(2) The zygomatic process is a rough triangular eminence that joins the
zygomatic bone. The frontal process projects superiorly from the body. It is connected
to the frontal bone and one of the nasal bones. The alveolar process is a thick spongy
ridge of bone that contains the cavities for the reception of the upper teeth. The
palatine process (figure 2-30) forms a considerable portion of the floor of the nasal
cavity and the roof of the mouth. When the two maxillae are joined together, the
incisive foramen is seen on the midline at the anterior border of the palatine process.
e. Palatine Bones. The palatine bones (figure 2-30) are two L-shaped bones
that contribute to the formation of the lateral wall of the nasal cavity and the roof of the
mouth. Each palatine bone is divided into two parts, a perpendicular plate and a
horizontal plate.
f. Inferior Nasal Conchae. The inferior nasal conchae (figure 2-27) are two
scroll-shaped bones attached to the nasal surface of the body of the maxilla.
g. Vomer. The vomer (figure 2-28) is a flat bone that contributes to the
formation of the nasal septum. It is situated on the midline and is joined posteriorly with
the body of the sphenoid superiorly, with the perpendicular plate of the ethmoid, and,
inferiorly, with the palatine processes of the maxillae and the horizontal plates of the
palatine bones.
h. Mandible. The mandible, or lower jaw bone, (figures 2-27, 2-28, and 2-29) is
the largest bone of the face. It consists of a curved, horizontal body and two
perpendicular rami. The upper portion of each ramus (figure 2-29) is divided by a deep
semilunar depression, the mandibular notch, and is surmounted by two processes, the
coronoid and the condylar. The coronoid process is situated anterior to the mandibular
notch, and the condylar process is situated posterior to the mandibular notch. The
internal (medial) surface of the ramus presents the mandibular foramen. This foramen
communicates with a mandibular canal that lies within the ramus and the body of the
mandible. This canal accommodates blood vessels and nerves to the teeth. The
junction of the posterior border of the mandibular body and the inferior border of the
ramus marks the angle of the mandible. The anterior tip of the body is called the mental
protuberance (chin). A mental foramen is situated on either side of the chin. Along the
superior border of the body is the alveolar ridge, which includes depressions for the
reception of the lower teeth.
2-29. HYOID
The hyoid bone is a horseshoe-shaped bone below the mandible and above the
styloid processes of the temporal bone. It provides surfaces for the attachment of some
of the tongue muscles.
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