Superior View of the Left and Right Temporal Bones. The medial part of the upper surface is the site of the trigeminal impression in which the trigeminal nerve and ganglion and Meckel’s cave sits. Farther laterally is the prominence of the arcuate eminence overlying the superior semicircular canal. Lateral to the arcuate eminences is the tegmen, a thin plate of bone roofing the mastoid antrum, epitympanic area, and external acoustic meatus. The temporal bone articulates anteriorly with the sphenoid bone, above with the parietal bone, and posteriorly with the occipital bone. The zygomatic process of the squamosal part has an anterior and a posterior root, between which, on the lower surface, is located the mandibular condyle. (Image courtesy of AL Rhoton, Jr.)