Reasons for Jaw Bone Loss

What causes jaw bone deterioration?

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

How do dental extractions affect jaw bone?

When an adult tooth is removed and not replaced, jaw bone deterioration may occur. 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 in the mouth, no longer receives the necessary stimulation, and begins to break down, or resorb. The body no longer uses or “needs” the jaw bone, so it deteriorates and goes away.

The rate 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 continues throughout life.

What effect does periodontal disease have on jaw bone?

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 which affect the tooth-supporting structures, plaque-induced inflammatory lesions make up the majority of periodontal issues, and are divided into two categories: gingivitis and periodontitis. While gingivitis, the less serious of the diseases, 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 caused by bacteria that adhere to the tooth’s surface, as well as reside in the adjacent gums.  These bacteria release harmful toxins and cause an immune response.  If gingivitis progresses into periodontitis, the supporting gum tissue and bone that hold teeth in place deteriorates. The progressive loss of this bone can lead to loosening and subsequent loss of teeth.

Do dentures preserve jaw bone?

Unanchored dentures are placed on top of the gum line and, therefore, do not provide any positive stimulation to the underlying alveolar bone.  In fact, over time, pressure from the overlying denture 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 even with strong adhesives, and a new set may be required. Proper denture care, repair, and refitting are essential to maintaining oral health.

Some partial dentures are supported by anchors, but even these don’t 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. Sobhani is now able to restore bone function and growth, thereby halting the effects of poor denture care.

What about missing teeth?

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 jaw bone 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 misalignment and an altered bite.

What effect does osteomyelitis have on jaw bone?

Osteomyelitis is a type of bacterial infection in the jaw bone. The infection leads to some degree of bone death or necrosis. Treatment for osteomyelitis generally requires antibiotics and removal of the affected bone. A bone graft procedure may then be required to restore bone function and growth lost during removal.

Tumors:

Benign facial tumors, though generally non-threateningly, may grow large, invading more and more bone volume.  Malignant mouth tumors also 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. Grafting in patients with malignant tumors may be more challenging because treatment of the cancerous tumor generally requires removal of surrounding soft tissue as well.

What about developmental deformities?

Some conditions or syndromes known as birth defects are characterized by missing portions of the teeth, facial bones, jaw or skull.  Bone grafting procedures are performed to restore bone function and growth where it may be absent.

How do sinus deficiencies affect jaw bone health?

When molars are removed from the upper jaw, air pressure from the air cavity in the maxilla (maxillary sinus), causes resorption of the bone that formerly supported the teeth. As a result, the sinuses become enlarged, a condition called pneumatization.  This condition usually develops over years, and may result in insufficient bone for the placement of dental implants. Dr. Sobhani may recommend performance of a procedure called a “sinus lift” that can regenerate bone on the floor of these enlarged sinuses.