Prosthetic rehabilitation of atrophic maxillary implants often requires grafting owing to vertical and transversal bone deficiency. The use of this procedure in order to insert implants was introduced by Tatum and published as a clinical study by Boyne and James. It can be performed via a lateral or crestal approach. This surgery is now widespread, with good results in terms of bone augmentation and implant osseointegration. Nevertheless, there is a small proportion of patients who have infectious complications with an incidence ranging from 3.5% to 10.5%. We observe that maxillary sinus augmentation is a successful preprosthetic technique for augmentation of the edentulous posterior maxilla. Preoperative assessment of the anatomy of the sinus reduces the rate of complications considerably.