chapter  7
Pathologies of the Oral Mucosa
Pages 16

DEFINITION An oronasal or oroantral fistula is a defect in the gingival or palatine tissues and maxillary or incisive bone, which results in a communication between the oral and nasal cavities1. An oronasal fistula (ONF) is defined as a defect rostral to the mesial root of the maxillary third premolar, while a defect distal to that is considered an oroantral fistula2.