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.

2 × 4 appliance in the mixed dentition stage: a scoping review of the evidence.

A great emphasis is currently given to the early correction of malocclusions to prevent further complications if left untreated. Interceptive orthodontics not only simplifies but also eliminates the need for later procedures. The 2 × 4 appliance is an orthodontic treatment modality applied during the mixed dentition period, particularly for malpositioned permanent upper incisors. This scoping review was aimed to examine the breadth and depth of the published literature on this clinical topic, as well as knowledge gaps, about this fixed appliance during mixed dentition, for the correction of incipient anterior malocclusions (incisor crowdings, midline diastemas, or crossbites). PubMed, Cochrane Library, Google Scholar, Dentistry & Oral Sciences Source, and two grey literature databases were explored; under a structured PICO question (Patient, Intervention, Comparison, Outcome) and eligibility criteria, for relevant clinical trials, observational studies, and case reports/series (in English or Spanish), using different searching terms. Titles and abstracts were screened. Full-text articles were critically reviewed for bias risk and a data charting table was constructed. 161 references were identified, after which 115 titles remained after removing duplicates. After the abstract screening, 18 potential full-text articles were reviewed. Finally, 16 studies were included, according to the performed critical appraisal. The 2 × 4 appliance is suitable for mixed dentition patients with mild or severe malocclusions, particularly when removable appliance usage is a critical problem.