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 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.

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 which affect the tooth-supporting structures, plaque-induced inflammatory lesions make up the majority of periodontal issues. 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. When gingivitis progresses to periodontitis, the supporting gum tissue and bone that holds teeth in place deteriorates. The progressive loss of this bone can lead to loosening and subsequent loss of teeth.

Dentures/Bridgework

Unanchored dentures are placed on top of the gum line, and therefore 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 even with strong adhesives, and a new set 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.

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 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.

Misalignment of Teeth

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 where bone is losing stimulation.

Pathology

Some conditions, syndromes, or birth defects are characterized by missing portions of the teeth, facial bones, jaw or skull. Additionally, removal of some benign growths in the gums and/or jaws may result in removal of a large portion of bone.

Sinus Deficiencies

When molars are removed from the upper jaw, resorption of the bone that formerly held the teeth in place occurs. As a result, the sinuses become enlarged. This condition usually develops anywhere from three months to several years, and may result in insufficient bone for the placement of dental implants.