title: Canine retraction and anchorage loss: self-ligating versus conventional brackets in a randomized split-mouth study.
abstract: OBJECTIVE
  To evaluate the velocity of canine retraction, anchorage loss and changes on canine and first molar inclinations using self-ligating and conventional brackets.
  
  
  METHODS
  Twenty-five adults with Class I malocclusion and a treatment plan involving extractions of four first premolars were selected for this randomized split-mouth control trial. Patients had either conventional or self-ligating brackets bonded to maxillary canines randomly. Retraction was accomplished using 100-g nickel-titanium closed coil springs, which were reactivated every 4 weeks. Oblique radiographs were taken before and after canine retraction was completed, and the cephalograms were superimposed on stable structures of the maxilla. Cephalometric points were digitized twice by a blinded operator for error control, and the following landmarks were collected: canine cusp and apex horizontal changes, molar cusp and apex horizontal changes, and angulation changes in canines and molars. The blinded data, which were normally distributed, were analyzed through paired t-tests for group differences.
  
  
  RESULTS
  No differences were found between the two groups for all variables tested.
  
  
  CONCLUSIONS
  Both brackets showed the same velocity of canine retraction and loss of anteroposterior anchorage of the molars. No changes were found between brackets regarding the inclination of canines and first molars.
authors.affiliation: a  PhD student, Faculdade de Odontologia de Araraquara, Universidade Estadual Paulista, UNESP, Araraquara, SP, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: da Costa Monini
authors.forename: Luiz Gonzaga Gandini
authors.initials: LG
authors.lastname: Júnior
authors.forename: Renato Parsekian
authors.initials: RP
authors.lastname: Martins
authors.forename: Alexandre Protásio
authors.initials: AP
authors.lastname: Vianna
mesh_terms: D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000473:pathology; D001641:Bicuspid / Q000601:surgery; D002508:Cephalometry / Q000379:methods; D003481:Cuspid / Q000473:pathology*; D003722:Dental Alloys / Q000737:chemistry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology; D009532:Nickel / Q000737:chemistry; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D014025:Titanium / Q000737:chemistry; D019227:Tooth Apex / Q000473:pathology; D019228:Tooth Crown / Q000473:pathology; D014081:Tooth Extraction / Q000379:methods; D014087:Tooth Movement Techniques / Q000295:instrumentation*; D055815:Young Adult
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Anchorage; Canine retraction; Self-ligating brackets; Tooth movement rate