Link between tooth loss and health expectancy: findings from a prospective Singaporean population-based cohort study of older adults

BACKGROUND: We evaluated the impact of the number of teeth on health expectancy, measured as years of life without limitations in activities of daily living (ADLs) and physical function, among adults aged ≥60 years. METHODS: Data from 3384 older adults in a nationally representative longitudinal study in Singapore were analysed. Health expectancy was estimated using an inverse probability-weighted multistate life table approach with microsimulation. Number of teeth (time-varying) was the exposure, and baseline removable dental prostheses use was the modifier. RESULTS: Among older adults without removable dental prostheses, those with 20-32 teeth lived significantly more years without limitations than those with no teeth: 5.3 (95% CI 2.4 to 8.6), 4.2 (95% CI 1.9 to 6.5) and 2.6 (95% CI 1.3 to 4.0) additional years without ADL limitations, and 3.7 (95% CI 0.4 to 6.8), 2.5 (95% CI 0.3 to 4.3) and 1.3 (95% CI 0.2 to 2.2) additional years without physical function limitations, at ages 60, 70 and 80, respectively. Stratified analysis among non-prosthesis users detected the largest differences among males and participants with primary or less education. Among prosthesis users with secondary or higher education, those with 20-32 teeth had longer ADL limitation-free life expectancy, while those with 10-19 teeth had longer physical function limitation-free expectancy. CONCLUSIONS: Retaining more teeth may be associated with more years of independent living, without ADLs or physical function limitations. Removable dental prostheses were linked with health expectancy across sexes, highlighting the importance of both tooth retention and prosthetic rehabilitation in promoting healthy ageing.