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:
When an adult tooth is removed and not replaced, jawbone deterioration may occur. Natural teeth are embedded in the jawbone, and they stimulate the jawbone through activities such as chewing and biting. When teeth are missing, the bone no longer receives the stimulation it needs, and it often begins to break down. Because the body no longer uses or needs the jawbone, it deteriorates.
The rate of this deterioration can vary greatly among individuals. While most loss occurs within the first eighteen months following an extraction, it can continue throughout life.
Periodontal diseases are ongoing infections of the gums that gradually destroy the support of natural teeth. Periodontal disease affects one or more of the periodontal tissues: the alveolar bone, periodontal ligament, cementum, or gingiva. While many diseases can affect the tooth-supporting structures, plaque-induced inflammatory lesions cause the majority of periodontal problems and can be divided into two categories: gingivitis and periodontitis. Gingivitis is the less serious and may never progress into periodontitis, but it always precedes periodontitis.
In genetically susceptible individuals, dental plaque is the primary cause of gingivitis. Plaque is a sticky colorless film, composed primarily of food particles and various types of bacteria, which adheres to the teeth at and below the gum line. Plaque constantly forms on teeth, even minutes after cleaning. Bacteria found in plaque produce toxins or poisons that irritate the gums. Gums may become inflamed, red, and swollen; they may bleed easily. If this irritation is prolonged, the gums separate from the teeth causing pockets to form. If daily brushing and flossing is neglected, plaque can also harden into a rough, porous substance known as calculus (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 holds teeth in place deteriorates. The progressive loss of this bone can lead to loosening and subsequent loss of teeth.
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. The denture wearers then experience loosening of their dentures and problems eating and speaking. Eventually, bone loss may become so severe that even strong adhesives will fail to hold the dentures in place, and new dentures may be required. Proper denture care, repair, and refitting are essential to maintaining oral health.
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.
When a tooth is knocked out or broken to the extent that no biting surface is left below the gum line, bone stimulation stops. This often causes bone loss. 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 issues can create a situation where some teeth no longer have an opposing tooth structure. The unopposed tooth can overerupt, causing deterioration of the underlying bone. 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 result.
Osteomyelitis is a type of bacterial infection in the bone and bone marrow of the jaw. The infection leads to inflammation, which can cause a reduction of blood supply to the bone. 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.
Benign facial tumors, though generally non-threatening, may grow large and require removal of a portion of the jaw. Malignant mouth 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 jaw function. 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.
Some conditions or syndromes known as birth defects are characterized by missing portions of the teeth, facial bones, jaw, or skull. The MVOMS surgical team may be able to perform a bone-graft procedure to restore bone function and growth.
When molars are removed from the upper jaw, air pressure from the maxillary sinus can cause resorption of the bone that formerly held the teeth in place. As a result, the sinuses become enlarged or “hyper-neumatized. This condition usually develops over several years and may result in insufficient bone to enable placement of dental implants. One of the MVOMS surgeons can treat enlarged sinuses by performing a sinus-lift procedure.