Transport disc distraction osteogenesis for the reconstruction of a calvarial defect.

PURPOSE: 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.

Use of an expanded temporoparietal fascial flap technique for total auricular reconstruction.

BACKGROUND: The authors propose an expanded technique of the temporoparietal facial flap of sufficient size to provide complete coverage in a single-stage procedure for the projected three-dimensional autogenous cartilage framework, including the tragus or lobule. METHODS: A temporoparietal fascial flap measuring 9 x 9 cm was prepared and wrapped around an expander. The expander was gradually infused with saline solution. Approximately 6 months after the first operation, a projected three-dimensional auricular framework was covered by the expanded temporoparietal fascial flap. Nine patients underwent total ear reconstruction using the expanded temporoparietal fascial flap technique. Of these, two cases were anotia, five were failed reconstructed microtia, and two were posttraumatic absence of ear. RESULTS: A final aesthetic assessment of the results was analyzed subjectively. Three cases showed excellent results, four cases showed good results, one case showed a fair result, and one case showed a poor result. CONCLUSIONS: This expansion technique is indicated in reconstruction of anotia patients who require longer and wider fascial flaps and in auricular reconstruction patients undergoing microvascular free fascial flap transfer for lessening postoperative vascular obstruction, when microvascular anastomosis is performed on the retroauricular region. The technique is also indicated in salvage auricular reconstruction for patients with an unusual vascular pattern on the temporoparietal fascial flap, or for patients showing a vascular insufficiency of the flap's distal portion after flap elevation.