Metachronous sites of osteonecrosis of jaw (ONJ) in all four quadrants of maxilla bones and mandible: a case report

Osteonecrosis of Jaw (ONJ) after treatment including Bisphosphonates (BP) is often multifocal, involving several sites of maxilla and/or mandible, in the same time (synchronous) or in different times (metachronous). The researchers report the case of metachronous involvement of all four jaw quadrants, after zoledronic acid treatment of breast cancer with bone metastases. At age of 72, on November 2010, a female patient received surgery for breast cancer. On October 2011, a diagnosis of ONJ was made at left hemi-mandible, with CT lesion and bone scan uptake; a spontaneous sequestrum expulsion was referred by the patient. History of ONJ in a patient treated with BPs makes automatically the patient at risk of other ONJ sites; short-term follow-up examination is needed during following months and years, whether BP treatment is resumed or not, to avoid diagnosis delay of new ONJ sites and possible complications. Careful evaluation of routine bone scans (Tc99 scintigraphy) can anticipate symptoms and clinical signs from new ONJ sites.