During mastoid surgery, the surgeon identifies the 'fossa incudis' as a landmark. This structure marks the lateral boundary of which space?

• A Sinus tympani
• B Posterior tympanotomy
• C Aditus ad antrum
• D Facial recess ✓

Explanation

The facial recess is a triangular space bounded superiorly by the fossa incudis (short process of incus), laterally by the chorda tympani nerve, and medially by the facial nerve. Identifying the fossa incudis as the superior landmark allows safe drilling of the facial recess for posterior tympanotomy access. The sinus tympani lies medial to the facial nerve; the aditus is the passageway between the attic and antrum.

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.