About Bone Grafting
What is Bone Grafting?
Over a period of time, the jaw bone associated with missing teeth atrophies and is reabsorbed. This often leaves a condition in which there is poor quality and quantity of bone suitable for the placement of dental implants. In these situations, most patients are not candidates for the placement of dental implants.
With bone grafting we now have the opportunity to not only replace bone where it is missing, but we also have the ability to promote new bone growth in that location. 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
Missing teeth over a period of time can cause your jaw bone to atrophy, or resorb. This often results in poor quality and quantity of bone suitable for the placement of dental implants as well as long term shifting of remaining teeth and changes to facial structure. Most patients, in these situations, are not candidates for dental implants.
Fortunately, today we have the ability to grow bone where it is needed. This not only gives us the opportunity to place implants of proper length and width, but it also gives 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 are also performed to replace bone in the posterior upper jaw. In addition, special membranes may be utilized that dissolve under the gum to protect the bone graft, as well as 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 areas depending on the size needed. The skull (cranium), hip (iliac crest), and lateral knee (tibia), are common donor sites. These procedures are routinely performed in an operating room and require a hospital stay.
Types of Bone Grafts
Autogenous Bone Grafts
Autogenous bone grafts, also known as autografts, are made from your own bone, taken from somewhere else in the body. The bone is typically harvested from the chin, jaw, lower leg bone, hip, or the skull. Autogenous bone grafts are advantageous in that the graft material is your own live bone, meaning it contains living cellular elements that enhances bone growth, also eliminating the risk of your body rejecting the graft material since it comes from you.
However, one downside to the autograft is that it requires a second procedure to harvest bone from elsewhere in the body. Depending on your condition, a second procedure may not be recommended.
Allogenic bone, or allograft, is dead bone harvested from a cadaver, then processed using a freeze-dry method to extract the water via a vacuum. Unlike autogenous bone, allogenic bone cannot produce new bone on it’s own. Rather, it serves as a framework, or scaffold, over which bone from the surrounding bony walls can grow to fill the defect or void.
Xenogenic bone is derived from non-living bone of another species, usually a cow. The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.
Both allogenic and xenogenic bone grafting have an advantage of not requiring a second procedure to harvest your own bone, as with autografts. However, because these options lack autograft’s bone-forming properties, bone regeneration may take longer than with autografts, and have a less predictable outcome.
Bone Graft Substitutes
As a substitute to using real bone many synthetic materials are available as safe and proven alternatives, including:
Demineralized Bone Matrix (DBM)/Demineralized Freeze-Dried Bone Allograft (DFDBA)
This product is processed allograft bone, containing collagen, proteins, and growth factors that are extracted from the allograft bone. It is available in the form of powder, putty, chips, or as a gel that can be injected through a syringe.
Graft composites consist of other bone graft materials and growth factors to achieve the benefits of a variety of substances. Some combinations may include: collagen/ceramic composite, which closely resembles the composition of natural bone, DBM combined with bone marrow cells, which aid in the growth of new bone, or a collagen/ceramic/autograft composite.
Bone Morphogenetic Proteins
Bone morphogenetic proteins (BMPs) are proteins naturally produced in the body that promote and regulate bone formation and healing.
Synthetic materials also have the advantage of not requiring a second procedure to harvest bone, reducing risk and pain. Each bone grafting option has its own risks and benefits. Drs. Lohr or Hollabaugh will determine which type of bone graft material best suited to your particular needs.
The Importance of Teeth for Jaw Bone Health
When one or more teeth are missing it can lead to bone loss at the site of the gap. This loss of jaw bone can develop into additional problems, both with your appearance and your overall health. You may experience pain, problems with your remaining teeth, altered facial appearance, and eventually even the inability to speak and/or eat normally.
In the same way that muscles are maintained through exercise, bone tissue is maintained by use. Natural teeth are embedded in the jaw bone and stimulate the jaw bone through activities such as chewing and biting. When teeth are missing, the alveolar bone, or the portion of the jaw bone that anchors the teeth into the mouth, no longer receives the necessary stimulation it needs and begins to break down, or resorb. The body no longer uses or “needs” the jaw bone, so it deteriorates.
Potential Consequences of Tooth and Jaw Bone Loss
- Problems with remaining teeth, including misalignment, drifting, loosening, and loss
- Collapsed facial profile
- Limited lip support
- Skin wrinkling around the mouth
- Distortion of other facial features
- Jaw (TMJ or temporomandibular joint) pain, facial pain, and headaches
- Difficulty speaking and communicating
- Inadequate nutrition as a result of the inability to chew properly and painlessly
- Sinus expansion