Time Until Tooth Loss Among Pre-Elderly Southern Thais under Universal Coverage: A Retrospective Cohort Study

Abstract

Objective: This study used dental data to determine the time until tooth loss and its associated factors among pre-elderly individuals aged 45–59 in Southern Thailand.
Material and Methods: A retrospective cohort study was conducted using dental data from 2019 to 2023. The study included individuals under the Universal Health Coverage Scheme who received dental examinations and follow-up care. Tooth loss was defined as permanent tooth extraction (excluding impacted third molars). Data were censored if no extraction occurred by the end of the study or if participants were lost to follow-up. Cox proportional hazards models and Kaplan-Meier analyses were applied with statistical significance at p-value<0.05. Time-varying covariates were also examined.
Results: A total of 4,177 participants were included; 1,582 (37.9%) experienced tooth loss. The overall median time until tooth loss was 40.0 months (95% confidence interval [CI]: 37.9–42.3). Individuals with fewer than 20 teeth, ≥3 decayed teeth, no dental scaling, and aged 55–59 had a shorter median time until tooth loss. Multivariable analysis showed that lack of dental scaling (Hazard rate [HR] 1.53; 95% CI: 1.29–1.81) and ≥3 decayed teeth (HR 1.30; 95% CI: 1.14–1.49) were associated with earlier tooth loss.
Conclusion: Tooth loss among pre-elderly Thais occurred earlier in those with untreated caries and without dental scaling. These findings highlight the critical importance of timely caries treatment and regular scaling in preserving teeth for long-term function.