The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus and lateral to the styloid process.
This page contains content from the copyrighted Wikipedia article "Mastoid process"; that content is used under the GNU Free Documentation License (GFDL). You may redistribute it, verbatim or modified, providing that you comply with the terms of the GFDL.
