When replacing posterior upper teeth with dental implants, one of the limiting factors is the amount of bone available between the gum and the maxillary sinus. The maxillary sinus is essentially an air space within the upper cheek bone. If there is insufficient bone to allow for the placement of an implant, we may suggest a procedure called a sinus augmentation, sometimes known as a "sinus lift". During this procedure, the sinus membrane is lifted upward and donor bone is inserted into the floor of the sinus. After several months of healing, the bone becomes part of the patient's jaw and dental implants can be inserted and stabilized in this new sinus bone. Routine dental implant procedures can then be performed.