title: Retrospective investigation of the effects and efficiency of self-ligating and conventional brackets.
abstract: BACKGROUND
  The purpose of this retrospective cohort study was to assess the effects and efficiency of self-ligating brackets compared with conventional brackets. A secondary purpose was to identify the pretreatment factors associated with the choice of self-ligating or conventional brackets.
  
  
  METHODS
  The subjects were treated by 2 private practitioners who used both self-ligating and conventional brackets in their practices. The self-ligating subjects were consecutively identified (treatment completed between January 2011 and April 2012), and then an age- and sex-matched control group was chosen from the same office. The outcome measures were changes in arch dimensions, changes in mandibular incisor inclinations, final peer assessment rating (PAR) scores, percentages of PAR reduction, overall treatment times, total number of visits, and number of emergency visits. All cast and cephalometric measurements were performed on digital records in a blinded manner. Two calibrated assessors measured the PAR scores.
  
  
  RESULTS
  The final sample comprised 74 patients from clinician 1 and 34 patients from clinician 2. The practitioners had significant differences for several treatment parameters; therefore, the data from the 2 clinicians were analyzed separately. For clinician 1, no significant differences were observed between the self-ligating and conventional groups, other than increased arch length in the self-ligating group. The self-ligation patients treated by clinician 2 demonstrated significant increases in transverse dimensions, lower percentages of reduction in PAR scores, shorter treatment times, fewer visits, and more wire-sliding emergencies than the conventional bracket group.
  
  
  CONCLUSIONS
  Although some significant findings were observed, the small sample and the lack of consistent findings between the 2 clinicians made it difficult to draw strong conclusions.
authors.affiliation: Private practice, Bellevue, Wash. Electronic address: meghaa@uw.edu.
authors.forename: Megha
authors.initials: M
authors.lastname: Anand
authors.affiliation: Moore-Riedel professor, Department of Orthodontics, School of Dentistry, University of Washington, Seattle, Wash.
authors.forename: David L
authors.initials: DL
authors.lastname: Turpin
authors.affiliation: Postgraduate student, Department of Orthodontics, School of Dentistry, University of Washington, Seattle, Wash.
authors.forename: Ketan S
authors.initials: KS
authors.lastname: Jumani
authors.affiliation: Research scientist, Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, Wash.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Spiekerman
authors.affiliation: Professor and chair, Department of Orthodontics, School of Dentistry, University of Washington, Seattle, Wash.
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D016910:Orthodontic Brackets; D012189:Retrospective Studies; D055815:Young Adult