Most common cause of oroantral fistula ?

Ans. is 'c' i.e., Tooth extraction Oroantral fistula It is communication between the antrum and oral cavity. Etiology Dental extraction :- Most impoant cause and maxillary first molar accounts for 50% of oral-antral fistulas caused by extractions. Maxillary second and third molar extractions account for other 50%. Infection :- TB, syphilis, leprosy of maxillary bone. Malignant neoplasm :- Causes erosion of antrum. Fracture or penetrating injuries of maxilla. Midline granuloma (a form of lymphoma) Failure of sublabial incision to heal after Caldwell - Luc operation. Clinical features Regurgitation of food Discharge (often foul smelling) Inability to built positive or negative pressure in mouth.