On each side of the top jaw, above the roots of the back teeth, there is a small air-filled cavity, called the sinus. The amount of bone between the back teeth and the sinus is often limited, especially after a tooth has been lost. A “sinus lift” procedure will augment the bone under the sinus area, to create sufficient bone height and width to properly place and support an implant. Two sinus lift approaches are possible.
The first is the lateral approach, where the periodontist makes a small opening in the gums near the sinus and inserts mineral particles (synthetic or natural bone) under the lining of the sinus. The opening is then carefully closed with a membrane under the gums. Depending on how much bone is available at the time of the sinus lift, implants may be placed immediately, or after waiting a few months for the new bone to mature. Before placing an implant, a small opening that has the implant shape and size has to be drilled in the bone.
In the second method, the crestal approach, the mineral particles are inserted under the sinus lining, through this opening. This procedure is usually performed just before the implant is inserted.