title: Duration of treatment and occlusal outcome using Damon3 self-ligated and conventional orthodontic bracket systems in extraction patients: a prospective randomized clinical trial.
abstract: BACKGROUND
  This was a prospective randomized clinical trial comparing the effect of bracket type on the duration of orthodontic treatment and the occlusal outcome as measured by the peer assessment rating (PAR).
  
  
  METHODS
  A multi-center randomized clinical trial was carried out in 2 orthodontic clinics. Sixty-two subjects (32 male, 30 female; mean age, 16.27 years) with a mean pretreatment PAR score of 39.40, mandibular irregularity from 5 to 12 mm, and prescribed extractions including mandibular first premolars were randomly allocated to treatment with either the Damon3 self-ligated or the Synthesis conventional ligated preadjusted bracket systems (both, Ormco, Glendora, Calif). An identical archwire sequence was used in both groups excluding the finishing archwires: 0.014-in, 0.014 × 0.025-in, and 0.018 × 0.025-in copper-nickel-titanium aligning archwires, followed by 0.019 × 0.025-in stainless steel working archwires. Data collected at the start of treatment and after appliance removal included dental study casts, total duration of treatment, number of visits, number of emergency visits and breakages during treatment, and number of failed appointments.
  
  
  RESULTS
  Sixty-two patients were recruited at the start of treatment, and the records of 48 patients were analyzed after appliance removal. Accounting for pretreatment and in-treatment covariates, bracket type had no effect on overall treatment duration, number of visits, or overall percentage of reduction in PAR scores. Time spent in space closure had an effect on treatment duration, and the pretreatment PAR score influenced only the reduction in PAR as a result of treatment.
  
  
  CONCLUSIONS
  Use of the Damon3 bracket does not reduce overall treatment time or total number of visits, or result in a better occlusal outcome when compared with conventional ligated brackets in the treatment of extraction patients with crowding.
authors.affiliation: Department of Orthodontics, East Kent Hospitals University Foundation NHS Trust, Canterbury, United Kingdom.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: DiBiase
authors.forename: Inas H
authors.initials: IH
authors.lastname: Nasr
authors.forename: Paul
authors.initials: P
authors.lastname: Scott
authors.forename: Martyn T
authors.initials: MT
authors.lastname: Cobourne
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001071:Appointments and Schedules; D001641:Bicuspid / Q000601:surgery; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008334:Mandible; D009819:Office Visits; D016910:Orthodontic Brackets; D009971:Orthodontics, Corrective / Q000295:instrumentation* / Q000379:methods; D018024:Peer Review, Health Care; D011446:Prospective Studies; D013997:Time Factors; D014081:Tooth Extraction; D016896:Treatment Outcome