Medication-related Osteonecrosis of the Jaw: A Review

Abstract

Medication-related osteonecrosis of the jaw (MRONJ) is a rare, severe debilitating condition from unknown causes. It is characterized by nonhealing exposed bone in a patient with a history of antiresorptive or antiangiogenic agents in the absence of radiation exposure to the head and neck region. The first case of MRONJ was reported in the early 2000s. Diagnostic criteria for MRONJ was developed by the American Association of Oral and Maxillofacial Surgeons (AAOMS) based on pharmacological history as well as clinical and radiographic features. Antiresorptive medications such as bisphosphonate and denosumab are currently considered the treatment of choice in patients with osteoclastic bone disease. These reduce bone turnover and improve bone density, thereby improving bone quality. These agents have also been shown to reduce the risk of osteoporotic fractures due to their potent effect in suppressing osteoclastic activity by slowing the remodeling process and increasing bone density, thereby improving quality of life for most of the patients. Despite the great benefits of bisphosphonates and other antiresorptive medications, osteonecrosis of the jaw (ONJ) due to the effects of these medications in the presence of a local risk factor is a significant drawback. Moreover, antiangiogenic drugs play a major role in developing bone necrosis. They are prescribed in cancer cases to prevent metastasis through the blood and lymph nodes. These drugs interfere with the formation of new blood vessels, resulting in ischemia and eventually ONJ. This risk can be managed by evaluating the route and the duration of administration as such a risk can be considered dose-time dependent. As a preventive measure, dental screening before initiating any type of ONJ-related medications can significantly lower the risk of ONJ. Treatment goals can be achieved through pain and infection control, in addition to the management of bone necrosis and resorption. The aim of this review is to identify all causative agents and summarize the preventive measures, diagnostic criteria, and treatment strategies related to MRONJ.

Keywords: bisphosphonates; bronj; denosumab; necrosis.

Figure 1. The appearance of ONJ on panoramic radiograph

Panoramic radiograph view of ONJ shows alveolar bone reaction at the area of the empty socket of previously extracted teeth (arrowhead and white arrow), and loss of cortication on the right side compared to the left (black arrows) *Sclerosis ONJ: osteonecrosis of the jaw

Figure 2. The appearance of ONJ on MRI modality: T1-weighted image

The image shows reduced signal intensity in the right mandibular ramus (white arrow) ONJ: osteonecrosis of the jaw; MRI: magnetic resonance imaging

Figure 3. The appearance of ONJ on MRI modality: T2-weighted image

Tissue window with increased signal intensity in the adjacent soft tissues of the right mandible (white arrow) ONJ: osteonecrosis of the jaw; MRI: magnetic resonance imaging

Figure 4. SPECT bone scintigraphy

SPECT bone scintigraphy shows increased uptake in the right mandible (black arrows) SPECT: single-photon emission tomography