title: Three-dimensional prospective evaluation of tooth-borne and bone-borne surgically assisted rapid maxillary expansion.
abstract: OBJECTIVE
  To three-dimensionally (3D) assess the long-term effects of tooth-borne and bone-borne surgically assisted rapid maxillary expansion (SARME).
  
  
  METHODS
  This prospective cohort study comprised 45 consecutive skeletally mature non-syndromic patients with transverse maxillary hypoplasia. In 28 patients, a tooth-borne distractor (Hyrax) was used for expansion, whereas in the remaining 17 a bone-borne distractor (transpalatal distractor, TPD) was used. Cone beam computed tomography (CBCT) scans were performed before treatment (T0) and 22 months later, after fixed appliance treatment (T1). 3D models were constructed from CBCT data and superimposed using voxel-based matching. Distance maps between the superimposed models were computed to evaluate the amount of skeletal changes.
  
  
  RESULTS
  The distance maps of the superimposed models showed positive distances on the right and left posterior alveolar segments of the maxilla indicating lateral expansion. The anterior maxillary region showed negative distances or posterior displacement and remodelling of the anterior alveolar region. There was no statistically significant difference between TPD and Hyrax for the three alveolar segments (p values ranged 0.63-0.81).
  
  
  CONCLUSIONS
  Bone-borne and tooth-borne SARME were found to produce comparable results at the end of fixed appliance treatment regarding skeletal changes.
authors.affiliation: Department of Orthodontics and Craniofacial Biology, Radboud University Nijmegen Medical Centre, The Netherlands.
authors.forename: Rania M
authors.initials: RM
authors.lastname: Nada
authors.forename: Piotr S
authors.initials: PS
authors.lastname: Fudalej
authors.forename: Thomas J J
authors.initials: TJ
authors.lastname: Maal
authors.forename: Stefaan J
authors.initials: SJ
authors.lastname: Bergé
authors.forename: Yehya A
authors.initials: YA
authors.lastname: Mostafa
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
mesh_terms: D000328:Adult; D000539:Alveolar Process / Q000473:pathology; D001641:Bicuspid / Q000473:pathology; D016723:Bone Remodeling / Q000502:physiology; D002508:Cephalometry / Q000379:methods; D015331:Cohort Studies; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003481:Cuspid / Q000473:pathology; D003724:Dental Arch / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008963:Molar / Q000473:pathology; D016382:Orthodontic Appliance Design; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D019340:Osteotomy, Le Fort / Q000379:methods; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D011446:Prospective Studies; D055815:Young Adult