Secular Trends in the Incidence, Prevalence, and Disability-Adjusted Life Years of Caries in Permanent Teeth in Six Asian Countries: 1990 to 2021.

INTRODUCTION AND AIMS: Untreated dental caries in permanent teeth is a significant public health problem, particularly in Asia. This study compared the long-term trends in the incidence, prevalence, and disability-adjusted life year (DALY) rates of untreated dental caries in permanent teeth between China, India, Japan, South Korea, Thailand, and Singapore from 1990 to 2021. This selection provides a comprehensive representation of economic, healthcare, and demographic diversity in Asia, making our findings widely applicable.

METHODS

Data were obtained from the Global Burden of Disease Study 2021. Changes in both the annual percentage and average annual percentage were calculated using joinpoint regression analysis. Independent age, period, and cohort effects were estimated by age-period-cohort analysis.

RESULTS

From 1990 to 2021, the overall age-standardized incidence rate showed an increasing trend in China, India, and Thailand and a decreasing trend in Japan, Korea, and Singapore. The standardized prevalence and DALY rates decreased among countries, with Korea having the highest prevalence rate and India and Thailand having the highest prevalence and DALY rates. On age-period-cohort analysis, (1) the 20 to 24-year age group carried the highest caries risk, which declined with increasing age (age effect); (2) an overall decreasing or flat trend was observed (period effect); and (3) Japan, Singapore, and South Korea showed increasing incidence, prevalence, and DALY rates, whereas China, India, and Thailand exhibited decreasing prevalence and DALY rates (cohort effect).

CONCLUSION

This study revealed notable regional variations in the burden of untreated dental caries in permanent teeth across Asia from 1990 to 2021. These findings provide valuable insights for policymakers and healthcare professionals to develop targeted and evidence-based oral health strategies in the region.

CLINICAL RELEVANCE: These findings underscore the need to develop targeted oral health solutions in Asia.