title: Treatment outcome and efficacy of an aligner technique--regarding incisor torque, premolar derotation and molar distalization.
abstract: BACKGROUND
  The aim of this study was to investigate the efficacy of orthodontic treatment using the Invisalign® system. Particularly, we analyzed the influence of auxiliaries (Attachment/Power Ridge) as well as the staging (movement per aligner) on treatment efficacy.
  
  
  METHODS
  We reviewed the tooth movements of 30 consecutive patients who required orthodontic treatment with Invisalign®. In all patients, one of the following tooth movements was performed: (1) Incisor Torque >10°, (2) Premolar derotation >10° (3) Molar distalization >1.5 mm. The groups (1)-(3) were subdivided: in the first subgroup (a) the movements were supported with the use of an attachment, while in the subgroup (b) no auxiliaries were used (except incisor torque, in which Power Ridges were used). All tooth movements were performed in a split-mouth design. To analyze the clinical efficacy, pre-treatment and final plaster cast models were laser-scanned and the achieved tooth movement was determined by way of a surface/surface matching algorithm. The results were compared with the amount of tooth movement predicted by ClinCheck®.
  
  
  RESULTS
  The overall mean efficacy was 59% (SD = 0.2). The mean accuracy for upper incisor torque was 42% (SD = 0.2). Premolar derotation showed the lowest accuracy with approximately 40% (SD = 0.3). Distalization of an upper molar was the most effective movement, with efficacy approximately 87% (SD = 0.2).
  
  
  CONCLUSIONS
  Incisor torque, premolar derotation and molar distalization can be performed using Invisalign® aligners. The staging (movement/aligner) and the total amount of planned movement have an significant impact on treatment efficacy.
authors.affiliation: Oral Technology Medical Faculty, Dental School, University of Bonn, Welschnonnenstr, 17 53111 Bonn, Germany. mareike.simon@uniklinik-freiburg.de.
authors.forename: Mareike
authors.initials: M
authors.lastname: Simon
authors.forename: Ludger
authors.initials: L
authors.lastname: Keilig
authors.forename: Jörg
authors.initials: J
authors.lastname: Schwarze
authors.forename: Britta A
authors.initials: BA
authors.lastname: Jung
authors.forename: Christoph
authors.initials: C
authors.lastname: Bourauel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001641:Bicuspid / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006696:Holography / Q000295:instrumentation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000473:pathology*; D007834:Lasers; D008297:Male; D008310:Malocclusion / Q000473:pathology / Q000628:therapy; D008875:Middle Aged; D003765:Models, Dental; D008963:Molar / Q000473:pathology*; D016382:Orthodontic Appliance Design; D012189:Retrospective Studies; D012399:Rotation; D014087:Tooth Movement Techniques / Q000295:instrumentation*; D019415:Torque; D016896:Treatment Outcome; D014584:User-Computer Interface; D055815:Young Adult