Circuit 4, station 10

Medication-related Osteonecrosis of the Jaw: A Review
Definition:
Osteonecrosis of the jaw (ONJ) is a rare but serious condition characterised by the death of bone tissue in the jaw.
ONJ is also known as bisphosphonate-related osteonecrosis of the jaw (BRONJ) because it is most commonly associated with the use of bisphosphonate medications, which are commonly used to treat osteoporosis and cancer-related bone disease.
The diagnosis of ONJ is typically made based on clinical presentation and radiographic findings, such as an area of exposed bone in the jaw. Dental x-rays and CT scans may be used to confirm the diagnosis and assess the extent of the bone necrosis.

Clinical symptoms and signs:
Symptoms of ONJ can include pain, swelling, and drainage from the affected area, as well as the loosening of teeth or difficulty with chewing or speaking. In some cases, individuals with ONJ may not experience any symptoms until the condition has progressed.
ONJ can be difficult to diagnose, and healthcare professionals should be aware of the potential risk factors and perform a thorough evaluation of any individuals who may be at increased risk.

Staging of disease:
ONJ is typically classified into one of four stages based on the extent of bone involvement and the severity of symptoms.
• Stage 0 refers to the presence of non-specific symptoms, such as pain or infection, without any clinical or radiographic evidence of bone necrosis.
• Stage 1 involves the presence of exposed bone or fistulae that do not cause any symptoms.
• Stage 2 involves the presence of exposed bone or fistulae with pain or other symptoms.
• Stage 3 involves the presence of exposed bone or fistulae with severe pain and infection, as well as the presence of fracture, extraoral fistula, or involvement of the adjacent soft tissues.
Brief summary of bisphosphonate causation:
Bisphosphonates are a class of medications that are commonly used to treat osteoporosis and cancer-related bone disease by inhibiting the activity of cells that break down bone tissue.
Bisphosphonates work by inhibiting the activity of cells called osteoclasts, which are responsible for breaking down and remodelling bone tissue. However, in some cases, this inhibition can lead to a decrease in bone turnover and blood supply, which can result in the development of osteonecrosis.
In addition to medication use, several other risk factors may increase the risk of developing ONJ. These include dental procedures such as extractions and implants, poor oral hygiene, and smoking. Certain medical conditions such as cancer, diabetes, and autoimmune diseases may also increase the risk of developing ONJ.

List of other drugs that can cause ONJ:
Bisphosphonates are considered the primary causative factor in the development of ONJ. Several drugs have also been linked to an increased risk of developing ONJ. These include:
• Angiogenesis inhibitors, such as bevacizumab and sunitinib, used in the treatment of cancer
• Denosumab, a monoclonal antibody used to treat osteoporosis and bone metastases in cancer patients
• Anti-RANKL agents, such as denosumab and Prolia, used in the treatment of osteoporosis and bone metastases in cancer patients
• Corticosteroids, used to treat a variety of conditions including autoimmune diseases, asthma, and allergies.

Management options:
The management of ONJ typically involves a combination of conservative measures, including pain management, antibiotics, and oral hygiene, as well as surgical interventions as needed.
In some cases, hyperbaric oxygen therapy may also be beneficial in promoting the healing of the affected bone. The goal of treatment is to manage symptoms and prevent further bone loss or exposure. In addition to treatment, individuals with ONJ may also benefit from supportive care, such as nutritional support and physical therapy.
The prognosis for individuals with ONJ varies depending on the severity of the condition and the individual’s overall health status. In some cases, ONJ may resolve with conservative measures, while in others, ongoing management may be necessary to prevent further complications. Long-term follow-up is essential to monitor for recurrence of the condition and assess the effectiveness of treatment.
Overall, ONJ is a complex condition that requires careful evaluation and management by healthcare professionals. While the exact mechanism of ONJ development is not well understood, it is thought to be related to the use of certain medications and other risk factors. Treatment should be tailored to the individual’s specific needs and may involve a combination of conservative measures and surgical interventions. Ongoing monitoring and follow-up are essential to ensure that the condition is managed effectively and prevent further complications.