Dental implants need bone to hold them in place. When the sinus wall is very thin, it is impossible to place dental implants in this bone. There is a solution called a sinus graft or sinus lift graft. During this procedure, your periodontist enters the sinus from where the upper teeth used to be. The sinus membrane is then lifted upward and donor bone is inserted into the floor of the sinus. The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option other than wearing partial dentures.