title: Responses of distraction regenerate to high-frequency traction at a rapid rate.
abstract: BACKGROUND
  Continuous traction is capable of creating an optimal biological environment for bone healing which may finally compensate for the rapid distraction rate in distraction osteogenesis. This study was designed to investigate the response of distraction callus to continuous distraction at a rapid rate using a rabbit model of mandibular lengthening.
  
  
  METHODS
  Thirty adult New Zealand white rabbits were randomly assigned to the intermittent (1 step/d) or continuous distraction (8 steps/s) group, with 15 in each. After osteotomy, manual-driven or autodriven distractor was adapted accordingly. The distraction was activated at a rate of 3.0 mm/d for 4 days. Five rabbits in each group were killed at week 2, week 4, and week 12 of consolidation, respectively. Plain radiography, microcomputed tomography, and histology examinations were used to evaluate the bone regeneration status.
  
  
  RESULTS
  Plain radiographs and histologic studies demonstrated more advanced bone healing in continuous distraction group than that in intermittent distraction group at all the examined time points. Quantitative microcomputed tomography analysis showed significantly higher bone volume in continuous distraction group at week 2 (p < 0.01) and week 4 (p < 0.05) of consolidation.
  
  
  CONCLUSIONS
  Continuous traction by autodriven distractor could be a promising clinical alternative to shorten the treatment course of distraction osteogenesis. Further studies to test its clinical potential using large animals that have similar metabolic rate and muscular resistance with human being are necessary.
authors.affiliation: Discipline of Oral Diagnosis and Polyclinics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Xi Ling
authors.initials: XL
authors.lastname: Liu
authors.forename: Hua Xiang
authors.initials: HX
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Lin
authors.initials: L
authors.lastname: Peng
authors.forename: Lim Kwong
authors.initials: LK
authors.lastname: Cheung
authors.forename: Li Wu
authors.initials: LW
authors.lastname: Zheng
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology; D008334:Mandible / Q000473:pathology / Q000502:physiology; D019857:Osteogenesis, Distraction / Q000379:methods*; D010027:Osteotomy; D011817:Rabbits; D013997:Time Factors; D014143:Traction / Q000379:methods*; D055114:X-Ray Microtomography