Pulpal Disease Arising from Medication-related Osteonecrosis of the Jaw: A Case Report

Although bisphosphonates are widely used to treat conditions such as osteoporosis, they may cause osteonecrosis of the jaw. We treated a patient with no history of tooth extraction or other surgical treatment who developed medication-related osteonecrosis of the jaw (MRONJ) with secondary pulpal disease. A 79-year-old woman presented with purulent discharge from the gum at the incisor region. She had been using bisphosphonates for 9 years. Tooth #6 had undertaken root canal treatment at a general practice. All teeth other than tooth #6 reacted to electric pulp testing. Computed tomographic imaging revealed signs suggestive of necrotic bone, and MRONJ was diagnosed. Teeth #7 and #8, which had initially exhibited vital reactions, also subsequently ceased to react to thermal and electric pulp testing. Root canal treatment was performed on teeth #6-8, and their condition was monitored. Computed tomographic imaging at 9 months after the first presentation revealed that the bone defect had greatly enlarged with separation of the necrotic bone; therefore, excision of the necrotic bone and curettage were performed in the department of oral and maxillofacial surgery. The loss of pulp reaction in teeth that had exhibited a vital reaction at the first presentation was considered to indicate that teeth #6-8 had developed dental pulp pathosis as a result of MRONJ.