Years ago, there were limited options to replace missing upper back teeth. Many patients had to settle for loose-fitting dentures. The sinus graft is a procedure that replaces bone between the bottom of the sinus cavity and the upper jaw. When a back tooth is lost in the upper/maxillary part of the jaw, the floor of the maxillary sinus drops down into the space that was occupied by the tooth roots. For an implant to be placed in that area, new bone height has to be created by raising or “elevating” the sinus floor and filling the space with a bone graft. New bone forms in the graft area between the sinus floor and the jawbone ridge of the upper jaw. This allows for adequate bone to support dental implant placement.