Closure of vertical alveolar bone defects with guided horizontal distraction osteogenesis: an experimental study in pigs and first clinical results

Purpose: To evaluate the option of treating alveolar clefts by guided distraction osteogenesis instead of applying osteoplasty with autologous bone grafts from iliac crest, rib or fibula. Material and Methods: At first, 30 land-bred pigs were operated upon. Treatment of each animal included creating bony defects measuring 2, 4 or 8 mm in the maxilla, anterior to the canine region and up to the nasal periosteum. In 15 of the 30 animals, a new horizontal segment distractor was tested. The device was placed in situ prior to creating an alveolar segment posterior to the defect. This segment was then transported gradually by distraction, thus crossing and closing the defect. At the end of the distraction and stabilization periods the newly formed bony tissue was examined. Results: The critical size of defects was found to be larger than 4 mm. In five of six animals with a horizontal defect of 8 mm, complete ossification of the defect had occurred following distraction osteogenesis. This technique was then applied to five patients successfully. Conclusion: It was shown that distraction osteogenesis is a valid alternative for treating alveolar clefts.