Virtual Mapping of the Frontal Recess: Guiding Safe and Efficient Frontal Sinus Surgery.

ObjectiveTo define relationships between the frontal sinus opening, ostia of other frontal recess cells, and endoscopic landmarks and to develop a clinically useful framework to guide frontal sinus surgery.Study DesignRetrospective review.SettingTertiary care academic referral center.MethodsAdult patients with computed tomography (CT) without sinonasal pathology were included. Virtual endoscopy (using OsiriX) and corresponding CT reconstructions were used to identify all visible ostia in the frontal recess and characterize their positions in spaces between the uncinate/agger nasi (U), bulla ethmoidalis (EB), and middle turbinate (MT).ResultsTwo hundred sides in 100 patients (median age 51 years, 62% female) were analyzed. The “center” of each map was defined as the intersection of spaces between U, EB, and MT. The frontal sinus opening was in the “center” in 53% of frontal recesses, lateral to this position in 29%, and anterior in 11%. When the frontal sinus opening was at the “center,” anterior ostia dra...