title: The fate of developing teeth in mandibular lengthening by distraction: an experimental study.
abstract: OBJECTIVE
  The purpose of this study was to observe developing teeth in a lengthened mandible after distraction.
  
  
  METHODS
  Ten mongrel dogs with deciduous dentitions were used.
  
  
  METHODS
  A corticotomy was carefully made around a tooth bud and the external distractor (Orthofix M-100) was connected. After a 5-day latent period, distraction was started at a rate of 0.75 mm per day for 10 consecutive days. Then, the lower jaw was stabilized by an external fixation to allow ossification. While the operation was performed on the left side (Distraction group), the contralateral side was studied for comparison (Control). In addition, a corticotomy, artificial fracture and external fixation were carried out to confirm the influence of the operation (Fracture group). Then macroscopic, radiographic and histological evaluations were carried out.
  
  
  RESULTS
  In the Distraction group, the space between the wall of the dental follicle and the crown expanded as distraction began. The end of the calcified root became wider and irregular during the distraction period, and finally, the apex closed. In the Fracture group, the teeth erupted although slight alterations of the root shape were observed in association with the operation period.
  
  
  CONCLUSIONS
  The root became irregular, but the teeth erupted within the distraction area.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine, Japan. hhiroko@rk9.so-net.ne.jp
authors.forename: H
authors.initials: H
authors.lastname: Hagino
authors.forename: Y
authors.initials: Y
authors.lastname: Sawaki
authors.forename: M
authors.initials: M
authors.lastname: Ueda
mesh_terms: D000818:Animals; D003795:Dental Sac / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D004285:Dogs; D016267:External Fixators; D005592:Fracture Fixation / Q000295:instrumentation; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008337:Mandibular Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology; D009805:Odontogenesis / Q000502:physiology*; D010012:Osteogenesis; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods; D010027:Osteotomy / Q000379:methods; D011859:Radiography; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014074:Tooth Calcification / Q000502:physiology; D019228:Tooth Crown / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014078:Tooth Eruption / Q000502:physiology; D014083:Tooth Germ / Q000473:pathology / Q000503:physiopathology*; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology