Fig. 5 Endonasal sagittal view. Each meatal space is named for the turbinate that lies immediately above. (ST, superior turbinate; OM, ostium of maxillary sinus; MT, middle turbinate; NV, nasal vestibule; IT, inferior turbinate; ONLD, ostium of nasal lacrimal duct; BE, bulla ethmoidalis; S, sphenoid sinus; HS, hiatus semilunaris; F, frontal sinus; UP, uncinate process; EO, ethmoid ostia)