During cortical mastoidectomy, the surgeon must identify Macewen's triangle (suprameatal triangle) to safely enter the mastoid antrum. Which of the following correctly identifies this triangle's landmarks?

• A Mastoid tip, zygomatic arch, and external acoustic meatus
• B Posterosuperior wall of external acoustic meatus, suprameatal crest, and spine of Henle ✓
• C Posterior wall of external meatus, temporal line, and sigmoid sinus
• D Suprameatal crest, root of zygoma, and mastoid emissary vein

Explanation

Macewen's triangle (suprameatal triangle) is bounded anteriorly by the posterosuperior wall of the external acoustic meatus, posterosuperiorly by the suprameatal crest (posterosuperior curved line), and anteroinferiorly by the spine of Henle (suprameatal spine). The mastoid antrum lies approximately 1.25 cm deep to the center of this triangle in adults, making it the surgical entry point.

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.