Effects of tooth loss on functional impairment in elderly: A secondary data analysis of elderly cohort in the South Korea.

Introduction: This study aimed to assess the association of tooth loss with physical and cognitive impairments in the elderly aged over 65 years.

Methods: The Elderly Cohort database (2008-2013) of National Health Insurance Services in South Korea was used; 1485 individuals who underwent physical impairment evaluation and 1410 individuals who underwent cognitive impairment evaluation were analysed. The dependent variables were the standardized physical and cognitive function score. The generalized estimating equation method was used for repeated measures. The total number of teeth lost during the study period, sex, age, Charlson comorbidity index, income, medical aid, long-term care facility residence, living alone, and long-term care beneficiary was used as covariates.

Results: Differences between the baseline and endpoint standardized function scores of the participants with impaired physical function and impaired cognitive function were 13.6 and 20.1, respectively. The magnitude of functional impairment due to tooth loss was greater for cognitive function than for physical function. The number of teeth lost was associated with approximately 1.4- and 1.7-point decrease in physical and cognitive functions, respectively (both p < 0.001).

Conclusions: These findings suggest that the oral health status is essential for maintaining physical and cognitive functions and that oral health services can be effective in delaying functional impairment among the elderly residing in coordinated long-term care facilities.