Relationship Between Frailty and Oral Function in Community‐Dwelling Elderly Adults

Objectives To determine the standard values of and age‐related changes in objective oral function of healthy older people; compare oral function of robust, prefrail, and frail older people; and determine the association between oral function and frailty. Design Cross‐sectional analysis. Setting General community. Participants Elderly adults (≥65) from the Obu Study of Health Promotion for the Elderly were included and assigned to the robust, prefrail, and frail groups (N = 4,720). Measurements Each participant underwent detailed physical testing to assess frailty. The frailty phenotype was defined according to the presence of limitations in three or more of the following five domains: mobility, strength, endurance, physical activity, and nutrition. The numbers of present teeth and functional teeth were counted, and occlusal force, masseter muscle thickness, and oral diadochokinesis (ODK) rate were measured, along with sociodemographic and functional status, comorbidities, and blood chemistry. Results The number of present teeth, occlusal force, masseter muscle thickness, and ODK rate decreased with age. The frail group had significantly fewer present teeth (women aged ≥70), lower occlusal force (women aged ≥70; men aged ≥80), lower masseter muscle thickness, and lower ODK rate than the robust group. Multivariate analysis indicated that age, Geriatric Depression Scale score, skeletal muscle mass index, Mini‐Mental State Examination score, hypertension, diabetes mellitus, albumin and triglyceride levels, and oral function were significantly associated with frailty. Conclusion Age‐related differences in oral function were found in older adults. Moreover, frail older individuals had significantly poorer oral function than prefrail and robust individuals. The risk of frailty was associated with lower occlusal force, masseter muscle thickness, and ODK rate.