Effect of Tooth Loss on Cognitive Function among Older Adults in Singapore

Evidence suggests a longitudinal association between tooth loss and cognitive function. However, the temporality of this association is not well understood. We investigated the effect of several emulated tooth loss prevention scenarios on cognitive function. We used data from 3 waves (baseline: 2009, second wave: 2011–2012, and third wave: 2015) of the Panel on Health and Ageing of Singaporean Elderly (PHASE). PHASE targeted older adults, aged ≥60 y, in Singapore. Number of teeth was used as a time-varying exposure (baseline, second wave). Cognitive function (Short Portable Mental Status Questionnaire score) in the third wave was assessed as the outcome. Multiple time-invariant (baseline) and time-varying (baseline and second wave) covariates were included. The “longitudinal modified treatment policy approach” combined with targeted minimum loss–based estimation was used to define and estimate additive effects of emulated tooth loss prevention scenarios. Emulated scenarios were the following: what if edentate people retained 1 to 4 teeth (scenario 1), what if those with