Radiographic Evaluation of Medication-Related Osteonecrosis of the Jaw (MRONJ) With Different Primary Cancers and Medication Therapies

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a condition that affects the jaws and is characterized by exposed bone in the oral cavity that persists for more than eight weeks despite treatment. Additional criteria include that the patient should have a current or past history of antiresorptive drugs and/or in combination with antiangiogenic drugs, absence of metastasis, and no previous radiotherapy to the affected area. The radiographic features of MRONJ in most instances do not have any specific radiographic features. This is because standard radiographs usually show no stark abnormalities in the early stages of the disease. Objective: The study aimed to evaluate if any specific radiographic patterns are associated with primary cancers and between medications. Materials and methods: The study is an observational case series. A total of 50 cases of possible osteonecrosis from June 2010 to June 2013 archives of the Department of Oral and Maxillofacial Radiology were assessed. Based on the history, 12 cases that had a history of medication use that could lead to medication-related osteonecrosis of the jaw (MRONJ) were selected. Cone beam computed tomography (CBCT) scans of these 12 cases were evaluated using the CBCT reconstruction program InVivo Dental version 6 (Anatomage Inc., San Jose, CA, USA). The number of areas showing sequestration, the pattern of osteonecrosis, and the extent were assessed. Primary cancer and the type of medication were also assessed to identify if certain cancers or drugs showed any distinctive pattern of osteonecrosis. Reconstructed panoramic images and true three-dimensional (3D) multi-planar images were assessed to study the condition. An oral and maxillofacial radiology resident in training and a board-certified oral and maxillofacial radiologist assessed the images. Results: Radiographic findings varied among the 12 cases and included generalized sclerosis, osteosclerosis with widened periodontal ligament (PDL) space, bony sequestra, and bony necrosis. However, no specific or distinctive radiographic patterns were observed in any of the cases, regardless of the type of primary cancer or medication used. Conclusion: It is challenging to radiographically distinguish between MRONJ cases with different primary cancer and/or medication. Future directions: Future studies should include evaluating larger samples with varying primary cancers and medications and combination drug therapies. Cases in an advanced stage of MRONJ do not have distinctive features due to extensive destruction and superimposed infection; it may be valuable to evaluate patients in the early stages of MRONJ to better understand distinguishing radiographic patterns specific to certain primary cancers or medications.