Trigeminal opening

The trigeminal opening (porus trigeminus) is the opening of the cavum trigeminal (Meckel's cave) in the dura mater, on the posterior surface of the petrous apex, and in front of the prepontine cistern.

The trigeminal opening is bounded superiorly by the posterior clinoid fold, inferiorly by the inferior petrosal sinus, medially by the posterior clinoid process and laterally by the apex of petrous part of temporal bone.