The maxillary sinuses are behind your cheeks and on top of the upper teeth. These sinuses are empty, air-filled spaces. Some of the roots of the natural upper teeth extend up into the maxillary sinuses. When these upper teeth are removed, there is often just a thin wall of bone separating the maxillary sinus and the mouth. 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.
The key to a successful and long-lasting dental implant is the quality and quantity of jaw bone to which the implant will be attached. If bone loss has occurred due to injury or periodontal disease, a sinus augmentation can raise the sinus floor and allow for new bone formation.
In the most common sinus augmentation procedure, a small incision is made on the premolar or molar region to expose the jaw bone. A small opening is cut into the bone, and the membrane lining the sinus is pushed upward. The underlying space is filled with bone grafting material, either from your own body or from a cadaver. Sometimes, synthetic materials that can imitate bone formation are used. After the bone is implanted, the incision is stitched up and the healing process begins. After several months of healing, the bone becomes part of the patient’s jaw and dental implants can be inserted and stabilized in this new sinus bone.
If enough bone between the upper jaw ridge and the bottom of the sinus is available to stabilize the implant well, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation will have to be performed first, then the graft will have to mature for several months, depending upon the type of graft material used. Once the graft has matured, the implants can be placed.
The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option besides wearing loose dentures.