Impact of malocclusion on bullying in school children and adolescents: A systematic review and meta-analysis

Aim: To answer the following research question: "School children and adolescents with malocclusion are more likely to be victims of bullying than those without malocclusion? ".Material and methods: An electronic search was conducted in ten databases, including the grey literature. Observational studies that evaluated the association between malocclusion traits and bullying in children and adolescents were included without restrictions on year or language of publication. Two reviewers selected the studies, performed the data extraction, assessed the individual risk of bias of the eligible studies with the appropriate JBI critical appraisal tools, and analyzed confounding factors, selection bias, and information bias in individual studies, according to COSMOS-E guidance. Fixed-effect meta-analysis with Odds Ratio (OR) as mea-sure effect and 95% confidence was performed for data synthesis. The GRADE approach was used to assess the certainty of the evidence.Results: The electronic search, studies suggested by experts, and search in references list (eligible studies and systematic review) found 3,336 records, of which only twenty studies were included in the qualitative analysis. Seven studies were classified as low risk of bias, nine studies as moderate risk, and four studies as high risk. Based on five studies, the meta-analysis did not find a significant association between malocclusion and bullying (OR = 1.20, 95 % CI: 0.72-2.00; I2 = 66 %).Conclusion: Based on very low certainty of the evidence, the establishment of a link between malocclusion traits and bullying is not possible.