Imaging findings in bisphosphonate-induced osteonecrosis of the jaws

Background. Bisphosphonates are drugs used in the treatment of lytic bone metastases, multiple myeloma, hypercalcemia of malignant origin, osteoporosis, and diseases such as Paget's disease. Recently osteonecrosis of the jaw has been associated with the use of bisphosphonates. This study describes the imaging findings of bisphosphonate-associated osteonecrosis of the jaws. Patients and methods. Eleven patients, receiving bisphosphonate medication for approximately 28 months, with pain on affected side, nonhealing extraction sockets, purulent discharge and swelling in soft tissue were examined. Imaging consisted of non-contrast enhanced CT and contrast enhanced MRI. All patients underwent surgery of affected bone and histology confirmed osteonecrosis. Results. CT scan showed osteolytic and sclerotic lesions with cortical bone destruction in all patients. The osteonecrosis was identified as delimited focal lesions with reduction of the signal on T1- weighted imaging and T2- weighted imaging. All the patients had soft-tissue involvement with enhancement in orbicular, buccinator muscle of the mouth or masticator space and adenopathy in submandibular and jugular digastric chain. Conclusions. Bisphosphonate related osteonecrosis of the jaw presents a variety of imaging findings that help to determine the extent of the disease and track the progression, however they are not specific for this disease.