title: Outcome assessment of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system.
abstract: BACKGROUND
  This treatment-outcome assessment objectively compares Invisalign (Align Technology, Santa Clara, Calif) treatment with braces.
  
  
  METHODS
  This study, a retrospective cohort analysis, was conducted in New York, NY, in 2004. Records from 2 groups of 48 patients (Invisalign and braces groups) were evaluated by using methods from the American Board of Orthodontics Phase III examination. The discrepancy index was used to analyze pretreatment records to control for initial severity of malocclusion. The objective grading system (OGS) was used to systematically grade posttreatment records. Statistical analyses evaluated treatment outcome, duration, and strengths and weaknesses of Invisalign compared with braces.
  
  
  RESULTS
  The Invisalign group lost 13 OGS points more than the braces group on average, and the OGS passing rate for Invisalign was 27% lower than that for braces. Invisalign scores were consistently lower than braces scores for buccolingual inclination, occlusal contacts, occlusal relationships, and overjet. Invisalign's OGS scores were negatively correlated to initial overjet, occlusion, and buccal posterior crossibite. Invisalign patients finished 4 months sooner than those with fixed appliances on average. P < .05 was used to determine statistically significant differences.
  
  
  CONCLUSIONS
  According to the OGS, Invisalign did not treat malocclusions as well as braces in this sample. Invisalign was especially deficient in its ability to correct large anteroposterior discrepancies and occlusal contacts. The strengths of Invisalign were its ability to close spaces and correct anterior rotations and marginal ridge heights. This study might help clinicians to determine which patients are best suited for Invisalign treatment.
authors.affiliation: Department of Orthodontics, Montefiore Medical Center/Albert Einstein College of Medicine, New York, NY 10028, USA. gdjeu@post.harvard.edu
authors.forename: Garret
authors.initials: G
authors.lastname: Djeu
authors.forename: Clarence
authors.initials: C
authors.lastname: Shelton
authors.forename: Anthony
authors.initials: A
authors.lastname: Maganzini
mesh_terms: D000328:Adult; D000367:Age Factors; D016009:Chi-Square Distribution; D015331:Cohort Studies; D006801:Humans; D008310:Malocclusion / Q000628:therapy; D016382:Orthodontic Appliance Design; D009968:Orthodontic Appliances, Removable / Q000706:statistics & numerical data*; D009971:Orthodontics, Corrective / Q000295:instrumentation / Q000379:methods*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D012189:Retrospective Studies; D012953:Societies, Dental; D018709:Statistics, Nonparametric