Missing teeth over a period of time can cause your jaw bone to atrophy, or resorb. This often results in poor quality and quantity of bone suitable for the placement of dental implants as well as long-term shifting of remaining teeth and changes to facial structure. Most patients, in these situations, are not candidates for dental implants.
Fortunately, today we have the ability to grow bone where it is needed. This not only gives us the opportunity to place implants of proper length and width, but it also gives us a chance to restore functionality and aesthetic appearance.
Major Bone Grafting
Bone grafting can repair implant sites with inadequate bone structure due to previous extractions, gum disease, or injuries. The bone is either obtained from a tissue bank or your own bone is taken from the jaw, hip, or tibia (below the knee). Sinus bone grafts are also performed to replace bone in the posterior upper jaw. In addition, special membranes may be utilized that dissolve under the gum to protect the bone graft, as well as encourage bone regeneration. This is called guided bone regeneration, or guided tissue regeneration.
Major bone grafts are typically performed to repair defects in the jaws. These defects may arise as a result of traumatic injuries, tumor surgery, or congenital defects. Large defects are repaired using the patient’s own bone. This bone is harvested from a number of different areas depending on the size needed. The skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are routinely performed in an operating room and require a hospital stay.
Bone grafting for implants
After tooth extraction, if the walls of the socket are very thick, they will usually fill naturally with bone in two to three months. However, when the walls of your socket are very thin (such as in your upper and lower front teeth), this type of healing will not be as predictable. In these situations, a bone graft is often placed at the time of tooth extraction to help your body fill in the empty socket with bone. This step will maintain the width and volume of bone you will need for implant placement several months later.
There may be inadequate bone for implant placement if your tooth was removed many years ago and your bony ridge is extremely thin. In this case, a bone graft can be placed next to the thin bone and allowed to heal for up to six months. After the graft has fused to your pre-existing bone, the ridge will be re-entered and the implant placed. Bone grafting is usually a relatively comfortable office procedure. Many different bone-grafting materials are available, including your own bone.
You may also need bone grafting if the sinus cavities in your upper jaw are very large, or very low, and extend into the tooth-bearing areas. This often occurs when teeth in the back of a person’s upper jaw have been removed many years before, and the amount of bone available for implant placement is limited. A “sinus grafting procedure” is then required. Most often, it is performed in the office with local anesthesia and perhaps sedation. During this procedure, the membrane that lines the sinus will be located and elevated. Bone will then be added to restore the bone height and ensure that dental implants of an adequate length can be placed. This procedure often can be performed at the time of implant placement.