Worldwide prevalence of malocclusion in the different stages of dentition: A systematic review and meta-analysis.

The aim of this review is to quantify the prevalence and type of malocclusion among children and adolescents during the different stages of dentition worldwide.Recent studies (from 2009 to 2019), published in Medline, Web of Science and Embase and orthodontic text-books have been comprehensively reviewed herein. The methodological quality of the included studies was assessed using STROBE criteria.After screening 450 records and analysing 284 relevant full-text publications, 77 studies were included in this review. A good degree of evidence was obtained due to the medium-high methodological quality level of included studies. The worldwide prevalence of malocclusion was 56% (95% CI: 11-99), without differences in gender. The highest prevalence was in Africa (81%) and Europe (72%), followed by America (53%) and Asia (48%). The malocclusion prevalence score did not change from primary to permanent dentition with a common score of 54%. Malocclusion traits such as Angle's classes, overjet, overbite, and asymmetrical midline shift essentially did not change their prevalence during different dentitions. Conversely, traits such as cross-bite and diastema reduced their prevalence during permanent dentition, while scissor-bite and dental crowding increased their scores.The worldwide high prevalence of malocclusion and its early onset during childhood should induce policymakers as well as paediatric physicians and dentists to devise policies and adopt clinical strategies for preventing malocclusion since younger children's ages.