Chin augmentation with porous hydroxyapatite blocks.

The results of chin augmentation by porous hydroxyapatite blocks were evaluated clinically and radiographically in nine patients. Recovery of a satisfactory facial profile was achieved by the procedure, and all patients but one, with removal of the implant because of infection, were satisfied with the results of the surgery. Radiographically, the implants were incorporated into the bony structure of the mandible by deposition of bone at and around the bone-implant interface and ingrowth of bone into pores. Cephalometrically, the procedure was found to provide very stable results, with little change in the position of the implants and no appreciable resorption of the implants and bone. Despite heavy chemotherapy, histologic examination of the removed hydroxyapatite showed the presence of areas with numerous inflammatory cell infiltration and no bone formation. Thus, the procedure is quite useful for chin augmentation, but utmost care should be taken to avoid infection.