Fig. 42-8. Lateral aspect of the skull. The pterion is where the parietal and frontal bones, the greater wing of the sphenoid, and the squamous part of the temporal bone approach one another. The temporal fossa is bounded by the temporal lines above and the zygomatic arch below. The infratemporal fossa (see fig. 42-11) lies medial to the ramus of the mandible. Click for high resolution image.