Epidemiological and sociodemographic transitions of severe periodontitis incidence, prevalence, and disability‐adjusted life years for 21 world regions and globally from 1990 to 2019: An age‐period‐cohort analysis

Severe periodontitis is one of the most prevalent diseases and a global public health problem due to its high incidence and prevalence. However, there are few studies on the burden of periodontitis in different regions of the world.We extracted data on the incidence, prevalence, and disability-adjusted life years (DALYs) from the Global Burden of Disease study as severe periodontitis burden measures. We also explored the global burden of severe periodontitis according to 21 world regions and Socio-Demographic Index (SDI) quintiles. The joinpoint model was used to analyze temporal trends of major regions from 1990 to 2019, and the age-period-cohort model was used to estimate age, period, and cohort trends in severe periodontitis.Globally, the age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR), and disability-adjusted life years (DALYs) rate increased from 1990 to 2019 (percentage change: 5.77%, 7.78%, and 8.01%, respectively), with average annual percent changes of 0.2%, 0.3%, and 0.3%, respectively. The region with the highest DALY rate was western sub-Saharan Africa with a value of 142.5 (95% uncertainty interval: 56.3, 303.7) per 100,000 in 2019. For the ASIR, ASPR, and DALY, the age effect of severe periodontitis showed an increase followed by a decrease, the period effect showed an upward trend, the cohort effect showed an overall decreasing trend, and the cohort relative risk for incidence for some SDI quintiles showed a slight increase in recent years.Oral health varies significantly across regions, and it is essential to address inequalities in oral health between countries. Effective measures to prevent severe periodontitis risk factors should also be taken in regions with low SDI.