Comparison of chronic osteomyelitis versus bisphosphonate-related osteonecrosis of the jaws in female patients without malignant bone disease

PurposeClinical findings of bisphosphonate-related osteonecrosis of the jaws (BRONJ) largely overlap with chronic osteomyelitis of the jaws (COMJ). This study analyzed the clinical and radiological differences between BRONJ and COMJ.Subjects and methodsThe clinical, radiological and scintigraphic findings of 60 female BRONJ patients were analyzed and compared to 37 female COMJ patients. Patients with cancer, metastatic bone disease, or a history of chemotherapy or radiotherapy were excluded from the study because of the potential effect on the radiographic findings.ResultsThe radiographic invasiveness of BRONJ at a local site was related to the advanced stages of BRONJ. A major clinical difference between BRONJ and COMJ was bone exposure (100% and 16%, respectively). BRONJ occurred at more multiple sites and showed a more osteolytic and invasive findings than that of COMJ (p < 0.05). The bone scintigraphic findings according to the radiographic findings of BRONJ and COMJ showed a similar pattern. Positive radioisotope uptake reflecting an increased osteoblastic activity pattern existed in most BRONJ (91.9%) and COMJ (94.6%) patients.ConclusionsThe essential clinical finding of BRONJ, bone exposure, might influence the pathophysiological condition of the bone and can explain the more advanced radiographic bone destruction and involvement of adjacent structures of BRONJ than that of COMJ. Increased radiotracer uptake in both COMJ and BRONJ lesions imply that BRONJ lesions are not ‘frozen’ and has a common finding of inflammatory response of a bone lesion.