Onlay Bone Grafting
autogenous rib was first described by Terry, Albright, and Baker.U Maxillary onlay bone grafttng is indicated primarily when severe resorption of the maxillary alveolus is seen that results in the absence of a clinical alveolar ridge and loss of adequate palatal vault fmlll.22 Maxillary onlay grafting currently -is usually accomplrshed using corticocancellous blocks of iliac crest bone.- The blocks can he secured to the maxilla with small screws, eliminating mobility and decreasing resorption (Fig. 13-34). Cancellous bone is then packed around the grafts to improve contour. Implants can be placed at the time of grafting in some cases, but placement is.

skin-grafting procedure has been done after HA augmentation to improve vestibular depth.)
G, Postoperative radiograph demonstrating improvement in height of alveolar ridge area.

photograph. C, Three seqrnents of bo~e are secured in place. Small defects are filled with cancellous
bone. 0, Clinical photograph.