This is supposed to be an anatomical study of an orc's skull. You can notice the differences from a human skull. In general, even though the cranium is proportionally smaller for an orc, the cranial capacity is compensated by the bigger size of the skull, so that the brain capacity is just a little smaller than that of a human. The jaw, muzzle, zygomatic and supra-orbital arches are bigger than those of a human. The jaw and maxillary are oversized to allow the bigger canines. You may observe that the second, smaller pair of tusks are not on the lower jaw, but on the maxillary, curving themselves upward, like those of the wild boars. In fact one of the possible etymologies of the name "orc" in the English language is from the Latin porcus (hog, pig), given to them because of their tusks.