Global and regional trends in prevalence of untreated caries in permanent teeth: Age-period-cohort analysis from 1990 to 2019 and projections until 2049

This study aims to update the relevant epidemiological information of untreated caries in permanent teeth. Data were derived from the Global Burden of Disease (GBD) study 2019. We described temporal trends in age-standardized prevalence rate (ASPR) of untreated caries in permanent teeth by gender and region from 1990 to 2019. Age-period-cohort (APC) model was utilized to analyze age, period and cohort effects on prevalence, and we used the Bayesian age-period-cohort (BAPC) model to make projections of prevalence between 2020 and 2049. The global ASPR of untreated caries in permanent teeth presented a decreasing trend from 1990 to 2019 (26593.58/105 vs. 25625.53/105), with females exceeding males annually. Negative correlation was observed between ASPR and Socio-demographic Index (SDI) levels. APC analyses showed that net drift was -0.16 % globally and generally below 0 across all SDI regions. The overall global peak in prevalence occurred in the 20–24 years group (36319.99/105), and there was a decrease trend in the overall global period rate ratio (RR). Compared to younger birth cohorts, prior birth cohorts had higher prevalence risks globally and across all SDI regions. Significant upward trends was predicted in the global ASPR of untreated caries in permanent teeth for both genders from 2020 to 2049. Age-period-cohort effects exerted a significant impact on the prevalence of untreated caries in permanent teeth during the study period. The ASPR of untreated caries in permanent teeth may increase in the next 30 years by projections. And the disease burden of untreated caries in permanent teeth may be affected by population ageing. It is essential to implement targeted prevention and control policies to disadvantaged groups and attempt to reduce caries inequalities.