During FESS, the most important landmark for identifying the maxillary sinus ostium and avoiding injury to the orbit is the:
- A Middle turbinate ground lamella (basal lamella)
- B Ethmoid bulla
- C Uncinate process ✓
- D Superior turbinate
Explanation
The uncinate process is the key surgical landmark in FESS. Its medial surface forms the lateral wall of the middle meatus; its free edge, when removed (uncinectomy), reveals the natural maxillary sinus ostium in the hiatus semilunaris. Critically, the attachment of the superior third of the uncinate process determines whether the frontal recess drains medial to it (into the middle meatus) or lateral to it (into the infundibulum). Injury to the skull base or lamina papyracea is avoided by understanding uncinate process attachments. The basal lamella separates anterior from posterior ethmoids.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.