Note 2 — Chapter I · The Vocal Instrument
Reading edition
Dr. Fillebrown's paper, A Study of the Relation of the Frontal Sinus to the Antrum, was read before the American Dental Association, at Saratoga, August 5, 1895. His investigation showed that the funnel-shaped passage known as the infundibulum extends from the frontal sinus directly into the antrum or maxillary sinus. This was afterwards confirmed by Dr. W.H. Cryer and others.