No abstract

No abstract

Management of osteonecrosis of the jaw associated with antiresorptive agents is challenging, and outcomes are unpredictable. The severity of disease is the main guide to management, and can help to predict prognosis. Most available staging systems for osteonecrosis, including the widely-used American Association of Oral and Maxillofacial Surgeons (AAOMS) system, classify severity on the basis of clinical and radiographic findings. However, clinical inspection and radiography are limited in their ability to identify the extent of necrotic bone disease compared with computed tomography (CT). We have organised a large multicentre retrospective study (known as MISSION) to investigate the agreement between the AAOMS staging system and the extent of osteonecrosis of the jaw (focal compared with diffuse involvement of bone) as detected on CT. We studied 799 patients with detailed clinical phenotyping who had CT images taken. Features of diffuse bone disease were identified on CT within all AAOMS stages (20%, 8%, 48%, and 24% of patients in stages 0, 1, 2, and 3, respectively). Of the patients classified as stage 0, 110/192 (57%) had diffuse disease on CT, and about 1 in 3 with CT evidence of diffuse bone disease was misclassified by the AAOMS system as having stages 0 and 1 osteonecrosis. In addition, more than a third of patients with AAOMS stage 2 (142/405, 35%) had focal bone disease on CT. We conclude that the AAOMS staging system does not correctly identify the extent of bony disease in patients with osteonecrosis of the jaw.

Recent data suggest that the traditional definition of bisphosphonate-associated osteonecrosis of the jaw (ONJ) may exclude patients who present with the non-exposed variant of the condition. To test the hypothesis that a proportion of patients with ONJ remain undiagnosed because their symptoms do not conform to the traditional case definition, we did a secondary analysis of data from MISSION (Multicentre study on phenotype, definition and classification of osteonecrosis of the jaws associated with bisphosphonates), a cross-sectional study of a large population of patients with bisphosphonate-associated ONJ who were recruited in 13 European centres. Patients with exposed and non-exposed ONJ were included. The main aim was to quantify the proportion of those who, according to the traditional case definition, would not be diagnosed with ONJ because they had no exposed necrotic bone. Data analysis included descriptive statistics, median regression, and Fisher's exact test. A total of 886 consecutive patients were recruited and 799 were studied after data cleaning (removal or correction of inaccurate data). Of these, 607 (76%) were diagnosed according to the traditional definition. Diagnosis in the remaining 192 (24%) could not be adjudicated, as they had several abnormal features relating to the jaws but no visible necrotic bone. The groups were similar for most of the phenotypic variables tested. To our knowledge this is the first study in a large population that shows that use of the traditional definition may result in one quarter of patients remaining undiagnosed. Those not considered to have ONJ had the non-exposed variant. These findings show the importance of adding this description to the traditional case definition.

No abstract