Oroantral fistula

Oroantral fistula (OAF) is an abnormal condition of the face where the maxillary sinus is exposed to the oral cavity through an epithelialised fistula. This term signifies pathology and it is not to be confused with oroantral communication (OAC). OAC if left untreated can either heal spontaneously or progress into OAF. The fistulous opening may be situated on the alveolus. Oroantral fistula (OAF) is an abnormal condition of the face where the maxillary sinus is exposed to the oral cavity through an epithelialised fistula. This term signifies pathology and it is not to be confused with oroantral communication (OAC). OAC if left untreated can either heal spontaneously or progress into OAF. The fistulous opening may be situated on the alveolus. The maxillary sinus is known for its thin floor walls and close proximity to the posterior maxillary teeth. Dental procedures such as extraction of these teeth sometimes cause OAC. The posterior maxillary molars and maxillary sinus are innervated by the same branch of nerves which is the maxillary division of trigeminal nerve. This innervation complicates the situation as the pain from maxillary sinus might be indistinguishable from a posterior maxillary toothache. Other known causes of OAC are fracture across the antral floor typically Le Fort I, displacement of posterior maxillary molar roots into antrum, and direct trauma. Extraction of primary teeth are not considered a risk of OAC due to the presence of developing permanent teeth and the small size of a developing maxillary sinus. OAC can happen for many other reasons, such as acute or chronic inflammatory lesions around the apex of tooth root present in close proximity with the maxillary antrum, necrotic lesions of the maxilla, failure of sublabial incision to heal after Caldwell-luc antrostomy, multiple and extensive fractures of the facial region, osteomyelitis of the maxilla, injudicious use of instruments during oral procedures, malignancy of the maxillary sinus, Syphilis, malignant granuloma, radiotherapy, implant denture, removal of a large cyst or resection of large tumour involving maxilla, development of tumour causing bone destruction and loosening of teeth. Clinical examination and x rays can help diagnose the condition. For examples :