Bone Grafting

About Bone Grafting | Types of Grafts | Bone Graft Substitutes | About Jawbone Health | Reasons for Jawbone Loss

What is Bone Grafting?

Over time, the jawbone associated with missing teeth atrophies and is reabsorbed. This often leaves a condition in which the quality and quantity of bone suitable for dental implant placement are poor. In these situations, most patients are not candidates for the placement of dental implants.

With bone grafting, we can not only replace bones where they are missing, but we also can promote new bone growth in that location. This not only allows us to place implants of proper length and width, but it also gives us a chance to restore functionality and aesthetic appearance.

Major & Minor Bone Grafting

Missing teeth over a period of time can cause your jawbone 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.

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 skull. Autogenous bone grafts are advantageous in that the graft material is your own live bone, meaning it contains living cellular elements that enhance 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

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 its 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.

Xenogeneic Bone

Xenogeneic 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, xenogeneic grafts serve as a framework for bone from the surrounding area to grow and fill the void.

Both allogenic and xenogeneic bone grafting have the 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 for using real bones, 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

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. Dr. Galante will determine which type of bone graft material best suits your needs.

The Importance of Teeth for Jawbone Health

When one or more teeth are missing, it can lead to bone loss at the site of the gap. This loss of jawbone 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 jawbone and stimulate the jawbone through activities such as chewing and biting. When teeth are missing, the alveolar bone, or the portion of the jawbone 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 jawbone, so it deteriorates.

Potential Consequences of Tooth and Jawbone 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 because of the inability to chew properly and painlessly
• Sinus expansion

Reasons for Jawbone Loss and Deterioration

The following are the most common causes for jawbone deterioration and loss that may require a bone grafting procedure:

Tooth Extractions

When an adult tooth is removed and not replaced, jawbone deterioration may occur. Natural teeth are embedded in the jawbone and stimulate the jawbone through activities such as chewing and biting. When teeth are missing, the alveolar bone, or the portion of the jawbone that anchors the teeth in the mouth, no longer receives the necessary stimulation and begins to break down, or resorb. The body no longer uses or “needs” the jawbone, so it deteriorates and goes away.

The rate at which the bone deteriorates, as well as the amount of bone loss that occurs, varies greatly among individuals. However, most loss occurs within the first eighteen months following the extraction and will continue gradually throughout your life.

Periodontal Disease

Periodontal diseases are ongoing infections of the gums that gradually destroy the support of your natural teeth. Periodontal disease affects one or more of the periodontal tissues: alveolar bone, periodontal ligament, cementum, or gingiva. While there are many diseases that affect the tooth-supporting structures, plaque-induced inflammatory lesions make up most periodontal issues and are divided into two categories: gingivitis and periodontitis. While gingivitis, the less serious disease, may never progress into periodontitis, it always precedes periodontitis.

Dental plaque is the primary cause of gingivitis in genetically susceptible individuals. Plaque is a sticky, colorless film composed primarily of food particles and various types of bacteria that adheres to your teeth at and below the gum line. Plaque constantly forms on your teeth, even minutes after cleaning. Bacteria found in plague produce toxins, or poisons, that irritate the gums. Gums may become inflamed, red, swollen, and bleed easily. If this irritation is prolonged, the gums will separate from the teeth, causing pockets (spaces) to form. If daily brushing and flossing is neglected, plaque can harden into a rough, porous substance known as calculus (or tartar). This can occur both above and below the gum line.

Periodontitis is affected by bacteria that adhere to the tooth’s surface, along with an overly aggressive immune response to these bacteria. If gingivitis progresses into periodontitis, the supporting gum tissue and bone that hold teeth in place deteriorate. The progressive loss of this bone, the alveolar, can lead to the loosening and subsequent loss of teeth.

Dentures/Bridgework

Unanchored dentures are placed on top of the gum line, but they do not provide any direct stimulation to the underlying alveolar bone. Over time, the lack of stimulation causes the bone to resorb and deteriorate. Because this type of denture relies on the bone to hold them in place, people often experience loosening of their dentures and problems eating and speaking. Eventually, bone loss may become so severe that dentures cannot be held in place with strong adhesives, and a new set of dentures may be required. Proper denture care, repair, and refitting are essential to maintaining oral health.

Some dentures are supported by anchors, which do help adequately stimulate and therefore preserve bone.

With bridgework, the teeth on either side of the appliance provide sufficient stimulation to the bone, but the portion of the bridge that spans the gap where the teeth are missing receives no direct stimulation. Bone loss can occur in this area.

By completing a bone graft procedure, Dr. Galante is now able to restore bone function and growth, thereby halting the effects of poor denture care.

Facial Trauma

When a tooth is knocked out or broken to the extent that no biting surface is left below the gum line, bone stimulation stops, which results in jawbone loss. Some common forms of tooth and jaw trauma include teeth knocked out from injury or accident, jaw fractures, or teeth with a history of trauma that may die and lead to bone loss years after the initial trauma.

A bone grafting procedure would be necessary to reverse the effects of bone deterioration, restoring function and promoting new bone growth in traumatized areas.

Misalignment

Misalignment issues can create a situation in the mouth where some teeth no longer have an opposing tooth structure. The unopposed tooth can over-erupt, causing deterioration of the underlying bone.

Issues such as TMJ problems, normal wear-and-tear, and lack of treatment can also create abnormal physical forces that interfere with the teeth’s ability to grind and chew properly. Over time, bone deterioration can occur when the bone is losing stimulation.

Osteomyelitis

Osteomyelitis is a type of bacterial infection in the bone and bone marrow of the jaw. This infection leads to inflammation, which can cause a reduction of blood supply to the bone. Treatment for osteomyelitis generally requires antibiotics and the removal of the affected bone. A bone graft procedure may be required to restore bone function and growth lost during removal.

Sinus Deficiencies

When molars are removed from the upper jaw, the part of the jawbone supporting the molar’s roots is no longer needed, and over time resorbs or decreases in size. This often results in inadequate bone volume into which an implant can be placed. Performing a “sinus lift” can restore the support bone necessary to secure an implant, which in turn supports the replacement tooth.

This condition usually develops over several years and may result in insufficient bones from the placement of dental implants. Dr. Galante can perform a procedure called a “sinus lift” that can treat enlarged sinuses.