Prenatal evaluation of bidirectional epignathus: comparison of ultrasonography and magnetic resonance imaging.

Epignathus is an unusual, benign, congenital teratoma of the hard palate. Most of these teratomas are unidirectional and protrude through the mouth. Hence, the prognosis depends on the size of the tumor and degree of face distortion and airway obstruction. Occasionally, intracranial extension of the tumor is present, involving and destroying the brain tissue, resulting in a poor prognosis. The authors describe 2 cases of bidirectional epignathus, showing the different findings on ultrasonography and magnetic resonance imaging.