Early treatment of skeletal open-bite malocclusion.
METHODS
Studies were identified by searching the Cochrane Controlled Clinical Trials Register and Medline.


METHODS
Randomised clinical trials (RCT), prospective and retrospective studies that had concurrent untreated as well as normal controls, and clinical trials that compared at least two treatment strategies but did not have any untreated or normal control group were included. The following were excluded: case series; descriptive studies; case reports; studies concerning treatment in the permanent dentition/ adult patients, surgically assisted treatment, treatment combined with extractions, treatment with full-fixed appliances; and discussion or debate articles.


METHODS
Year of publication, study design, materials, dropouts, measurements, treatment time, success rate, decrease of open bite and divergence, side effects, costs, and authors' conclusions were recorded. Two independent reviewers assessed the articles independently and a quality evaluation and qualitative summary were performed.


RESULTS
A total of 1049 articles were identified of which seven were included in the review. No RCT of early treatment of anterior open bite have been performed. Two controlled clinical trials of early anterior open bite were identified, and these both indicated the effectiveness of treatment in the mixed dentition with headgear or functional appliances (or both). Most of the studies had serious problems with lack of power because of small sample size, bias and confounding variables; lack of method-error analysis or blinding in measurements; and deficient or lack of statistical methods.


CONCLUSIONS
The quality of the studies was insufficient to allow any evidence-based conclusions to be drawn. RCT of sufficient sample size are still needed to determine which treatment is the most effective for early correction of skeletal open bite. Future studies should also include the assessment of long-term stability as well as an analysis of the cost and side-effects of the interventions.
Ren
Yijin
Y
Department of Orthodontics, University Medical Centre Groningen, Groningen, The Netherlands.