What is the most common anatomical site for medication-related osteonecrosis of the jaw (MRONJ)?

The posterior mandible (molar/premolar region) is the most common site for medication-related osteonecrosis of the jaw (MRONJ), occurring in approximately 65–73% of cases. The mandible overall accounts for about 60–70% of MRONJ cases versus 30% in the maxilla. The posterior mandible's predilection may relate to: denser cortical bone with less collateral blood supply than the maxilla, greater occlusal stress concentrations, higher rates of tooth extraction in this region, and reduced periosteal vascularity. The maxilla (especially posterior) is the second most common site. Risk factors include bisphosphonates, denosumab, invasive dental procedures (extractions), and poor oral hygiene.