Osseous changes in patients with medication-related osteonecrosis of the jaws

Abstract

Objectives: Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect of antiresorptive agents. The aim of this study was to investigate the osseous changes in patients with MRONJ.

Methods: Cone beam CT (CBCT) images of 25 patients with MRONJ and controls were retrospectively evaluated. Buccal, lingual, apical cortical bone thicknesses; buccal, lingual, apical intracortical and cancellous bone density; diameter of mental foramen and incisive canal, and width of mental foramen were measured.

Results: Buccal and apical cortical bone thicknesses were increased; however intracortical radiodensity values decreased in the Study Group when compared with the Control Group (p = 0.007, p = 0.001). Narrowing of incisive canal was observed in patients with MRONJ (p = 0.000).

Conclusions: Clinician should have awareness about narrowing of incisive canal, apical and buccal cortical bone thickening, decreasing in cancellous bone radiodensity, and the lingual cortex destruction in patients with MRONJ.

hosphonates (Bps) are inorganic pyrophosphates effective in inhibiting bone resorption and most widely prescribed for the treatment of patients with osteoporosis, Paget’s Disease, hypercalcemia related to malignancy, multiple myeloma and symptomatic fibrous dysplasia.1,2 Osteonecrosis of the jaw is a potentially severe side effect of antiresorptive agents including bisphosphonates with a mean incidence of 7% (0 to 27.5%) in patients treated intravenously.3 The American Association of Oral and Maxillofacial Surgeons (AAOMS) has updated their definition in 2014 as medication-related osteonecrosis of the jaw (MRONJ) to (1) current or previous treatment with antiresorptive or antiangiogenic agents; (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region that has persisted for more than 8 weeks and (3) no history of radiation therapy to the jaws or obvious metastatic disease to the jaws.4 Accurate staging is essential to plan the correct treatment for MRONJ patients. Staging of MRONJ is currently based on the classification proposed by Ruggiero and colleagues5 and has been adopted by AAOMS6 (Table 1). Although clinical examination is favoured for diagnosis of MRONJ primarily, imaging is essential for determining the extent of lesion, diagnosing early stages and excluding fractures.7 Conventional radiography and CT scans have been widely used and may show osseous changes such as periosteal reaction, sclerotic lesions, lucency and sequester formations; however, there is no golden standard.8,9 There are few reports for the quantitative evaluation10,11 of osseous changes by using cone beam CT (CBCT) and no distinct clinical-radiological systematization of MRONJ. Diagnosis of MRONJ in CBCT is usually based on classical subjective image parameters. Therefore, the aim of this study was to investigate the differences in radiological variables between the patients with MRONJ and healthy individuals in CBCT.