Trans-sutural distraction osteogenesis for alveolar cleft repair: an experimental canine study.

Abstract

OBJECTIVE: To explore a new method of repair of alveolar cleft by trans-sutural distraction osteogenesis. DESIGN: Nine 8-week-old mongrel dogs were assigned randomly to two groups with three in the control group and six in the experimental group. SETTING: First, an alveolar cleft model was created surgically in all animals. After 2 weeks, a U-shaped distractor, made of nickel-titanium (NiTi) shape memory alloy wire with 200 g tensile force, was inserted into the premaxilla of the experimental dogs to distract the mid-premaxillary suture for 3 weeks. Periosteoplasty of the alveolar cleft was performed when the premaxilla at the side of cleft approached the maxilla at the same side. The distractor was removed 2 weeks post periosteoplasty. OUTCOME MEASURES: The results were evaluated clinically, radiographically, and morphologically. RESULTS: The cleft model was stable and similar to the human alveolar cleft. No spontaneous bone union occurred in the control. In experimental dogs, the premaxilla was moved slowly toward the maxilla, and the cleft became gradually narrower and closed in the third week. Radiographically, the distracted mid-premaxillary suture showed a gradually widened triangle, with the tip of the triangle pointed posteriorly. The density of the distracted triangle suture was increased gradually. The alveolar cleft was completely bony 3 months post periosteoplasty. The morphology of the mid-premaxillary suture was also restored. CONCLUSION: The alveolar cleft could be repaired by the technique of mid-premaxillary suture distraction using the elastic device of NiTi shape memory alloy.