Content area
Abstract
Data sourcesMedline (Pubmed), Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Google Scholar, Web of Science, Evidence-based Medicine, Scopus, LILACS database, Ovid database, Bibliografia Brasileira de Odontolgogia, Bandolier, Atypon Link, African Journals Online, ProQuest, Conference Paper Index, German National Library of Medicine, metaRegister of Controlled Trials.Study selectionRandomised Controlled Trials (RCT) or prospective Controlled Clinical Trials (pCCT) in patients with Class II malocclusions that compared at least one removable functional appliance (RFA) with a non-intervention control. Primary outcomes were angular measurements of skeletal, dental and soft tissue changes as measured by lateral cephalographs.Data extraction and synthesisTwo reviewers independently extracted data and assessed risk of bias. A third author assessed bias across studies. Pooling of data was done if similar control groups were used and if the same angular cephalometric measurements were reported. A random-effects model was used to analyse pooled estimates and results were expressed as mean differences (MDs) and 95% confidence intervals (CI). The extent and impact of heterogeneity was assessed.ResultsData were pooled from seventeen studies (seven RCTs and ten pCCT) involving 1031 patients with a mean age of 10.6 years. Most of the RCTs were associated with high risk of bias while most of the pCCTs were without serious methodological limitations. RFA treatment in Class II malocclusions was shown to have a statistically significant short-term effect on skeletal, dental and soft tissue relationships when compared to untreated controls. There is a minimal reduction of SNA (MD=-0.26 degree/year, 95% CI=-0.44 to -0.12 degree/year), minimal increase of SNB (MD=0.62 degree/year, 95% CI=0.36 to 0.88 degree/year) and a small decrease in ANB (MD= -1.14degree/year, 95% CI=-1.52 to 0.77 degree/year). Maxillary incisors were significantly retroclined (1s-NL=-6.33 degree/year) while mandibular incisors were proclined (1i-ML=1.37 degree/year). Soft tissue cephalometric variables were significantly affected with mentolabial angle showing the biggest effect size (MD=22.6 degree/year; 95% CI = 18.31to 26.9 degree/year).ConclusionsEvidence indicates that RFAs are effective in improving Class II malocclusions in the short term. While the skeletal changes are minimal, significant dentoalveolar retroclination of maxillary incisors and proclination of mandibular incisors and soft tissue changes occurred with RFAs.