title: Maxillary molar distalization with aligners in adult patients: a multicenter retrospective study.
abstract: BACKGROUND
  The aim of the present study was to test the hypothesis that bodily maxillary molar distalization was not achievable in aligner orthodontics.
  
  
  METHODS
  Forty lateral cephalograms obtained from 20 non-growing subjects (9 male, 11 female; average age 29.73 years) (group S), who underwent bilateral distalization of their maxillary dentition with Invisalign aligners (Align Technology, Inc., San José, CA, USA), were considered for the study. Skeletal class I or class II malocclusion and a bilateral end-to-end class II molar relationship were the main inclusion criteria. Cephalograms were taken at two time points: (T0) pretreatment and (T2) post-treatment. Treatment changes were evaluated between the time points using 39 variables by means of paired t test. The level of significance was set at P < 0.05. Reproducibility of measurements was assessed by the intraclass correlation coefficient (ICC).
  
  
  RESULTS
  The mean treatment time was 24.3 ± 4.2 months. At the post-treatment point, the first molar moved distally 2.25 mm without significant tipping (P = 0.27) and vertical movements (P = 0.43). The second molar distalization was 2.52 mm without significant tipping (P = 0.056) and vertical movements (P = 0.25). No significant movements were detected on the lower arch. SN^GoGn and SPP^GoGn angles showed no significant differences between pre- and post-treatment cephalograms (P = 0.22 and P = 0.85, respectively).
  
  
  CONCLUSIONS
  Aligner therapy in association with composite attachments and class II elastics can distalize maxillary first molars by 2.25 mm without significant tipping and vertical movements of the crown. No changes to the facial height were revealed.
authors.affiliation: Post-Graduate School of Orthodontics, Lingotto - Dental School, Department of Surgical Sciences, University of Turin, Turin, Italy. serenaravera@gmail.com.
authors.forename: Serena
authors.initials: S
authors.lastname: Ravera
authors.affiliation: Post-Graduate School of Orthodontics, Lingotto - Dental School, Department of Surgical Sciences, University of Turin, Turin, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Castroflorio
authors.affiliation: Private practice, Turin, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Garino
authors.affiliation: Department of Orthodontics, Dugoni School of Dentistry, University of the Pacific, San Francisco, CA, USA.
authors.forename: Sam
authors.initials: S
authors.lastname: Daher
authors.affiliation: Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cugliari
authors.affiliation: Post-Graduate School of Orthodontics, Lingotto - Dental School, Department of Surgical Sciences, University of Turin, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Deregibus
mesh_terms: D000328:Adult; D002508:Cephalometry; D005260:Female; D006801:Humans; D008297:Male; D008963:Molar; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Adult patients; Aligners; Class II; Molar distalization