title: Comparison of maxillary arch dimensional changes with passive and active self-ligation and conventional brackets in the permanent dentition: a multicenter, randomized controlled trial.
abstract: BACKGROUND
  The purpose of this study was to compare maxillary arch dimensional and inclination changes during alignment with conventional brackets and self-ligation.
  
  
  METHODS
  Ninety-six patients, ages 16 years and above, were included in this multicenter, 3-group parallel randomized trial. The main outcome measures were changes in maxillary intercanine, interpremolar, and intermolar dimensions, and molar and incisor inclination changes. The patients were randomly allocated in permuted blocks of 12 subjects into 3 equal groups with the allocations concealed in opaque sealed envelopes. Each participant underwent alignment with a standard Damon Q (Ormco, Orange, Calif) wire sequence for a minimum of 34 weeks. Blinding of clinicians and patients was not possible. Data were analyzed on a per-protocol basis, since losses to follow-up were minimal.
  
  
  RESULTS
  Complete data were obtained from 87 subjects. Bracket type had no significant effect on any of the transverse dimensional changes. No difference in molar inclination was found between passive self-ligation and conventional brackets (0.67°; 95% CI, -2.24, 3.58; P = 0.65) or active self-ligation (0.91°; 95% CI, -1.95, 3.78; P = 0.53). Similarly, incisor inclination changes with the Damon Q could not be differentiated from those developing with either conventional system (0.44°; 95% CI, -1.93, 2.8; P = 0.71) or In-Ovation C (-0.22°; 95% CI, -2.58, 2.14; P = 0.85). No harms were encountered.
  
  
  CONCLUSIONS
  No difference in the arch dimensional or inclination changes during alignment can be expected between conventional brackets and either active or passive self-ligation.
authors.affiliation: Queen Mary University of London, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, London, United Kingdom. padhraig.fleming@gmail.com
authors.forename: Padhraig S
authors.initials: PS
authors.lastname: Fleming
authors.forename: Robert T
authors.initials: RT
authors.lastname: Lee
authors.forename: Valeria
authors.initials: V
authors.lastname: Marinho
authors.forename: Ama
authors.initials: A
authors.lastname: Johal
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000473:pathology; D002508:Cephalometry / Q000379:methods*; D003481:Cuspid / Q000473:pathology; D003722:Dental Alloys / Q000737:chemistry; D003724:Dental Arch / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy; D008313:Malocclusion, Angle Class III / Q000628:therapy; D008437:Maxilla / Q000473:pathology*; D008963:Molar / Q000473:pathology; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets / Q000145:classification*; D009969:Orthodontic Wires; D012984:Software; D013193:Stainless Steel / Q000737:chemistry; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003722:Dental Alloys; D013193:Stainless Steel