Internal maxillary artery variability in the pterygopalatine fossa.

The third segment or pterygopalatine branch of the internal maxillary artery has variable branching in the pterygopalatine fossa. This variability in branching can lead to failure in controlling persistent nasal epistaxis by transantral ligation. Although the surgical approach has been previously studied, a systematic classification of this branching has not been previously reported. Through the performance of serial cadaver dissections in the PPF, we have demonstrated the anatomic course and variations of this third segment and offer a relatively simple classification system.