Computerized tomographic findings in bisphosphonate-associated osteonecrosis of the jaw in patients with cancer

Objectives. To study bisphosphonate-associated osteonecrosis of the jaw with respect to radiographic, demographic, and clinical features. Study design. Thirty-two patients with painful exposed bone in the jaws subsequent to treatment with bisphosphonates for various neoplastic diseases were examined with both dental panoramic radiograph and multislice spiral computerized tomography (CT). Each case was assessed for the following radiologic signs: structural alteration of trabecular bone, cortical bone erosion, osteosclerosis, small sequestrum, extensive sequestrum, and presence of periosteal new bone. The McNemar, chi(2), and Kruskall-Wallis tests were performed to analyze the association between radiologic signs, demographic data, clinical aspects of the lesion, and type and duration of bisphosphonate therapy. Hierarchical cluster analysis was used to group patients into categories on the basis of CT signs and dental panoramic radiograph signs. The agreement between CT and dental panoramic radiograph clusters was analyzed by kappa index. Results. Dental panoramic radiograph proved positive for features of osteonecrosis in 18 cases and CT in 30. Computerized tomography was far superior to dental panoramic radiograph in detecting all the radiologic signs. The cluster analysis applied to CT signs showed a classification of the 32 patients in 4 categories characterized by an increasing number of signs coherent with the clinical extension of the lesions. Structural alteration of trabecular bone and cortical bone erosion, a constant finding in the 30 positive CTs, could be sometimes differentiated only with difficulty from those due to recent extraction. Dental panoramic radiograph missed the correct diagnosis of sequestration in 15 cases. Intense periosteal reaction was often found. The most extensive maxillary lesions were associated with new bone formation in Schneider mucous membrane, never described previously, and oroantral communications. Conclusions. Dental panoramic radiograph were found to be of limited use in assessing bisphosphonate-associated osteonecrosis of the jaw in patients for whom CT imaging was subsequently ordered.