Suprameatal triangle

In the temporal bone, between the posterior wall of the external acoustic meatus and the posterior root of the zygomatic process is the area called the suprameatal triangle, mastoid fossa, or MacEwen's triangle, through which an instrument may be pushed into the mastoid antrum.

In the adult, the antrum lies approximately 1cm deep to the suprameatal triangle. This is an important landmark when performing a cortical mastoidectomy. The supreameatal triangle lies deep to the cymba conchae.