Osteonecrosis of the jaws (ONJ) in osteoporosis patients has been defined as rare, but the number of reported cases is increasing. We report a case of delayed ONJ diagnosis in a patient, who was being treated with alendronate, developing bone alterations both in maxilla and in mandible. Underestimation of ONJ incidence and missed or delayed ONJ diagnosis in osteoporosis patients might derive from lack of awareness of health providers as well as from an ONJ definition that is too restricted. The more recent definition of medication-related osteonecrosis of the jaws (MRONJ) released in 2014 by the American Association of Oral Maxillofacial Surgeons (AAOMS) accept fistula, besides bone exposure, as a major sign of disease, but it seems to be insufficient since it excludes all cases of ONJ disease without bone exposure. A new MRONJ definition is needed to avoid missing or delayed diagnosis.
Keywords: BRONJ; MRONJ; alendronate; bisphosphonate; laser therapy; osteonecrosis of jaw; osteoporosis.