Necrosis is the death of tissue in the body, affecting various organs and bones. When this process occurs in the jawbone, it is known as osteonecrosis of the jaw (ONJ). This serious condition involves the deterioration of jawbone tissue, and this article aims to provide a clear understanding for the general public.
Defining Jaw Necrosis
Osteonecrosis of the jaw is characterized by the death of bone cells in the jawbone. This leads to the exposure of underlying bone through the gums, which fails to heal over an extended period, typically more than eight weeks. The exposed bone can occur in either the upper jaw (maxilla) or the lower jaw (mandible). ONJ specifically involves a lack of blood supply to a portion of the bone, causing the tissue to die.
The affected area of the jawbone may resemble broken teeth. This exposed bone is often susceptible to infection, further complicating the condition. While it can sometimes occur without an obvious cause, it frequently follows dental procedures where the bone is exposed and does not properly recover.
Key Causes and Risk Factors
A primary cause of jaw necrosis is medication-related osteonecrosis of the jaw (MRONJ), often linked to specific bone-strengthening medications. Bisphosphonates, including alendronate, risedronate, ibandronate, and zoledronic acid, are commonly implicated. Denosumab is also a medication that can contribute to MRONJ.
These medications treat conditions like osteoporosis and cancers that have spread to the bone. Patients receiving high intravenous doses for cancer treatment face a higher risk than those taking lower oral doses for osteoporosis. The longer these medications are taken, the higher the likelihood of developing MRONJ.
Another significant cause is osteoradionecrosis (ORN), resulting from radiation therapy to the head and neck, typically for cancer treatment. Radiation can damage the bone and its blood supply, making it vulnerable to necrosis, particularly in the lower jaw due to its limited blood flow. The risk of ORN increases with higher radiation doses and if the patient also undergoes chemotherapy.
Other contributing factors include localized trauma, such as tooth extractions that do not heal properly. Infections in the jaw, underlying systemic diseases like diabetes, and poor oral hygiene can also increase the risk.
Recognizing the Symptoms
Individuals experiencing jaw necrosis may notice various signs. Pain in the jaw or teeth is a common complaint, though some people may have no pain initially. Swelling in the jaw and surrounding gum tissues can also occur, sometimes accompanied by a discharge of pus.
A distinct symptom is the visible exposure of bone in the mouth that does not heal. This exposed bone can feel rough or sharp, potentially causing sores on the tongue or other soft tissues. Loose teeth in the affected area are another indicator. Some individuals may experience numbness, a tingling sensation, or a feeling of heaviness in the jaw or lower lip, which suggests nerve involvement.
Difficulty with speaking or eating can arise as the condition progresses. Bad breath may also be present, especially if there is an infection.
Diagnosis and Management
Diagnosing jaw necrosis typically involves a thorough clinical examination by a dental professional or oral surgeon. They will visually inspect the mouth for exposed bone and assess any associated signs like swelling, redness, or pus. A history of medications, especially bisphosphonates or denosumab, and any previous radiation therapy to the head and neck, is important for diagnosis.
Imaging techniques are also used to determine the extent of bone involvement. X-rays can show changes in bone structure, while more advanced imaging like CT scans or cone-beam CT (CBCT) provides a detailed three-dimensional view of the jawbone. These images help confirm the diagnosis and guide treatment planning.
Management of jaw necrosis often begins with conservative approaches aimed at alleviating symptoms and preventing further progression. This can include pain control medications, antibiotics to manage infection, and antiseptic mouth rinses to maintain oral hygiene. Gently debriding the exposed bone may also be performed.
Surgical intervention may be considered for more advanced cases or when conservative treatments are not effective. This involves removing the dead bone and any affected teeth. However, surgery is often approached cautiously to avoid exacerbating the condition. Management is tailored to each individual, considering the severity, overall health, and medical history.
Preventive Measures
Preventing jaw necrosis involves a proactive approach to oral health. Maintaining good oral hygiene through regular brushing and flossing is important. This helps reduce the presence of bacteria in the mouth and promotes gum health.
Regular dental check-ups are important, allowing dentists to identify and address any dental issues early on. For individuals about to start medications like bisphosphonates or denosumab, a comprehensive dental evaluation should be completed before treatment begins. This allows for any necessary dental procedures, like tooth extractions, to be performed and healed prior to starting the medication.
Open communication between patients and their healthcare providers is important. Patients should inform all their doctors about any medications they are taking or treatments they are undergoing, especially those that can affect bone health. This collaborative approach helps ensure dental care is coordinated with overall medical treatment, reducing the risk of jaw necrosis.