title: Transport disc distraction osteogenesis for the reconstruction of a calvarial defect.
abstract: OBJECTIVE
  According to previous reports about the experimental study of transport disk distraction osteogenesis (TDDO) for the reconstruction of bone defects, TDDO showed great feasibility of successful bone regeneration. However, those studies had some limitations in their design and analysis of the results, either. In this report, we intended to verify the effect of TDDO in the reconstruction of skull defects with a combined result of distraction osteogenesis and bone graft of transported disk (TD).
  
  
  METHODS
  Six female dogs were operated on and were given a 35×15-mm bilateral skull defect. In the experimental group, TDDO with internal distractors (7×14-mm TD) was performed. On the other side, in the control group, the bone defects were left to heal naturally. The distraction was performed from the postoperative fifth day at a rate of 1 mm/d. The distraction progressed for 14 days, and then the TD was maintained in the middle of the bone defect area. The 40% of the original bone defect area was left the same as the control side. The TD was expected to be survived as a bone graft during the consolidation period. After 3½ months of a consolidation period, the remained bone defects were measured by three-dimensional computed tomography. The solidity of the new bone was compared with the bone tissue of the normal skull bone.
  
  
  RESULTS
  In the study group, the new bone formation was estimated to be 62.3% (SD, 25.1%) of the defect area, and in the control group, it was 44.8% (SD, 27.3%). The difference between the 2 groups was significant (P=0.04). The solidity of the newly generated bone by TDDO was not different from the normal skull (P=0.74).
  
  
  CONCLUSIONS
  In this study, the concept of TDDO and bone graft seemed to promote new bone formation. The role of the TD could include bone regeneration from distraction osteogenesis as well as autogenous bone graft, although it needs more investigation. The relationship between the duration of distraction and the positive role of the TD as an autogenous bone graft in TDDO for better clinical application may be investigated.
authors.affiliation: Department of Plastic & Reconstructive Surgery, Institute for Human Tissue Restoration, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: In Sik
authors.initials: IS
authors.lastname: Yun
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Mun
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Hong
authors.forename: Eul Je
authors.initials: EJ
authors.lastname: Cho
authors.forename: Dae Gon
authors.initials: DG
authors.lastname: Woo
authors.forename: Han Sung
authors.initials: HS
authors.lastname: Kim
authors.forename: Yong Oock
authors.initials: YO
authors.lastname: Kim
authors.forename: Be-young Yun
authors.initials: BY
authors.lastname: Park
authors.forename: Dong Kyun
authors.initials: DK
authors.lastname: Rah
mesh_terms: D000818:Animals; D001863:Bone Screws; D016025:Bone Transplantation; D004285:Dogs; D005260:Female; D021621:Imaging, Three-Dimensional; D019857:Osteogenesis, Distraction / Q000295:instrumentation / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012886:Skull / Q000601:surgery*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D014945:Wound Healing