Extraction or non-extraction treatment for Class II division 2 malocclusion?

Data sourcesThe following databases were searched: Cochrane Oral Health Trial Register, Cochrane central register for controlled trials, Medline Ovid and Embase Ovid. The following were searched for ongoing trials: US National Institutes of Health Trials Register and World Health Organization International Clinical Trials Registry Platform. No language, publication year or publication status restrictions were imposed.Study selectionRandomised controlled trials (RCTs) and controlled clinical trials (CCTs) of orthodontic treatment to correct deep bite and retroclined upper front teeth were included. Two independent reviewers scanned and reviewed all papers and abstracts to be included. When necessary, primary authors were contacted, and additional or missing information was obtained. Trials which recruited participants 16 years or less without surgical intervention to correct their class II malocclusion were to be included. Trials that included participants with cleft lip/palate or any other craniofacial syndrome were excluded.Data extraction and synthesisIf data were to be selected, all data would have been complied into a customised data collection form. The following were to be included in the analysis; year of publication, country of origin, setting and source of study funding and details on the type of interventions including appliance type. Additionally, details of the participants including demographic characteristics, criteria for inclusion and exclusion and sample size by study group were to be taken into account. Details of the outcomes reported, including method of assessment, time intervals, details of withdrawals by study group, details of outcomes, including measures and timepoints were also supposed to be compiled for completeness. The risk of bias was planned to be reviewed. Measurements of treatment effect including risk ratios and numbers needed to treat would have been included. A 95% confidence interval and assessment of heterogeneity were to be explored. Data synthesis was planned to follow the Cochrane statistical guidelines using Review Manager Software.ResultsOne thousand three hundred and forty-four records were identified through database searching and one extra article was identified through other sources. Eight hundred and fifty-seven records were isolated after duplicates were removed. All records were rejected. No articles were selected for inclusion. No RCTs or CCTs were found assessing orthodontic treatment without the removal of permanent teeth versus treatment with extraction of permanent teeth versus no treatment at all. Consequently, it is impossible to derive any evidence-based support for clinicians for the treatment of class II division 2 malocclusion in children.ConclusionsThere is no evidence from clinical trials to recommend or discourage any type of orthodontic treatment to correct Class II division 2 malocclusion in children. This situation seems unlikely to change as trials to evaluate the best management of Class II division 2 malocclusion are challenging to design and conduct due to low prevalence, difficulties with recruitment and ethical issues with randomisation.