Frontonasal duct

The frontonasal duct is a duct through which either frontal [air sinus|frontal sinus] drains into the nasal cavity.' Each frontal sinus opens into the frontonasal duct by an opening on the inferomedial part' of the floor of the sinus. The frontonasal duct passes inferior-ward to open either' into the middle [nasal meatus] at the anterior end of' the ethmoidal infundibulum,' or into the Anterior [ethmoidal cells|anterior ethmoidal air cells].'
The duct is lined by mucous membrane.

Clinical significance

fractures may result in damage to the frontonasal duct, resulting in impaired drainage of the frontal sinus and consequent predisposition to intercranial spread of infection, and the development of mucocele in the frontal sinus. Frontal sinus wall fractures may require the frontonasal duct to be sealed and the epithelium of the sinus to be excised.