A systematic review of clinical trials of aligning archwires.

OBJECTIVES This review aimed to identify the evidence for the efficacy of archwires used in the alignment stage of orthodontic treatment by undertaking a systematic review of the literature. DATA SOURCES MEDLINE, the Cochrane Central Register of Controlled trials (CENTRAL), EMBASE, and the meta Register of Controlled Trials were searched up to July 2008. Reference lists of identified articles and relevant review articles were checked for further possible studies. REVIEW METHODS Controlled clinical trials and randomised clinical trials that compared aligning archwires and reported objective measures of alignment were selected for inclusion. Validity and quality assessment were undertaken to identify studies with a low risk of bias. Details of the study methodology and the reported results were then abstracted. RESULTS 100 studies were identified by the searches and 7 of these were identified as meeting the selection criteria. Four studies were deemed, after quality assessment, to have a low risk of bias and data was extracted from these. No two studies shared a common methodology or common reporting of outcome. Meta-analysis was therefore not possible. CONCLUSIONS There is insufficient data in these studies to make clear recommendations regarding the most effective archwire for alignment. Recommendations on future study design have been made.