Medication-Related Osteonecrosis of the Jaw Subsequent to Peri-Implantitis: A Case Report and Literature Review.

The aim of this report was to document a rare case of medication-related osteonecrosis of the jaw (MRONJ) that developed around the already osseointegrated implants in the maxillary right molar region. A 73-year-old woman presented at our university dental hospital in May 2017 with a chief complaint of discomfort near a maxillary implant. Her first visit was in 2006, and the maintenance treatment began in 2007 after the periodontal treatment. During the implant maintenance period there were no complications; however, the patient began taking alendronate sodium hydrate (Fosamac tablets, 35 mg, once weekly), an oral bisphosphonate (BP) since 2013, for treatment of osteoporosis. Eight years after starting implant maintenance, in 2016, peri-implantitis occurred, for which mechanical cleaning and antimicrobial therapy were performed. Peri-implantitis symptoms disappeared, and the medical condition improved. Nonetheless, in 2017, MRONJ developed 4 years after she commenced taking the BP. The patient underwent implant removal and sequestrectomy. There was no postoperative recurrence. Since it was such a rare case, we performed a literature review but only discovered a few similar cases. Because various triggers may lead to the development of MRONJ, even if already osseointegrated implant, it is important to note that implants in patients taking BPs should be more carefully maintained.