How to diagnose avascular necrosis (AVN) of the jaw?

From the Guidelines

Diagnosing vascular necrosis of the jaw requires a comprehensive approach that includes confirming the presence of exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region, a history of treatment with a bone-modifying agent or angiogenic inhibitor, and no history of radiation therapy to the jaws or metastatic disease to the jaws, as outlined in the MASCC/ISOO/ASCO clinical practice guideline 1. To diagnose vascular necrosis of the jaw, the following steps should be taken:

• A thorough medical history should be obtained, focusing on risk factors such as bisphosphonate use, radiation therapy, steroid treatment, or trauma.
• Physical examination should assess for exposed bone, pain, swelling, drainage, or pathologic fractures.
• Radiographic evaluation is essential, starting with panoramic X-rays to identify areas of bone sclerosis, osteolysis, or sequestration.
• Advanced imaging including CT scans provides detailed bone architecture assessment, while MRI can detect early marrow changes before radiographic evidence appears.
• Laboratory tests including complete blood count, inflammatory markers, and calcium levels can support the diagnosis.
• In uncertain cases, bone biopsy may be necessary to confirm the diagnosis and rule out malignancy or infection, revealing necrotic bone with empty lacunae and absence of osteocytes, as recommended by the Expert Panel in the MASCC/ISOO/ASCO clinical practice guideline 1. The diagnosis of vascular necrosis of the jaw should be based on the criteria outlined in the MASCC/ISOO/ASCO clinical practice guideline, which includes:
• Current or previous treatment with a bone-modifying agent or angiogenic inhibitor
• Exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks
• No history of radiation therapy to the jaws or metastatic disease to the jaws 1. Early diagnosis is crucial as avascular necrosis is progressive and can lead to significant morbidity if treatment is delayed, and a prompt referral to a dental specialist is warranted to confirm or rule out suspected MRONJ and the need for close follow up 1.

From the Research

Diagnosis of Vascular Necrosis of the Jaw

To diagnose vascular necrosis of the jaw, also known as osteonecrosis of the jaw (ONJ), the following methods can be used:

• Imaging techniques such as panoramic radiograph, computed tomography (CT), magnetic resonance imaging (MRI), bone scanning, and positron emission tomography (PET) can be used to assess the extent of ONJ 2, 3.
• CT scans have been shown to have a high detectability for ONJ lesions, with a detectability rate of 96% 3.
• MRI scans also have a high detectability rate, with a rate of 92% 3.
• Texture analysis of CT images can be used to quantitatively assess the mandibular bone marrow and detect stage 0 MRONJ 4.
• Clinical assessment and conservative dental management are also important for diagnosing and managing ONJ 5.

Risk Factors for ONJ

The following are risk factors for ONJ:

• Antiresorptive therapy with bisphosphonates or denosumab 2, 5, 6.
• Glucocorticoid use 2.
• Maxillary or mandibular bone surgery 2.
• Poor oral hygiene 2, 5, 6.
• Chronic inflammation 2.
• Diabetes mellitus 2.
• Ill-fitting dentures 2.
• Other drugs, including antiangiogenic agents 2.

Prevention and Management of ONJ

To prevent and manage ONJ:

• Elimination or stabilization of oral disease prior to initiation of antiresorptive agents is recommended 2.
• Maintenance of good oral hygiene is important 2, 5, 6.
• Conservative therapy, including topical antibiotic oral rinses and systemic antibiotic therapy, can be used to manage ONJ 2.
• Localized surgical debridement may be indicated in advanced nonresponsive disease 2.