Non-surgical treatment of skeletal Class II malocclusion in children and adolescents: an umbrella review

Abstract Background Class II malocclusion is primarily caused by mandibular retrusion and has significant functional, aesthetic, and psychological implications. Although there are many non-surgical treatment options available, their actual skeletal effects are still mild, varied, and not always reported. Clear conclusions have been limited by overlapping data and variable quality, despite these interventions being the subject of numerous systematic reviews (SRs). Objectives To synthesize and critically appraise evidence from published SRs of the efficacy of orthodontic and dentofacial orthopaedic interventions for skeletal Class II malocclusion. Search Methods PubMed, Scopus, Embase and Google Scholar were systematically searched till May 2025. A manual citation search was also performed. Selection Criteria SRs involving children or adolescents with clinically and/or radiographically confirmed sagittal skeletal discrepancies, assessing non-surgical interventions against any comparator, and evaluating outcomes including skeletal changes, patient-reported measures, or operator-related measures, using qualitative, quantitative, or mixed synthesis, without restrictions on language or publication year, were included. Data Collection and Analysis Two independent reviewers selected the included reviews, initially by screening titles and abstracts, and then by reading the full texts. Methodological quality was evaluated using the AMSTAR-2, and the risk of bias was assessed using the ROBIS. Overlap of primary studies was quantified using the GROOVE tool. When second-order meta-analysis (meta-meta-analysis or MMA) was feasible, random-effects models were used; otherwise, narrative synthesis was performed. The certainty of evidence was rated using the GRADE method. Results Twenty-eight SRs were included. The most consistent skeletal improvements, particularly in ANB and SNB angles and mandibular length, were shown by removable functional appliances (RFAs), especially the Twin Block. Fixed functional appliances produced favourable but more variable effects, while headgear reduced maxillary growth but was compliance-dependent. Incremental mandibular advancement offered little advantage over single-step protocols, and no clear benefit was observed for early versus late treatment. Considerable heterogeneity and overlap across reviews limit confidence in pooled estimates. Conclusions RFAs show the most consistent direction of skeletal improvement, although the magnitude of change is modest and the certainty of evidence is predominantly low. Findings for other approaches remain inconsistent and methodologically limited. Future research must incorporate standardized protocols, age-stratified outcomes, and patient-centred measures through rigorously designed randomized controlled trials to strengthen clinical guidance. Registration PROSPERO: CRD42024565809.