👉 A petromastoid is a type of bone in the human body. It is the smallest part of the skull and is located at the base of the brain, just under the front of the frontal lobe. This region is known as the petrous portion of the skull because it is the largest part of the skull that faces the outside world. The petromastoid is composed of a layer of bone called the dura mater, which covers the skull and provides support for the brain and
