Autogenous bone grafts in the rabbit maxillary sinus

Objective. This study involving rabbits was undertaken to establish an experimental model for the sinus lift procedure and to clarify the repair of autogenous grafted bone in the maxillary sinus. Study design. A corticocancellous bone block was grafted into the maxillary sinus of each of 18 rabbits. Each animal was killed at 2, 4, or 8 weeks after grafting and then histologically evaluated. Results. At 2 weeks, new bone formation was observed. There was no inflammation of the antral membrane. At 4 weeks, lamellar structures were observed in newly formed bone. At 8 weeks, newly formed cortical bone was observed under the elevated membrane and the medullary cavity was almost completely occupied by fat cells. Conclusions. There were no histologic complications after the sinus lift procedure. Histologic results indicated that newly continuous cortical bone was formed along the elevated membrane at 8 weeks. This animal model could be useful as a sinus lift model.