Rapid maxillary expansion and its consequences on the nasal and oropharyngeal anatomy and breathing function of children and adolescents: An umbrella review

Objective: To identify, qualify, and summarize the evidence from different systematic reviews about the outcomes of Rapid Maxillary Expansion (RME) on upper airway dimensions and breathing function in young patients.Methods: A literature search (from 2000 to December 2022) was conducted through PubMed (MEDLINE), the Cochrane Library, EMBASE, and Dentistry & Oral Science Source. The authors conducted the following umbrella review phases: research question, study selection criteria (systematic reviews involving randomized clinical trials and longitudinal observational designs), data extraction, and critical appraisal (bias risk assessment) of selected articles through the ROBIS tool.Results: The initial search yielded 65 potential references. After screening titles and summaries, and the elimination of duplicated publications, 15 articles were eligible for the evaluation of the full-text document. Finally, 11 systematic reviews (5 combined with meta-analysis) were selected, reporting 132 single studies; 38 of them were unrepeatable. Risk-of-bias assessment showed an average global moderate/high quality among the included studies. There was high heterogeneity between the systematic reviews' (and meta-analyses') methodologies used.Conclusions: The present umbrella review concludes that significant and stable increases in the nasal and oropharyngeal space volumes and a decrease in airway resistance of growing children and adolescents, occur immediately after RME and at 3, 6-and 12-months follow-up.