title: Extracorporeal shock wave accelerates consolidation in distraction osteogenesis of the rat mandible.
abstract: BACKGROUND
  One of major limitations of applying distraction osteogenesis for craniofacial skeleton hypoplasia is the long duration for bony consolidation. This study investigated whether extracorporeal shock wave therapy (ESWT) could accelerate bony consolidation in distraction osteogenesis of the rat mandible.
  
  
  METHODS
  An L-shape osteotomy was performed unilaterally in the hemimandible of Sprague-Dawley rats. An internal distracter was employed to create a 7-mm distraction gap in the mandible. One hundred twenty rats were divided into three groups. The distraction zone of the mandible was received no treatment as controls (group I). Group II received ESWT (500 impulses at 14 kV) at 2 weeks postoperatively. Group III treated with 500 ESW impulses at 21 kV at 2 weeks postoperatively.
  
  
  RESULTS
  Dual-energy X-ray absorptiometry and material testing showed that optimal dosage of ESWT in group II significantly increased mineral density and enhanced biomechanical strength of the bone tissue. In histomorphological analysis, the mandibular tissue in group II showed intense osteoblastic cell recruitment, new bone formation, and vascularization. The osteoblasts in the distracted zone in group II indicated significantly strong immunoreactivities for proliferating cell nuclear antigen, vascular endothelial growth factor, and bone morphogenetic protein-2, when compared with other groups.
  
  
  CONCLUSIONS
  Optimal dosage of ESWT was beneficial for accelerating facial skeleton consolidation and bone regeneration in the distracted rat mandible tissue. The mechanism was presumably associated with the up-regulation of neovascularization, cell proliferation, and osteogenic growth factor expression in bone microenvironment.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Jui-Pin
authors.initials: JP
authors.lastname: Lai
authors.forename: Feng-Sheng
authors.initials: FS
authors.lastname: Wang
authors.forename: Chun-Min
authors.initials: CM
authors.lastname: Hung
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Wang
authors.forename: Chun-Jen
authors.initials: CJ
authors.lastname: Huang
authors.forename: Yur-Ren
authors.initials: YR
authors.lastname: Kuo
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D001861:Bone Regeneration; D004195:Disease Models, Animal; D019220:High-Energy Shock Waves; D008297:Male; D008334:Mandible / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery; D008337:Mandibular Fractures / Q000473:pathology / Q000628:therapy*; D010012:Osteogenesis / Q000528:radiation effects*; D019857:Osteogenesis, Distraction / Q000379:methods*; D010027:Osteotomy; D051381:Rats; D017207:Rats, Sprague-Dawley