Bone Grafting

Major & Minor Bone Grafting

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 some cases this means that dental implants cannot be placed; in the majority of cases,however, bone can be restored that allows the 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 aesthetic appearance.

Minor Bone Grafting

Smaller areas of missing or atrophied bone in the jaws can be reconstructed by using bone taken from various sources including the patient’s own bone harvested from the jaws or by using grafting products such as allogeneic bone (sterilized, processed cadavaric bone), xenografts (sterilized, processed animal bone) and alloplastic materials (synthetic materials supporting natural bone growth).
Minor bone grafting procedures are usually performed in the office under local anesthesia and, often, with intravenous (IV) sedation to ensure comfort during the surgery.

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 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 large 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), below the knee(tibia), and even the outer skull (calverium) areused donor sites for these larger bone defects. These procedures are routinely performed in an operating room and require a hospital stay.

Sinus Lift Procedure

The maxillary sinuses are on top of the upper back teeth. Sinuses are empty spaces in the bone above the back upper teeth. They are normal structures and, when healthy, are filled only with air.Some of the roots of the upper back 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 an adequate thickness of bone to hold them in place. When the sinus wall is very thin, it is not possible to place dental implants in this bone.

There is a solution that involves grafting bone onto the “floor” of the sinus called asinus lift graft. The surgeon enters the sinus from either a small window made in the front wall of the sinus or, in some cases, through the socket where the upper teeth used to be. The sinus membrane is then gently lifted upward and the donor bone is inserted into the floor of the sinus. In many cases, if enough native bone is available, the implants can be placed at the same time as the sinus lift graft is placed, allowing both procedures to heal at the same time. In some cases, however, it will be necessary to wait until the sinus graft has healed (4 – 6 months) until the implant can be placed.

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.

Ridge Expansion

In severe cases, the ridge has been reabsorbed and a bone graft is placed to increase ridge height and/or width. This is a technique used to restore the lost bone dimension when the jaw ridge gets too thin to place conventional implants. In this procedure, the bony ridge of the jaw is literally expanded by mechanical means. Bone graft material can be placed and matured for a few months before placing the implant.

Nerve Repositioning

The inferior alveolar nerve, which gives feeling to the lower lip and chin, may need to be moved in order to make room for placement of dental implants in the lower jaw. This procedure is sometimes indicated to place implants in the back lower jaw. Since this procedure carries a high risk for temporary, or in some cases permanent, numbness of the lower lip, it is limited to cases where no other option exist to place impants in the back lower jaw.
The procedure involves removing a window of bone from the lateral lower jaw bone to expose the nerve. Once exposed, it is gently retracted out of the way so that the implants can be place without injuring the nerve. Once the implants aresecured in the bone, the nerveis released. The surgical access windowis refilled with graft material of the surgeon’s choice and the area is sutured closed.

These surgeries are performed in the out-office surgical suite under IV sedation or general anesthesia. After discharge, bed rest is recommended for one day and limited physical activity for one week.