During cortical mastoidectomy, the surgeon exposes the angle between the tegmen tympani and the sigmoid sinus plate. This area, called the sinodural angle (Citelli's angle), is surgically important because its contained cells lead toward the:
- A Perilabyrinthine region
- B Hypotympanum
- C Petrous apex ✓
- D Zygomatic root
Correct answer: C. Petrous apex
Explanation
The sinodural angle lies between the tegmen plate above and the sigmoid sinus behind. Cells opening here are the sinodural cells, which extend along the superior petrosal axis toward the petrous apex, so complete exenteration matters in petrositis. The zygomatic root cells lie anteriorly, perilabyrinthine cells surround the labyrinth, and hypotympanic cells are in the floor of the middle ear.
Reference: Diseases of Ear, Nose and Throat, Dhingra, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.