Global and regional burden and inequalities of oral conditions in children, adolescents, and young adults (0-39 years), 1990 to 2021.

Previous Global Burden of Disease studies often encompassed the entire age spectrum or treated adolescents and young adults as a single cohort. This methodology has limited the opportunity for a detailed analysis and modelling of oral health within specific subgroups of the younger population. This study examines the lifecycle-specific burden, trends, and inequalities of oral disorders among children, adolescents, and young adults from 1990 to 2021, utilizing data from the Global Burden of Disease 2021. Age-standardized Years Lived with Disability (YLD) rates were calculated by sex, age subgroups, and sociodemographic index (SDI) quintiles, followed by incidence and prevalence calculations. The study utilized Joinpoint regression, decomposition analysis, slope/concentration index, and sociodemographic attribution analysis to assess the epidemiology of oral disorders. As a result, in 2021, there were 6.22 (3.40-10.57) million YLDs associated with oral disorders among children, adolescents, and young adults globally. Temporal trends indicated a post-pandemic rise in deciduous caries among children. The number of YLDs of caries in children, adolescents, and young adults has all increased despite declining age-standardized YLD rates in 1990-2021 due to population growth in lower-SDI locations. The number and age-standardized YLD rates of periodontal disease and edentulism have risen among adolescents and young adults, exacerbated by worsened epidemiology and population growth. Despite improvements in 2021 compared to 1990, inequalities in periodontal disease burdens persist, disproportionately affecting lower SDI locations. Findings of this study reveal that oral disorder epidemiological metrics among individuals aged 0-39 have generally improved for caries but worsened for periodontal diseases and edentulism. Population growth in lower-SDI locations primarily drove the global increased burdens. SDI-related inequalities disproportionately concentrated periodontal disease burdens in lower-SDI locations. Targeted healthcare resource allocation is essential for youth population to address the increased burdens and inequalities and enhance universal health coverage.