Four patients underwent posterior sandwich osteotomy combined with sinus floor grafting using bone morphogenetic protein-2 and other grafting materials. The patients were treated over a period of 4 years. Two to four implants were placed in each site subsequently. Of the 12 implants placed, none failed. Alveolar crest bone levels appeared to be stable over time, with an average vertical gain of about 5 mm. Overall vertical gain, including the sinus graft, exceeded 13 mm in all patients. The procedure appears to hold promise for combined vertical alveolar defects and prominent pneumatization of the posterior maxilla.