Autologous calvarial and iliac onlay bone grafts in miniature swine

Calvarial bone has been reported to be superior to iliac bone for onlay bone grafting due to decreased resorption. This study evaluated the physical, histologic, and radiographic characteristics of calvarial and corticocancellous iliac onlay bone grafts in nine Pitman-Moore miniature swine at 2 weeks, and at 1-, 2-, 4-, 6-, 7-, 8-, 10-, and 12-month intervals. Compared with iliac grafts, the calvarial onlay grafts had more than a twofold greater radiographic density. Statistical analysis of the mature grafts using the standard of estimated means of the bone graft volumes revealed 85% retention of the calvarial grafts compared with 34% retention of the grafted iliac bone. There was no subjective difference in the rate or degree of revascularization between the two grafted materials.