Secular trends in severe periodontitis incidence, prevalence and disability-adjusted life years in five Asian countries: A comparative study from 1990 to 2017.

AIMS: To investigate secular trends in severe periodontitis incidence, prevalence and disability-adjusted life year (DALY) rates in China, India, Japan, South Korea and Thailand from 1990 to 2017. MATERIALS AND METHODS: Data were obtained from the "Global Burden of Disease Study" 2017. The annual percentage change and average annual percentage change were calculated using Joinpoint regression analysis. The independent age, period and cohort effects were estimated by age-period-cohort analysis. RESULTS: From 1990 to 2017, the overall age-standardized incidence, prevalence and DALY rates increased in China, Japan and India, while decreasing in South Korea and Thailand. The highest incidence, prevalence and DALY rates were in India. By APC analysis, the age effect presented increase in 20-59 years in China, Japan and South Korea, 20-54 years in India and 20-64 years in Thailand; the period effect showed progressive increases in five countries, with the most significant increase shown in China; the cohort effect showed monotonic decreases with birth cohort in five countries. CONCLUSIONS: Severe periodontitis poses a serious burden in Asian countries, especially China and India. We suggest raising people's awareness of periodontal health and providing professional interventions in these countries, especially for high-risk groups, such as younger people aged </=65 years.