There are twenty-two bones in the head. Eight of these bones compose the brain case and fourteen bones compose the face. The brain case is bounded in front by the frontal bone or forehead, which extends from the root of the nose to the crown of the head and laterally to the sides of the temples. The two malar bones, or cheek bones, are facial bones, each united to four other bones forming a part of the zygomatic arch which spans the space from cheek to ear. Above, the malar or cheek bone joins the forehead at its outer angle; below, it joins the superior maxillary or upper jawbones. The two superior maxillary bones constitute the upper jaw and cylinder that hold the upper row of teeth. They are attached above to the cheek bones and eye cavities. The nasal bones form the bridge of the nose.
3 ZYGOMATIC ARCH
5 SUPERIOR MAXILLARY
6 INFERIOR MAXILLARY
The inferior maxillary or lower jawbone is the lower border of the face. It is shaped like a horseshoe, its extremities ascending to fit into the temporal portion of the ear. It is a mandible, working on the principle of a hinge moving down or up as the mouth opens or closes, but with a certain amount of play, sideways and forward, so that when worked by the masseter muscles the food is not simply hammered or flattened, but ground by the molar or grinding teeth. The masseter muscle extends from under the span of the zygomatic arch to the lower edge and ascending angle of the lower jaw. It is the large muscle raising the lower jaw, used in mastication. It fills out the side of the face, marking the plane which extends from the cheek bone to the angle of the jaw.
3 Buccinator (cheek muscle)
OCCIPITAL EMINENCES, RIDGES AND DEPRESSIONS
OF THE SKULL
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