title: Bi-directional distraction osteogenesis of the alveolar bone using an extraosseous device.
abstract: OBJECTIVE
  In alveolar distraction, the bone segment tends to incline palatally or lingually, making rigid control of the segments difficult. The aim of this study was to evaluate the usefulness of a newly developed bi-directional extraosseous alveolar distractor (Medartis V2-Alveolar distractor) for pre- and perioperative vector management.
  
  
  METHODS
  Seven patients with segmental alveolar atrophy following traumatic tooth loss were treated using the distraction device. The patients were followed up clinically and radiologically. Preoperatively, the initial vector for distraction was determined using CT by measuring the cross-section of the bone. The morphology of the alveolar bone was also analyzed in relation to the planned implant position. Postoperatively, the rate of osteogenesis was monitored with plane radiographs and CT scan.
  
  
  RESULTS
  All cases had bone deficit at the anterior surface of the alveolar ridge, showing a typical inclination of the long axis of the bone. Using the distractor, vertical distraction and positioning of the segments with labial orientation was possible. After a consolidation period of 12 weeks on average, sufficient bone formation for implant installation was radiologically observable. Histologic and histomorphometric analysis of one bone biopsy showed very dense mineralized bone (area fraction=78%) with a multidirectional, complex architecture. Implant-supported prosthetic oral rehabilitation was successfully performed in all cases.
  
  
  CONCLUSIONS
  All complications observed in this study were related to the bone deficiency at the anterior surface of the alveolar process. If the technique can be improved, this type of bi-directional distraction is a promising method for alveolar bone repair.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, University Hospital of Berne, Berne, Switzerland. tateyuki.iizuka@insel.ch
authors.forename: Tateyuki
authors.initials: T
authors.lastname: Iizuka
authors.forename: Wock
authors.initials: W
authors.lastname: Hallermann
authors.forename: Ichiro
authors.initials: I
authors.lastname: Seto
authors.forename: Wenko
authors.initials: W
authors.lastname: Smolka
authors.forename: Koord
authors.initials: K
authors.lastname: Smolka
authors.forename: Dieter D
authors.initials: DD
authors.lastname: Bosshardt
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D000540:Alveolar Ridge Augmentation / Q000295:instrumentation*; D015519:Bone Density; D001861:Bone Regeneration; D002113:Calcification, Physiologic; D016267:External Fixators; D005260:Female; D006801:Humans; D008297:Male; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed; D014084:Tooth Avulsion / Q000150:complications