|Over a period of time, the jawbone associated with missing teeth atrophies or is reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for placement of dental implants. In these situations, most patients are not candidates for immediate placement of dental implants.
Today, we have the ability to grow bone where needed. This not only gives us the opportunity to place implants of proper length and width, it also gives us a chance to restore functionality and esthetic 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. 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 and protect the bone graft and encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.
Major bone grafts are typically performed to repair defects of 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 sites depending on the size of the defect. The hip (iliac crest) and lateral knee (tibia) are the most common donor sites.
These procedures may require surgery in a hospital operating room and require a hospital stay.
Sinus Lift Procedure
The maxillary sinuses are behind your cheeks and on top of the upper teeth. Sinuses are air-filled cavities that have air and a very thin membrane lining. 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.
A sinus graft or sinus lift graft creates enough bone so implants can be placed. The dental implant surgeon exposes the area and the sinus membrane is then lifted upward and donor bone is inserted into the floor of the sinus. After a few 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. The sinus graft makes it possible for many patients to have dental implants when years ago there was no other option other than wearing loose dentures.
Sinus augmentations and implant placement can sometimes be performed as a single procedure. Enough bone must exist between the upper jaw ridge and the bottom of the sinus to stabilize the implant well. If the bone is inadequate, the Sinus Augmentation will be performed first. The graft will then mature for several months and then the implants can be placed.