Long-term trends in the burden of edentulism in China over three decades: A Joinpoint regression and age-period-cohort analysis based on the global burden of disease study 2019.

Background: To investigate secular trends in edentulism incidence, prevalence, and years lived with disability (YLDs) rates in Chinese men and women from 1990 to 2019. Methods: Data were obtained from the Global Burden of Disease Study 2019. The annual percentage change and average annual percentage change were calculated using Joinpoint regression analysis. The age-period-cohort (APC) analysis estimated the independent age, period, and cohort effects. Results: From 1990 to 2019, the crude incidence, prevalence, and YLDs of edentulism in the Chinese population increased year by year, while the age-standardized incidence, prevalence, and YLDs decreased, and the latter was higher in women than in men. The APC analysis showed that the age effect increased in men and women from age 20 to 74 and decreased thereafter. The risk of tooth loss increased with age. However, the relationship was not linear. The temporal effect showed a gradual increase; the risk of missing teeth gradually increased with the changing modern living environment. The cohort effect showed a single decreasing trend, with the early birth cohort having a higher risk of tooth loss than the later birth cohort population. The age, period, and cohort effects were consistent for both sexes. Conclusion: Although the standardized incidence, prevalence, and YLD rate and cohort effect of dentition loss in China are declining, they are still causing a severe burden to China due to the continued aging of the population and the rising period effect. Despite the decreasing trends of the standardized incidence and prevalence of dentition loss and the rate of YLDs, China should develop more effective oral disease prevention and control strategies to reduce the increasing burden of edentulism in the older adult, especially in older women.

Comparison of vacuum-formed and Hawley retainers: a systematic review.

INTRODUCTION: Hawley retainers (HRs) and vacuum-formed retainers (VFRs) are the 2 most commonly used retainers in orthodontics. However, the basis for selection of an appropriate retainer is still a matter of debate among orthodontists. In this systematic review, we evaluated the differences between VFRs and HRs. METHODS: Electronic databases (PubMed, EMBASE, Cochrane Library, ISI Web of Science, LILACS, and Pro-Quest) were searched with no language restriction. The relevant orthodontic journals and reference lists were checked for all eligible studies. Two article reviewers independently screened the retrieved studies, extracted the data, and evaluated the quality of the primary studies. RESULTS: A total of 89 articles were retrieved in the initial search. However, only 7 articles met the inclusion criteria. Some evidence suggested that no difference exists to distinguish between the HRs and VFRs with respect to changes in intercanine and intermolar widths after orthodontic retention. In terms of occlusal contacts, cost effectiveness, patient satisfaction, and survival time, there was insufficient evidence to support the use of VFRs over HRs. CONCLUSIONS: Additional high-quality, randomized, controlled trials concerning these retainers are necessary to determine which retainer is better for orthodontic procedures.