Induced osteogenesis in the repair of experimental mandibular defects in rats.

In order to investigate the repair of mandibular defects, we have devised a nonhealing model in the ramus of the rat mandible. The large full thickness defects, devoid of periosteum, were filled with demineralized bone powder (DBP), lyophilized bone chips, and un-demineralized bone powder (BP) or were irrigated with Ringer's lactate. Healing was judged by gross and histologic examination and by incorporation fo 45 calcium into hydropyapatite. DBP produced more rapid and complete healing than did BP or lyophilized chips. DBP did not undergo appreciable resorption prior to bone formation and was a more potent osteogenic stimulus than was BP or lyophilized chips.