title: What are we reading? An analysis of the orthodontic literature 1999 to 2008.
abstract: BACKGROUND
  The purpose of this study was to assess differences between articles published in the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO), the Angle Orthodontist (AO), the European Journal of Orthodontics (EJO), and the Journal of Orthodontics (JO) from 1999 to 2008.
  
  
  METHODS
  All journals were hand-searched and 4301 eligible articles were identified. A random sample of 425 articles was obtained to provide 80% power to detect a 100% increase in the number of randomized controlled trials (RCTs) at the 5% level of significance. Each article was classified according to predetermined criteria. Variations between journals were assessed using the χ(2) test or odds ratio (OR) and 95% confidence intervals (95% CI).
  
  
  RESULTS
  The AJO-DO published 45.6% of the articles in the final sample, 27.7% were from the AO, 17.4% were from the EJO, and 9.2% were from the JO. Statistically significant differences were found between the type (P <0.001), subject (P <0.001), setting (P <0.03), and method (P <0.001) of articles published in the 4 journals. The increase in the proportion of RCTs published between 1999 and 2003 and 2004 to 2008 was not statistically significant (OR 0.64; 95% CI, 0.29, 1.43).
  
  
  CONCLUSIONS
  Statistically significant differences were found in the publication profiles of the 4 orthodontic journals examined, but the increase in RCTs was lower than anticipated.
authors.affiliation: Liverpool University Dental Hospital, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Gibson
authors.forename: Jayne
authors.initials: J
authors.lastname: Harrison
mesh_terms: D015706:Bibliometrics; D018849:Controlled Clinical Trials as Topic; D003764:Dental Materials; D003792:Dental Records; D018865:Dental Research / Q000145:classification / Q000706:statistics & numerical data; D004497:Education, Dental; D006801:Humans; D015588:Observer Variation; D009970:Orthodontics / Q000193:education / Q000706:statistics & numerical data; D010506:Periodicals as Topic; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012196:Review Literature as Topic
chemical_list: D003764:Dental Materials