The back part of the upper jaw is an area where there is often inadequate bone for dental implants. The reason for this is the existence of a large air cavity called the sinus. There are different techniques to graft bone in this region. Sinus lifting can refer to expanding some of your own bone in to the sinus cavity or adding bone in to the sinus. Often, dental implants can be placed at the same time. This procedure, though not as routine as just placing dental implants, is not a big deal and has very few possible complications.