Woon SC, Thiruvenkatachari B.
Early orthodontic treatment for Class III malocclusion: A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop 2017; 151: 28-52.Question: Is early treatment of class III malocclusions effective?
Data sources The Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, Medline and the ClinicalTrials.gov databases.Question: Is early treatment of class III malocclusions effective?
Study selection Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of children aged 7-12 years with class III malocclusion undergoing fixed or removable orthodontic treatment for early correction were included.Question: Is early treatment of class III malocclusions effective?
Data extraction and synthesis Two reviewers independently selected studies, abstracted data and assessed risk of bias. The Cochrane risk of bias tool was used for RCTs and the Downs and Black and the Newcastle-Ottawa scales for CCTs. The primary outcome was correction of reverse overjet. Mean differences (MD) with 95% confidence intervals were calculated and a random effects metaanalysis conducted.Question: Is early treatment of class III malocclusions effective?
Results Fifteen studies (nine RCTs, six CCTs) were included. Only three of the RCTs were considered to be at low risk of bias, all six CCTs were at high risk of bias.Three RCTs (141 patients) compared protraction facemask and untreated control. The results for reverse overjet (MD = 2.5 mm; 95% CI, 1.21-3.79) and ANB angle (MD = 3.90°; 95% CI, 3.54-4.25) were statistically significant favouring the facemask group. All CCTs demonstrated a statistically significant benefit in favour of the use of each appliance. However, the studies had high risk of bias.Question: Is early treatment of class III malocclusions effective?
Conclusions There is a moderate amount of evidence to show that early treatment with a facemask results in positive improvement for both skeletal and dental effects in the short term. However, there was lack of evidence on long-term benefits. There is some evidence with regard to the chincup, tandem traction bow appliance and removable mandibular retractor, but the studies had a high risk of bias. Further high-quality, long-term studies are required to evaluate the early treatment effects for Class III malocclusion patients.