A Case of Actinomycotic Osteomyelitis in Maxilla Presenting as Oroantral Fistula - A Rare Case Report.

RATIONALE: Actinomycotic osteomyelitis of the maxilla is a rare, chronic infection caused by Actinomyces species. Owing to the rich vascularity of the maxilla, involvement is uncommon, often leading to delayed diagnosis and increased morbidity if untreated. PATIENT CONCERNS: A patient presented with a 6-month history of dull, persistent maxillary pain following the extraction of right upper first premolar. DIAGNOSIS: Clinical examination revealed an oroantral fistula with an exposed, mobile sequestrum. Sequestrectomy with histopathological evaluation confirmed actinomycotic osteomyelitis. TREATMENT: Sequestrectomy with thorough debridement and intranasal antrostomy was performed for adequate sinus drainage. Prolonged high-dose intravenous antibiotics were administered, followed by oral therapy targeting Actinomyces. OUTCOMES: At 1-year follow-up, the patient was asymptomatic with no evidence of recurrence. TAKE-AWAY LESSONS: It is rare and often difficult to diagnose due to non-specific symptoms and negative cultures. Early suspicion, histopathological confirmation and individualised regimens considering patient compliance and access to care, plus long-term follow-up, ensure favourable outcomes.