Randomised controlled (RCTs) and quasi-randomised clinical trials (CCTs) that evaluated health promotion interventions in patients who underwent orthodontic treatment with fixed appliances and that measured reductions in dental plaque levels and/or gingival bleeding were eligible for inclusion. Trials of plaque removal by a professional or use of proprietary antiplaque agents were excluded.
Included studies evaluated a range of educational interventions; one study assessed an environmental change. Study duration ranged from eight weeks to 10 months. Outcome measures included plaque index, gingival index, orthodontic patient cooperation scale, oral and modified oral hygiene index and flow of gingival exudate.
The authors did not state how many reviewers performed the study selection.