Reasons for Jawbone Loss and Deterioration
The following are the most common causes for jawbone deterioration and loss of bone volume that would require a bone grafting procedure:
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 biting and chewing. When teeth are missing, the alveolar bone (the portion of the jawbone that anchors the teeth) no longer receives the necessary stimulation and begins to break down, or resorb. The body no longer uses or “needs” the jawbone to support the teeth which are now missing, so the jawbone deteriorates (resorbs).
The rate the bone deteriorates, as well as the amount of bone loss that occurs, varies greatly among individuals. In general, most of the bone loss occurs within the first eighteen months following tooth extraction, and then continues throughout life.
Periodontal disease is an ongoing infection of the gums that gradually destroys 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 which affect these tooth-supporting structures, plaque-induced inflammatory lesions are the major cause of periodontal disease, and are divided into two categories: gingivitis (inflammation of the gums) and periodontitis (inflammation of the alveolar bone resulting in loss of bone). While gingivitis (which is more superficial) 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 which adhere to your teeth at and below the gum line. Plaque constantly forms on your teeth, even minutes after cleaning. Bacteria found in plaque produce toxins or poisons that irritate the gums. Gums may become inflamed, red, swollen, and bleed easily. If this irritation is prolonged, the gums separate from the teeth causing pockets (spaces) to form. If daily brushing and flossing are neglected, plaque can also 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 surface of the teeth, along with an overly aggressive immune response to these bacteria. If gingivitis progresses into periodontitis, the supporting bone that anchors the teeth in place deteriorates. This progressive loss alveolar bone ultimately leads to loosening, and sometimes loss of teeth.
Unanchored dentures (dentures not attached to teeth or implants) are placed on top of the gum line, and therefore do not provide any direct stimulation to the underlying alveolar bone. Eventually this lack of stimulation causes the bone to resorb. Because these types of dentures rely on the bone to hold them in place, people often experience loosening of their dentures resulting in difficulty eating and speaking. The bone loss may become so severe that dentures cannot be held in place even with strong adhesives, and a new set may be required. Proper denture care, repair, and refitting are essential to maintaining oral health.
Dentures can be supported by dental implants, which do help to adequately stimulate and preserve bone.
With bridgework, the teeth on either side of the bridge (known as abutments) provide sufficient stimulation to the bone, however the portion of the bridge that spans the gap where the teeth are missing receives no direct stimulation. As a result, bone loss can occur in this area.
With bone grafting, Dr. Vecchione is now able to restore the lost bone volume and effectively reverse this process. If the bridge fails and implants are considered to be a logical alternative to replace the now missing teeth, bone grafting may be indicated.
When a tooth is knocked out or fractured to the extent that no biting or chewing surface is left, bone stimulation will stop, resulting in jaw bone loss. This may happen as a result of teeth being lost due to injury or accident, jaw fractures, or past trauma causing necrosis of the pulp (the tissue inside the tooth).
Sometimes there is a loss of significant alveolar bone when teeth are lost. This may be the result of a traumatic injury, and a reconstructive bone graft would be required in order to provide support for dental implants, or restore jawbone contour and/or support of overlying soft tissue.
When molars are removed from the upper jaw (maxilla), the usual amount of bone loss after tooth removal will occur. In addition, air pressure from the air cavity in the maxilla (maxillary sinus) may cause further resorption of this bone, from the maxillary sinus side. This is also bone which formerly supported the upper back teeth. As a result the sinuses become enlarged, or pneumatized. This condition usually develops over several years, and may result in insufficient bone for the placement of dental implants in the posterior maxilla (back part of the upper jaw). In this case Dr. Vecchione can perform a procedure called a sinus lift which can replace this lost bone in preparation for the placement of dental implants.
Misalignment can create a situation in the mouth where some teeth no longer have an opposing tooth. The unopposed tooth can over-erupt, causing deterioration of the underlying bone.
Issues such as lack of proper tooth contact (malocclusion) can also result in a lack of bone stimulation and subsequent loss of bone volume.
Osteomyelitis is a bacterial infection within the jawbone. The infection leads to inflammation which can cause necrosis of bone. Treatment of osteomyelitis includes removal of any necrotic bone, and this may result in a bone defect which may require a bone graft to replace bone lost as a result of the infection.
Benign jawbone tumors may grow quite large and require removal of a portion of the jaw. Malignant oro-facial and neck tumors almost always spread into the jaw, requiring removal of a section of the jaw. In both cases, reconstructive bone grafting is usually required to help restore function to the jaw. Reconstructive bone grafting after patients have had surgery for a malignant tumor is often more challenging due to the soft tissue loss associated with this type of surgery.
Some congenital syndromes or conditions are characterized by diminished or missing portions of the teeth, jaws, and/or other facial bones. A bone graft procedure may be required to replace this missing bone, often to create an adequate volume of bone into which dental implants can be placed.