Bone Grafting

Sinus Lifting: Dental Implants

A sinus lift, sometimes called a sinus augmentation, is surgery that adds bone to your upper jaw in the area of your molars and premolars to make it taller. The bone is added between your jaw and the maxillary sinuses, which are on either side of your nose. To make room for the bone, the sinus membrane has to be moved upward, or “lifted.”

A sinus lift is done when there is not enough bone in the upper jaw, or the sinuses are too close to the jaw, for dental implants to be placed.

There are several reasons for this:

° Many people who have lost teeth in their upper jaw particularly the back teeth, or molars do not have enough bone for implants to be placed;° Because of the anatomy of the skull, the back of the upper jaw has less bone than the lower jaw;

° Bone may have been lost because of periodontal (gum) disease;

° Once teeth are gone, bone begins to be resorbed (absorbed back into the body). If teeth have been missing for a long time, there often is not enough bone left to place implants;

° The maxillary sinus may be too close to the upper jaw for implants to be placed. The shape and the size of this sinus varies among individuals. In addition, the sinus can get larger as we age.

How It’s Done

Your surgeon will cut the gum tissue near your premolars and molars. The tissue is raised, exposing the bone. A small, oval window is opened in the bone.

The membrane lining the sinus on the other side of the window separates your sinus from your jaw. This membrane is gently pushed up and away from your jaw. Granules of bone-graft material are then packed into the space where the sinus was. The amount of bone used will vary, but usually several millimeters of bone is added above the jaw.

Once the bone is in place, the tissue is stitched closed. Your implants will be placed four to nine months later, depending on the graft material that was used. This allows time for the grafted material to mesh with your bone. 

Sinus lifts have become common over the past 15 years as more people are getting dental implants to replace missing teeth.

The bone used in a sinus lift may come from your own body (autogenous bone) or from a cadaver (allogeneic bone). Synthetic materials, which can stimulate bone formation, also are used sometimes.

If your own bone will be used in the sinus lift, it will be taken from other areas of your mouth or body. In some cases, the surgeon removes bone from your hip or your tibia (the bone beneath the knee).

You may need X-rays taken before your sinus lift so the dentist can study the anatomy of your jaw and sinus. You also may need a special type of computed tomography (CT) scan to accurately measure the height and width of your existing bone and to evaluate the health of your sinus.