Between 1991 and 1995, 216 sinus-lift procedures were accomplished as part of a clinical study. The study involved placing 467 implants in the atrophic posterior maxillae of 142 female and 74 male patients. The initial bone height at the implant site was between 1 and 5 mm. The implants were supported subantrally with bone block grafts harvested from the retromolar or symphysis areas of the mandible. Perforations of the maxillary sinus membrane were observed in 51 patients; these were repaired with fibrin adhesive. The spaces remaining above the bone graft were filled with various materials. A total of 28 implants failed. All the remaining implants were deemed successfully osseointegrated, based on radiographic and clinical (including periodontal health) criteria. No patients experienced maxillary sinus complications. Clinically and radiographically, the best bone regeneration was observed in those patients in whom the surgically created space was completely grafted with autogenous bone that included a high percentage of resorption-resistant cortical bone. In those patients having bone grafts harvested from the mandibular symphysis, none of their facial profiles were adversely affected; however, some patients experienced neurosensory deficits involving the mandibular anterior incisors and adjacent alveolar mucosa. Occasionally, these symptoms persisted for up to 1 year following the procedure.