MANDIBULAR RECONSTRUCTION WITH THE DACRON URETHANE TRAY - A RADIOLOGIC ASSESSMENT OF BONE REMODELING

A retrospective study was made of 22 consecutive patients who underwen t mandibular reconstruction with a Dacron (Osteo-mesh, Xomed Inc, Jack sonville, FL) tray technique from September 1988 to April 1992. Free a utogenous iliac bone, in the form of particulate cancellous chips and marrow, was densely packed into the Dacron tray, that was adapted to b ridge the mandibular segmental defect. Sixteen cases underwent unevent ful healing with the formation of a continuous bony bridge and union w ith the remaining mandible. The pattern of bone remodeling and rate of resorption in these cases were assessed by sequential panoramic radio graphs taken up to 3 years postoperatively. The mean horizontal dimens ion of the mandibular defects was 75 mm and the mean vertical reconstr ucted height was 25 mm. When the grafted bone was radiographically of uniform density, it progressed into a mature trabecular pattern matchi ng that of the normal mandible. However, when there were areas of radi olucency, most likely from inadequate condensation of the graft, such areas were not replaced by bone in the long term. The bony height at b oth ends and the middle of the reconstructed segment underwent reasona bly even resorption and retained about 80% of the bony height over a 3 -year period. The rate of resorption was highest in the first 6 months and stabilized at about 2 years. There were six failures, all showing significant irregular bony resorption prior to tray removal.