Symphysis revisited: clinical and histologic evaluation of newly formed bone and reharvesting potential of previously used symphysial donor sites for onlay bone grafting.

Background: This article reports on the reharvesting potential of newly formed bone in previously used symphysial donor sites.

Methods: This study included five patients who were scheduled for sequential onlay bone augmentations prior to dental implant placement using the symphysis area as a donor site. At 5 months after bone augmentation, computed tomography scans of donor sites revealed healing from the first surgery. Because additional bone augmentation was required, the same sites were revisited for bone harvesting. Reharvesting was performed 5 months after the first harvesting. A small portion of the harvested bone from two patients was evaluated histologically.

Results: Five months postharvesting, clinical observation of the donor sites resembled newly formed bone as a conglomerate of bovine bone particles. In the five patients, bone continuity was observed between new bone at the donor defect sites and surrounding bone. Additional blocks were reharvested from the same sites and successfully grafted to recipient sites. Dental implants were inserted 5 months after the second augmentation, which healed uneventfully. Histologically, bovine bone particles were surrounded by woven bone, with areas of mature bone with well-organized osteons.

Conclusions: Remodeling of a symphysial donor area enabled reuse of the site for additional harvesting. Intraoral bone sources could serve as a long-lasting renewable source of high-quality bone.