Horizontal ridge augmentation using particulate bone.

Thin alveolar ridges prevent dental implant placement. A variety of autogenous, allografts, xenografts, and alloplastic onlay grafts, alone or in different combinations, have been used to provide sufficient ridge width for proper positioning of endosseous implants. Disadvantages with the iliac crest donor site include significant resorption, patient morbidity, and high costs due to hospitalization and general anesthesia. Early placement and loading under function of dental implants within iliac crest onlay bone grafts have shown to markedly decrease progressive resorption of the graft and maintain a significant quantity of bone and a high percentage of stable functional implants over the long term. Symphyseal or ramus grafts from the mandible seem to undergo less resorption due to a thick cortical layer and rigid three-dimensional structure. Complications associated with harvesting symphyseal grafts include a limited amount of donor bone, damage to the anterior dentition, and sensory nerve disturbance in up to 10% of patients. Barrier membranes placed over bony defects allow cells from the adjacent bone to populate the space under the membrane and generate bone under the membrane. Successful lateral ridge augmentation using a combination of block and particulate symphyseal or ramus bone in conjunction with barrier membranes has been reported. Complications with membranes include tissue dehiscence, membrane displacement, and membrane collapse reducing the volume of the graft. Long-term evaluation of osseointegrated implants in vertically regenerated bone using the principles of guided bone regeneration with autograft or allograft showed that the regenerate bone responds to implant placement similar to nonregenerated bone. Particulate autogenous bone has been used to augment the mandible. Control of the surgically expanded soft tissue volume is believed to prevent resorption of graft material over the long term. With the procedure described by Marx, a full-thickness periosteal reflection of the bone is performed, and dental implants up to 15 mm in length are placed to create, control, and maintain the periosteum from the bone. Bovine bone mixed with autogenous particulate bone combined with tissue sealant (fibrin glue) has been reported as a successful method to augment the horizontal dimension of the ridge, using an open approach to place the material. Hydroxylapatite augmented ridges are infiltrated with bone several years after ridge augmentation. This osteoconductive material, when placed under periosteum using a simple tunneling technique, is eventually infiltrated with bone. Implants have been placed successfully into hydroxylapatite augmented ridges 5 to 10 years after the ridges have been augmented. Human mineralized cancellous bone can be used for preservation of ridge width after tooth extraction. By preserving the space that was previously maintained by the presence of the tooth, the particulate graft, after 4 months, has excellent ridge width and sufficient preservation to place wide-diameter implants. Severe labial bone loss was reconstructed at the time of tooth extraction with particulate material. The advantage of this material is that it is slowly resorbed