Distraction osteogenesis of the palate: an experimental model.

Abstract

Although most cleft palates can be closed with conventional mucoperiosteal flap techniques, the occasional wide cleft or difficult fistula has few options for an early 1-stage reconstruction. Distraction osteogenesis (DO) has the potential to close the palate with both hard and soft tissues as well as mitigating the possibility of future oronasal fistula. A right unilateral 5-mm cleft was surgically created in 15 New Zealand white rabbits. In group 1 (N = 5), no further repair was performed (NR); in group 2 (N = 5), mucoperiosteal flaps were used to close the cleft for a soft-tissue-only repair (STR); in group 3 (N = 5), a unilateral osteotomy in the palate on the noncleft side allowed distraction of the palatal shelf across the cleft until closed (DO). Clinical examination, Micro-computed tomography bone density, direct cephalometry, and histology were evaluated at 8 weeks after the completion of distraction. Bone mineral density (BMD; mg/mL) data were obtained from micro-computed tomography scans of both the cleft and noncleft sides for each rabbit, and a ratio was obtained [(BMDc/BMDnc) x100]; NR = 1.38, STR = 44.27, DO = 88.36, P = 0.007. Facial measurements revealed no growth disturbances as a result of DO. Histologic evaluation revealed increased organization of new bone in DO group compared with NR and STR. Clinically, DO group rabbits did not show any increase in feeding disturbances, infection, or wound healing. The success of membranous facial bone distraction has been applied to a new model for palatal repair with the potential to ameliorate the problems associated with soft-tissue-only repair.