Laterally, the zygomatic process of the frontal bone projects inferiorly forming the upper lateral rim of the orbit. This process articulates with the frontal process of the zygomatic bone.
The lower lateral rim of the orbit, as well as the lateral part of the inferior rim of the orbit is formed by the zygomatic bone (the cheekbone).
Superiorly, in the nasal region the paired nasal bones articulate with each other in the midline, and with the frontal bone superiorly. The center of the frontonasal suture formed by the articulation of the nasal bones and the frontal bone is the nasion.
Laterally, each nasal bone articulates with the frontal process of each maxilla.
Inferiorly, the piriform aperture is the large opening in the nasal region and the anterior opening of the nasal cavity. It is bounded superiorly by the nasal bones and laterally and inferiorly by each maxilla.
Visible through the piriform aperture are the fused nasal crests, forming the lower part of the bony nasal septum and ending anteriorly as the anterior nasal spine, and the paired inferior nasal conchae.
The part of the face between the orbit and the upper teeth and each upper jaw is formed by the paired maxillae.
Superiorly, each maxilla contributes to the inferior and medial rims of the orbit.
Laterally, the zygomatic process of each maxilla articulates with the zygomatic bone and medially, the frontal process of each maxilla articulates with the frontal bone.
Inferiorly, the part of each maxilla, lateral to the opening of the nasal cavity, is the body of the maxilla.
On the anterior surface of the body of the maxilla, just below the inferior rim of the orbit, is the infra-orbital foramen (Table 8.1).
Inferiorly, each maxilla ends as the alveolar process, which contains the teeth and forms the upper jaw.
The lower jaw (mandible) is the most inferior structure in the anterior view of the skull. It consists of the body of the mandible anteriorly and the ramus of the mandible posteriorly. These meet posteriorly at the angle of the mandible. All these parts of the mandible are visible, to some extent, in the anterior view.
The body of the mandible is arbitrarily divided into two parts:
The lower part is the base of the mandible.
The upper part is the alveolar part of the mandible.
The alveolar part of the mandible contains the teeth and is resorbed when the teeth are removed. The base of the mandible has a midline swelling (the mental protuberance) on its anterior surface where the two sides of the mandible come together. Just lateral to the mental protuberance, on either side, are slightly more pronounced bumps (mental tubercles).
Laterally, a mental foramen (Table 8.1) is visible halfway between the upper border of the alveolar part of the mandible and the lower border of the base of the mandible. Continuing past this foramen is a ridge (the oblique line) passing from the front of the ramus onto the body of the mandible. The oblique line is a point of attachment for muscles that depress the lower lip.
The lateral view of the skull consists of the lateral wall of the cranium, which includes lateral portions of the calvaria and the facial skeleton, and half of the lower jaw (Fig. 8.19):
Bones forming the lateral portion of the calvaria include the frontal, parietal, occipital, sphenoid, and temporal bones.
Bones forming the visible part of the facial skeleton include the nasal, maxilla, and zygomatic bones.
The mandible forms the visible part of the lower jaw.
Lateral portion of the calvaria
The lateral portion of the calvaria begins anteriorly with the frontal bone. In upper regions, the frontal bone articulates with the parietal bone at the coronal suture. The parietal bone then articulates with the occipital bone at the lambdoid suture.