Osteonecrosis of the jaw (ONJ) is a serious complication of both radiation and antiresorptive therapies. This study aimed to determine how many patients have been treated for medication-related osteonecrosis of the jaws (MRONJ) and osteoradionecrosis (ORN), and whether the number of diagnoses has decreased over time with improved awareness and preventative measures.
Medical records at the Royal Brisbane and Women's Hospital, Gold Coast University Hospital and Robina Hospital were reviewed to identify patients diagnosed with MRONJ and ORN between January 2003 and May 2017. Data on patient demographics, year of admission and primary disease were analysed.
Two hundred and thirty-eight patients were diagnosed with ONJ, of which 74.4% were ORN and 25.6% were MRONJ. Tongue (24.6%), floor of mouth (17.3%) and tonsillar (15.1%) squamous cell carcinomas were the most common primary diseases associated with ORN, with a strong male predominance (80%). Of patients diagnosed with MRONJ, 52.5% were taking low-dose antiresorptives for osteoporosis (44.2%), rheumatoid arthritis (4.6%) or Paget's disease (3.3%), while 47.5% were oncology patients receiving high-dose antiresorptives.
The number of patients diagnosed with MRONJ and ORN has trended upwards since 2003. ORN affected three times more patients than MRONJ, and patients on low-dose antiresorptives accounted for over half of the MRONJ cases.