title: Integrated three-dimensional digital assessment of accuracy of anterior tooth movement using clear aligners.
abstract: OBJECTIVE
  To assess the accuracy of anterior tooth movement using clear aligners in integrated three-dimensional digital models.
  
  
  METHODS
  Cone-beam computed tomography was performed before and after treatment with clear aligners in 32 patients. Plaster casts were laser-scanned for virtual setup and aligner fabrication. Differences in predicted and achieved root and crown positions of anterior teeth were compared on superimposed maxillofacial digital images and virtual models and analyzed by Student's t-test.
  
  
  RESULTS
  The mean discrepancies in maxillary and mandibular crown positions were 0.376 ± 0.041 mm and 0.398 ± 0.037 mm, respectively. Maxillary and mandibular root positions differed by 2.062 ± 0.128 mm and 1.941 ± 0.154 mm, respectively.
  
  
  CONCLUSIONS
  Crowns but not roots of anterior teeth can be moved to designated positions using clear aligners, because these appliances cause tooth movement by tilting motion.
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing, China. ; Department of Orthodontics, Luhe Hospital of China Capital Medical University, Beijing, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Zhang
authors.affiliation: Department of Orthodontics, Yan'an University Affiliated Hospital, Yan'an, China.
authors.forename: Li
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing, China.
authors.forename: Hong-Ming
authors.initials: HM
authors.lastname: Guo
authors.affiliation: Private Practice, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing, China.
authors.forename: Yu-Xing
authors.initials: YX
authors.lastname: Bai
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing, China.
authors.forename: Song
authors.initials: S
authors.lastname: Li
keywords: Clear aligners; Cone-beam computed tomography; Registration