title: Canine retraction rate with self-ligating brackets vs conventional edgewise brackets.
abstract: OBJECTIVE
  To compare the rates of retraction down an archwire of maxillary canine teeth when bracketed with a self-ligating bracket was used on one side and a conventional bracket on the other.
  
  
  METHODS
  In 43 patients requiring maxillary premolar extraction, a self-ligating bracket (Damon3, SmartClip) was used on the maxillary canine on one side and a conventional bracket (Victory Series) on the other. The teeth were retracted down a 0.018-inch stainless steel archwire, using a medium Sentalloy retraction spring (150 g). The rates of retraction were analyzed using a paired t-test.
  
  
  RESULTS
  The mean movement per 28 days for the conventional bracket was 1.17 mm. For the Damon bracket it was 0.9 mm and for the SmartClip bracket it was 1.10 mm. The differences between the conventional and self-ligating brackets were statistically significant: paired t-test, SmartClip, P < .0043; Damon3, P < .0001).
  
  
  CONCLUSIONS
  The retraction rate is faster with the conventional bracket, probably because of the narrower bracket width of the self-ligating brackets.
authors.affiliation: Department of Orthodontics, University of North Carolina School of Dentistry, Chapel Hill, NC, USA. hbcteam@aol.com
authors.forename: S Jack
authors.initials: SJ
authors.lastname: Burrow
mesh_terms: D003481:Cuspid / Q000503:physiopathology*; D017276:Friction; D006801:Humans; D008310:Malocclusion / Q000628:therapy; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D014081:Tooth Extraction; D014087:Tooth Movement Techniques / Q000295:instrumentation* / Q000379:methods