m/s, and participants with a low walking speed at baseline were excluded. The participants were divided into two groups: with or without posterior occlusal support by residual teeth at baseline. Propensity score matching was used to reduce the effects of bias by matching participants with and without posterior occlusal support according to similar background factors at baseline. Conditional logistic regression was conducted to determine low walking speed at the 3-year follow-up, which included posterior occlusal support as an independent variable with matching data. Results: Before matching for posterior occlusal support, significant differences existed between the groups in terms of sex, years of education, height, weight and grip strength. However, after matching, there was no significant difference between the groups in any characteristic. Logistic regression analysis showed that posterior occlusal support is a significant variable (odds ratio = 1.88; P = 0.04) associated with reduced walking speed. Conclusion: Lack of posterior occlusal support at baseline independently predicted the incidence of reduced walking speed over 3 years.