Foreign body–associated maxillary sinus aspergillosis caused by Endomethasone extrusion: diagnostic challenges, biological mechanisms, and surgical management

Abstract

Extrusion of endodontic sealers into the maxillary sinus is an uncommon but clinically significant complication, particularly when biologically active zinc oxide–eugenol–based materials are involved. Their persistence within the sinus may impair mucociliary clearance and sustain chronic inflammation. This report describes a 25-year-old woman with persistent unilateral maxillary pain following root canal treatment and subsequent extraction of the involved tooth. Cone-beam computed tomography revealed a well-defined radiopaque foreign body within the maxillary sinus associated with mucosal thickening. Conservative therapy failed to relieve symptoms, and surgical removal was performed using a Caldwell–Luc approach. Histopathological examination demonstrated septate fungal hyphae with acute-angle branching consistent with Aspergillus species in association with a foreign body reaction and chronic inflammatory changes. Complete symptom resolution was achieved and maintained at one-year follow-up. This case highlights the diagnostic value of CBCT in post-treatment persistent pain, the biological behaviour of extruded Endomethasone within the sinus, and the need for early surgical intervention in symptomatic patients. Preventive strategies based on preoperative anatomical assessment and controlled obturation are also discussed. This case defines a transition from odontogenic to biomaterial-induced sinonasal disease and proposes CBCT-based criteria for early surgical intervention.