In the last decade, there has been a significant increase in the number of self-ligated bracket systems available to orthodontists. Currently, 1 market leader is the Damon system (Ormco, Glendora, Calif), which advocates a treatment philosophy based on the use of a passive self-ligated bracket design and superelastic nickel-titanium archwires. According to proponents of this system, the low-force and low-friction environment provided by the Damon appliance offers considerable advantages over those with conventional ligation. These include greater patient comfort during treatment, fewer visits to the orthodontist, shorter overall treatment times, less need for extractions, and better outcomes in terms of both occlusal and facial esthetics.

To date, these claims have been based on theoretical arguments, isolated case reports, case series, and retrospective comparisons. Although attempts have been made to achieve equivalence between samples compared retrospectively, some studies have suffered from poor design, inadequate reporting, and significant bias. In an attempt to improve the evidence base relating to the Damon system, several prospective randomized clinical trials have been instigated. Some of these have compared pain and discomfort caused by several Damon bracket designs and conventional ligation during the initial alignment phase of treatment and, collectively, have shown that the Damon system is not associated with any significant reductions in pain and discomfort compared with conventional appliances. They have also reported on the rate of initial tooth alignment, where there is weak evidence that Damon2 brackets can resolve mild crowding more rapidly than conventional appliances when this treatment is carried out on a nonextraction basis. However, for more severe crowding treated with the Damon3 bracket and first premolar extractions, this is not the case. In addition, the Damon MX passive self-ligated bracket cannot resolve maxillary anterior crowding any more effectively than an In-Ovation R with active self-ligation. Collectively, these studies have also demonstrated that the Damon appliance does not align teeth in a qualitatively different manner from conventional or active self-ligated appliances; incisor proclination and canine expansion occur just as readily with the Damon system as they do with conventional ligated preadjusted brackets. Although the literature relating to the clinical use of self-ligated bracket systems is relatively new, currently little objective evidence suggests that they offer significant advantages with regard to treatment efficiency when compared with conventional appliances.

However, the period of initial alignment contributes toward only 1 part of the overall treatment time, which in total depends on many other factors. These can be patient-based, such as age, severity of the underlying malocclusion, and compliance, or treatment-based, including factors such as the decision to extract teeth, the need for overbite reduction, and space closure. Therefore, for any investigation of overall treatment effectiveness, it is important to evaluate this over the entire duration, from appliance placement to removal on completion. Moreover, for a sample with pretreatment equivalence, the duration of treatment is relevant only when evaluated in relation to outcome. Treatment outcome can be assessed in many ways, but one of the most recognized is the peer assessment rating (PAR), which provides a validated numeric score based on several occlusal features before and after treatment. The difference in these scores gives an indication of improvement in treatment and whether the occlusal aims were achieved.

The aim of this randomized clinical trial was to compare the efficiency of treatment by using Damon3 self-ligated and conventional bracket systems in terms of overall treatment time, number of visits, and occlusal outcome, as measured by the PAR index.