Major & Minor Bone Grafting
Over 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 situations such as these, patients may not be candidates for the placement of dental implants.
Today, we have the ability to grow bone where needed. This can not only give us the opportunity to place implants of proper length and width, it can also give 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 can also be performed to replace bone in the posterior upper jaw. In addition, special membranes can be utilized that dissolve under the gum and protect the bone graft and promote 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 skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are generally performed in an operating room and may require a hospital stay.
Sinus Lift Procedure
The maxillary sinuses are behind your cheeks and on top of the upper teeth. Sinuses are like empty rooms that have nothing in them. 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 require bone to anchor them in place. When the sinus wall is very thin, it is impossible to place dental implants in this bone.
The solution to this is called a sinus graft or sinus lift graft. Dr. Akin 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 (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.
This procedure makes it possible for many patients to have dental implants when years ago there was no other option other than wearing poorly fitted dentures.
If the bone between the upper jaw ridge and the bottom of the sinus is sufficient to stabilize the implant well, sinus augmentations and implant placement can sometimes be performed as a single procedure. If not enough bone is available, the sinus augmentation will have to be performed first, then the graft will need to mature for several months, depending upon the type of graft material used. Once the graft has matured, the implants can be placed.
In severe cases, the ridge has been reabsorbed and a bone graft must be placed to increase ridge height and/or width. This technique is used to restore lost bone dimension when the jaw ridge becomes too thin to place conventional implants. In this procedure, the bony ridge of the jaw is expanded by mechanical means. Bone graft material can be placed and matured for a few months before placing the implant.
The inferior alveolar nerve, which gives feeling to the lower lip and chin, may require repositioning in order to make room for the placement of dental implants in the lower jaw. This procedure is limited to the lower jaw and is indicated when teeth are missing in the area of the two back molars and/or and second premolar. Since this procedure is considered a very aggressive approach (there is almost always some postoperative numbness of the lower lip and jaw area, which dissipates only very slowly, if ever), usually other, less aggressive options are considered first.
Typically, an outer section of the cheek side of the lower jawbone is removed in order to expose the nerve and vessel canal. The nerve and vessel bundle in that area is then isolated and pulled slightly out to the side. At the same time, the implants are put in place. The bundle is then released and placed back over the implants. The surgical access is refilled with bone graft material and the area is closed.
These procedures may be performed separately or together, depending upon the individual circumstances. There are several areas of the body that are suitable for attaining bone grafts. In the maxillofacial region, bone grafts can be taken from inside the mouth, in the area of the chin or third molar region, or in the upper jaw behind the last tooth. In more extensive situations, a larger quantity of bone can be attained from the hip or the outer aspect of the tibia at the knee. Optimum results are generally achieved when patient’s own bone is used for repairs.
In many cases, allograft material can be used to implement bone grafting for dental implants. This bone is prepared from cadavers and used to promote the patients own bone to grow into the repair site. This is quite effective and very safe. Synthetic materials can also be used to stimulate bone formation. Factors from your own blood can also be used to accelerate and promote bone formation in graft areas.
These surgeries are performed in a hospital environment under IV sedation or general anesthesia. After discharge, bed rest is recommended for one day and limited physical activity for one week.