title: Continuous versus discontinuous distraction: evaluation of bone regenerate following various rhythms of distraction.
abstract: OBJECTIVE
  To investigate continuous distraction osteogenesis (DO) of the nasal bones in a rabbit model, and to compare data from this continuous DO study with data from a previously conducted discontinuous DO study. In addition, radiographic and ultrasonographic bone-fill scores were determined to investigate whether these scores provided reliable predictive value for the amount of new bone formation in the distraction area.
  
  
  METHODS
  Skeletally mature female New Zealand White rabbits were subjected to distraction of the nasal bones. A custom-made continuous distractor was used to perform automatic non-stop distraction. Bone data were obtained from radiography, ultrasonography, and microcomputed tomography. Data from this experiment were compared with data from a previous study on discontinuous distraction rhythms.
  
  
  RESULTS
  Ultrasonographic bone-fill scores correlated significantly to actual bone volume in contrast to radiographic bone-fill scores. Bone volume was significantly higher in the continuous DO group compared with the discontinuous DO groups.
  
  
  CONCLUSIONS
  Continuous distraction resulted in accelerated osteogenesis compared with discontinuous distraction. Furthermore, bone-fill scores based on ultrasonography showed a significant correlation with actual bone volumes.
authors.affiliation: Research Fellow, Department of Oral and Maxillofacial Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands. u.djasim@erasmusmc.nl
authors.forename: Urville M
authors.initials: UM
authors.lastname: Djasim
authors.forename: Eppo B
authors.initials: EB
authors.lastname: Wolvius
authors.forename: Joop A
authors.initials: JA
authors.lastname: Bos
authors.forename: Han W
authors.initials: HW
authors.lastname: van Neck
authors.forename: Karel G
authors.initials: KG
authors.lastname: van der Wal
mesh_terms: D000818:Animals; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology*; D016267:External Fixators; D005260:Female; D023421:Models, Animal; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D010012:Osteogenesis / Q000502:physiology; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods*; D011817:Rabbits; D014463:Ultrasonography; D055114:X-Ray Microtomography