In cortical mastoidectomy, the surgeon identifies the sinodural angle of Citelli. What is the correct description of this landmark and its content?

• A The angle between the lateral semicircular canal and the aditus, containing the incus body
• B The angle between the posterior canal wall and the facial ridge, containing the chorda tympani
• C The angle between the digastric ridge and the stylomastoid foramen, containing the facial nerve
• D The angle between the tegmen antri and the sigmoid sinus plate, containing sinodural mastoid air cells ✓

Explanation

The sinodural angle of Citelli lies between the tegmen antri superiorly and the sigmoid sinus plate posteriorly. It usually contains mastoid air cells that must be fully exenterated during mastoidectomy to avoid leaving diseased cells behind, and these cells can track toward the petrous apex. Koerner's septum is a separate embryological landmark within the mastoid and should not be confused with this angle.

Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.