Peri‐Implant‐Medication‐Related Osteonecrosis of the Jaws: Epidemiological, Clinical and Radiographic Features—A Retrospective Cohort Study

Aim To characterize peri‐implant‐medication‐related osteonecrosis of the jaw (PI‐MRONJ) (epidemiological, clinical, and radiographic features) in order to optimise its diagnosis and management. Materials and Methods This is a retrospective cohort study including patients diagnosed with MRONJ that developed spontaneously around previously osseointegrated and loaded dental implants. Data were extracted from medical records. Outcome parameters included the underlying health condition, onset time, age, distinct radiographic features using 3D imaging, severe complications and systemic comorbidities. Patients were categorised into oncologic or osteoporotic groups. Results Forty patients (86 implants) were diagnosed with PI‐MRONJ between 2015 and 2024. The mean age was 72.1. Radiographic features distinct from peri‐implantitis included—osteolysis (80%), the most prevalent radiographic feature, osteosclerosis (57.1%), sequestration (54.3%), periosteal reaction and inferior alveolar canal involvement (30.8% each) and maxillary sinus involvement (77.8% of maxillary cases). A delay in diagnosis (only two cases [5%] were diagnosed at stage 1) was confirmed. Consequently, severe complication rates were high (38.7% for mandible and 55.6% for maxilla). Patients had an average of 3.1 systemic comorbidities. Oncologic patients showed a shorter onset time from antiresorptive treatment to diagnosis (mean 2.8 vs. 6.2 years, p < 0.001). Conclusions PI‐MRONJ may clinically and radiographically resemble peri‐implantitis. However, it appears to represent a distinct and underrecognised subtype of MRONJ. Consequently, a delay in diagnosis occurs (stage 3). The advanced diagnostic stage aggravates a high rate of severe complications. A diagnostic flowchart is proposed to aid in differential diagnosis. Advanced age (> 70 years) and distinct radiographic features are suggested as hallmark features.