[Four years after augmentation of the resorbed mandibular alveolar ridge with hydroxylapatite granules]

In seven patients with an onlay of hydroxylapatite granules on the severely resorbed mandible the results are reported after four years. Radiographic evaluation showed some loss (a median loss of 7%) of height of the onlay in five of the seven patients. The granules in the upper part of the onlay proved to be smaller, probably as a result of fragmentation. The underlying bone, however, had remained unchanged.