title: How long does treatment with fixed orthodontic appliances last? A systematic review.
abstract: BACKGROUND
  There is little agreement on the expected duration of a course of orthodontic treatment; however, a consensus appears to have emerged that fixed appliance treatment is overly lengthy. This has spawned numerous novel approaches directed at reducing the duration of treatment, occasionally with an acceptance that occlusal outcomes may be compromised. The aim of this study was to determine the mean duration and the number of visits required for comprehensive orthodontic treatment involving fixed appliances.
  
  
  METHODS
  Multiple electronic databases were searched with no language restrictions, authors were contacted as required, and reference lists of potentially relevant studies were screened. Randomized controlled trials and nonrandomized prospective studies concerning fixed appliance treatment with treatment duration as an outcome measure were included. Data extraction and quality assessment were performed independently and in duplicate.
  
  
  RESULTS
  Twenty-five studies were included after screening: 20 randomized controlled trials and 5 controlled clinical trials. Twenty-two studies were eligible for meta-analysis after quality assessment. The mean treatment duration derived from the 22 included studies involving 1089 participants was 19.9 months (95% confidence interval, 19.58, 20.22 months). Sensitivity analyses were carried out including 3 additional studies, resulting in average duration of treatment of 20.02 months (95% confidence interval, 19.71, 20.32 months) based on data from 1211 participants. The mean number of required visits derived from 5 studies was 17.81 (95% confidence interval, 15.47, 20.15 visits).
  
  
  CONCLUSIONS
  Based on prospective studies carried out in university settings, comprehensive orthodontic treatment on average requires less than 2 years to complete.
authors.affiliation: Senior registrar, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, United Kingdom.
authors.forename: Aliki
authors.initials: A
authors.lastname: Tsichlaki
authors.affiliation: Registrar, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, United Kingdom.
authors.forename: Siew Yee
authors.initials: SY
authors.lastname: Chin
authors.affiliation: Assistant professor, Department of Orthodontics, Dental School, Medical Faculty, University of Bern, Bern, Switzerland; private practice, Corfu, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Pandis
authors.affiliation: Senior clinical lecturer and consultant, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, United Kingdom. Electronic address: padhraig.fleming@gmail.com.
authors.forename: Padhraig S
authors.initials: PS
authors.lastname: Fleming
mesh_terms: D006801:Humans; D065228:Non-Randomized Controlled Trials as Topic; D009967:Orthodontic Appliances; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation*