Maxillary reconstruction using zygomatic implants: a report of two cases.

Restoration of the atrophic maxilla or a maxillary defect following tumour resection presents a challenge to the surgeon and prosthodontist. The atrophic maxilla has an inadequate denture-bearing area and also a reduced bone volume, which may contraindicate the placement of endosseous implants. The International Research Group on Reconstructive Preprosthetic Surgery reported that bone loss in edentulous jaws is related to a number of factors, including adverse loading by a prosthesis, inflammation of the overlying mucosa, vascular changes and surgery that requires elevation of a mucoperiosteal flap. Maxillary atrophy occurs in both a vertical and anteroposterior dimension, with vertical resorption increasing the inter-arch distance, resulting in functional and aesthetic problems. Anteroposterior resorption alters the maxillomandibular relationship, often creating a pseudoprognathism. The atrophied edentulous maxilla also leads to collapse of mid-face soft tissues, impaired mastication and unbalanced diet, speech difficulties, and circum-oral hypotonia. Various surgical techniques, with or without bone grafting, have been advocated for reconstruction of the atrophic maxilla. The widespread use of endosseous implants has seen an increase in bone augmentation procedures prior to implant placement. Autogenous bone grafting is accepted as the gold standard in reconstruction. The most commonly harvested free bone graft sites include the iliac crest, tibia, rib and cranium. Intra-oral sites include the mental symphysis, mandibular ramus and tuberosity. The iliac crest is the recommended donor site in maxillary reconstruction, providing an adequate volume of corticocancellous bone for both sinus elevation procedures and onlay block grafts. The placement of standard endosseous implants ideally requires bone volume in the maxillary alveolar crest of at least 10mm in height and 5mm in width. Multiple grafting procedures have been described for maxillary reconstruction, including onlay or alveolar split grafting, Le Fort I osteotomy with interpositional grafting, and sinus or nasal floor grafting. The most significant disadvantage related to iliac crest autogenous bone grafting is the second surgical site and donor site morbidity. Donor site sensory nerve deficit and scarring, gait disturbance and postoperative infection are some potential complications. Furthermore, maxillary Peer-reviewed