Osteomyelitis of the Jaw in a Pediatric Patient During Sequential Antiresorptive Therapy: A Case Report.

Medication-related osteonecrosis of the jaw (MRONJ) is a known complication of antiresorptive therapy, but it is rarely reported in pediatric patients. We present a 10-year-old girl with familial multicentric carpotarsal osteolysis (MCTO) associated with an MAFB mutation, who was referred for incidental radiographic abnormalities detected during orthodontic evaluation. The patient had received prolonged and sequential antiresorptive therapy, including alendronate, denosumab, and subsequent intravenous pamidronate and zoledronate. Imaging revealed diffuse periradicular sclerosis and irregular cortical resorption of the right mandibular ramus and coronoid process with periosteal reaction and suspected sequestration, raising concern for osteonecrotic change. Clinically, the patient was asymptomatic, with no exposed bone or signs of infection, and did not meet the diagnostic criteria for MRONJ. The lesion was therefore considered a possible subclinical manifestation associated with antiresorptive therapy. This case highlights that radiographic abnormalities may precede clinical MRONJ in high-risk pediatric patients, supporting the need for careful surveillance and conservative management.