The Relationship Between Malocclusion and Periodontal Health in Children and Adolescents: A Systematic Review and Meta-Analysis

<b>Background/Objectives:</b> Evidence regarding the effect of malocclusion on periodontal health is contradictory. This systematic review with meta-analysis seeks to summarize the available scientific evidence on the relationship between malocclusion and periodontal health in children and adolescents. <b>Methods</b>: A review of four electronic databases (PubMed, Scopus, Embase, and Web of Science) was performed. Observational studies were included if they investigated the link between malocclusion and periodontal health in children and adolescents. The quality of the studies included in the review was determined using the Newcastle-Ottawa Scale (NOS). A meta-analysis was conducted on binary outcomes using random-effect models. The Grading Recommendations Assessment, Development and Evaluation (GRADE) tool was used to determine the certainty of the evidence for each outcome. <b>Results</b>: The initial search yielded 774 potential articles. Nineteen articles were selected for the final qualitative analysis, and four of these were included in the meta-analysis. Certain malocclusion traits appear to be associated with less favorable periodontal health indicators in children and adolescents. Quantitative synthesis restricted to studies using the Gingival Bleeding Index (GBI) suggests that malpositioned teeth, such as crowding or lack of spacing, and Class II or Class III molar relationships may be associated with a higher odds of gingivitis in individuals under 18 years of age. The overall quality of evidence of the studies was very low, according to the GRADE criteria. <b>Conclusions</b>: Observational cross-sectional evidence of very low certainty suggests an association between certain malocclusions (crowding, lack of spacing, Class II or Class III molar relationships) and increased odds of gingivitis in children and adolescents. Evidence regarding dental plaque accumulation is inconsistent and limited by substantial heterogeneity across studies. Causality cannot be inferred, and further high-quality longitudinal studies are required.