Over a period of time, the jawbone associated with missing teeth atrophies or is resorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for placement of dental implants. In these situations, patients may require a grafting procedure to be candidates for placement of dental implants.
Today, we have the ability to grow bone where needed. This gives us the opportunity not only to place implants of proper length and width, but also to restore functionality and aesthetic appearance.
Bone grafting can repair implant sites that have inadequate bone structure due to previous extractions, gum disease or injuries. The bone can be the patient’s own bone taken from elsewhere in the jaw. More commonly, special membranes can be utilized that dissolve under the gum and protect an artificial bone graft placed in order to encourage bone regeneration. This is called guided bone regeneration or guided tissue regeneration.
Minor Bone Grafts
For small bone defects, guided bone regeneration can be employed. Materials for this can include tissue-bank bone (freeze-dried bone), bovine bone, synthetic substitutes and a special bone-growing membrane. The graft material and membrane are resorbed with time, and new bone grows in the grafted area. A substance called bone morphogenic protein (BMP-2) can also be used to induce bone growth.
This grafting can be used for the following:
Major Bone Grafts
Large bone defects can require an autogenous graft, or use of the patient’s own bone. These larger defects can be created by injuries, congenital defects, tumor surgery or early loss of teeth.
The autogenous bone can be obtained from different sites of the body, depending on how much bone is required. For smaller defects, sites such as the chin or wisdom tooth area of the lower jaw can be used. For larger areas, donor sites from the hip and tibia (lateral knee) can be used.
Sinus Lift Graft
The maxillary sinuses are behind the cheeks and on top of the upper posterior teeth. Maxillary sinuses are air spaces of the mid-face that act to humidify air and have evolved as shock absorbers in case of facial trauma. They are like empty rooms that have nothing in them. Some of the roots of the natural 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.
One solution is called a sinus augmentation or sinus lift graft: The surgeon enters the sinus from where the upper teeth used to be. The sinus membrane is then lifted upward, and donor bone is inserted into the floor of the sinus. Keep in mind that the floor of the sinus is the roof of the upper jaw. After several months of healing, the bone becomes part of the patient’s jaw. 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 option other than wearing loose dentures.
If enough bone between the upper-jaw ridge and the bottom of the sinus is available to stabilize the implant well, sinus augmentation and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation has to be performed first; then the graft has to mature for several months before the implant can be placed.
Ridge expansion is an alternate technique that can be used in cases where the jaw ridge is too thin to place implants. The jaw ridge is sectioned and expanded with special instruments. Bone-graft material is placed between the expanded sections of bone and heals for a few months prior to implant placement. In some cases, implants can be placed simultaneously.
You may find some small granules in your mouth for the first several days. Do not be alarmed by these. It’s normal to have some of them come out of the graft site and into your mouth.
On the first day: LET THE BLOOD CLOT STABILIZE. DO NOT EVEN RINSE YOUR MOUTH.
Following the first day:
Call our office if you have any problems or questions concerning your surgery.
Risks & Side Effects
As with any surgery, there is a possibility that a bone graft may fail – even when your own bone is used. Infection may develop, or the grafted bone may come loose from your jaw. Smokers and people with certain other medical conditions generally have a higher risk of graft failure than most patients. Failed grafts must be removed, and the site must be allowed to heal before a second graft can be attempted.