Over a period of time, the jawbone associated with missing teeth atrophies or is reabsorbed. This often results in poor quality and quantity of bone making it unsuitable for placement of dental implants. Unless corrected, the sites may not accommodate the 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 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) is a common donor site. These procedures are routinely performed in an operating room and require a hospital stay.
Bone Grafting MiniModule
For a brief narrated overview of the bone grafting process, please click the image on the right. It will launch our flash educational MiniModule in a separate window that may answer some of your questions about bone grafting.
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Sinus lift procedure
The maxillary sinuses are large spaces within the cheek bones and above the upper back teeth. 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 stabilize them in place. When the sinus wall is very thin, there is not adequate bone for the placement of implants.
The solution may be a sinus graft or sinus lift graft. A small window is made into the sinus. 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 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 that previously had no option other than wearing loose dentures.
If adequate bone between the upper jaw ridge and the bottom of the sinus is available to stabilize an implant, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not, the sinus augmentation will be performed first and allowed to mature for several months. Once the graft has matured, the implants can be placed.
Ridge Augmentation
After teeth have been removed, the bony ridges that support the teeth often become resorbed leading to a ridge that is deficient in either height or width or sometimes both. Ridge enlargement can be accomplished in a number of ways.
- Socket grafts
At the time of extraction, it is often wise to graft the dental socket with a combination of platelet rich plasma, using the patient’s own blood, and a particulate graft material. This helps maintain the ridge height and width. Keeping the normal height and width helps insure that future prostheses can be constructed leaving an esthetic and functional result.
- Grafting minor contour defects
Minor contour defects can be corrected by use of guided tissue regeneration. By reshaping the defect with a mixture of PRP and a particulate material and covered with a synthetic membrane underneath the tissue, the ridge can be restored to its normal functional width and shape. These procedures are often done in preparation for placement of implants or fixed bridges.
- Ridge expansion techniques
Thin bony ridges can often be expanded by splitting the ridge and either grafting the center of the ridge or placing a mechanical device such as a screw to maintain this width during healing. This is done in preparation for placement of dental implants.
- Grafting large bony ridge defects
Large defects in either height or width can often be corrected by grafting with the patients own bone. The bone is generally harvested from sites within the mouth such as the chin or third molar area or in more significant cases, from the hip (iliac crest). Again, these procedures are performed to enable placing both a functional and esthetic prosthesis. Some defects of ridge height can be corrected using distraction osteogenesis (please refer to the section on distraction osteogenesis).
In many cases, we can use allograft material to implement bone grafting for dental implants. This bone is prepared from cadavers and used to get the patients own bone to grow into the repair site. It is quite effective and very safe. Synthetic materials can also be used to stimulate bone formation. We even use factors from your own blood to accelerate and promote bone formation in graft areas.
These surgeries are most commonly performed in the office under IV sedation or general anesthesia. After discharge, bed rest is recommended for one day and limited physical activity for a few days.
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