Chapter 7
•
Head
930
The principal muscles of the cheeks are the buccinators
(Figs. 7.76). Numerous small
buccal glands
lie between the
mucous membrane and the buccinators (Fig. 7.74A). Super-
ficial to the buccinators are encapsulated collections of fat;
these
buccal fat-pads
are proportionately much larger in
infants, presumably to reinforce the cheeks and keep them
from collapsing during sucking. The cheeks are supplied
by buccal branches of the maxillary artery and innervated
by buccal branches of the mandibular nerve.
GINGIVAE
The
gingivae
(gums) are composed of fibrous tissue covered
with mucous membrane. The
gingiva proper
(attached gin-
giva) is firmly attached to the alveolar processes of the man-
dible and maxilla and the necks of the teeth (Figs. 7.76 and
7.78). The gingiva proper adjacent to the tongue is the supe-
rior and inferior lingual gingivae, and that adjacent to the
lips and cheeks is the
maxillary
and
mandibular labial
or
buccal gingiva,
respectively. The gingiva proper is normally
pink, stippled, and keratinizing. The
alveolar mucosa
(unattached gingiva) is normally shiny red and non-keratin-
izing. The nerves and vessels supplying the gingiva, underly-
ing alveolar bone, and
periodontium
(which surrounds the
root[s] of a tooth, anchoring it to the tooth socket), are pre-
sented in Fig. 7.79A & C.
Teeth
The
chief functions of teeth
are to:
• Incise (cut), reduce, and mix food material with saliva
during mastication (chewing).
• Help sustain themselves in the tooth sockets by assisting
the development and protection of the tissues that sup-
port them.
• Participate in articulation (distinct connected speech).
The teeth are set in the
tooth sockets
and are used in mastica-
tion and in assisting in articulation. A tooth is identified and
described on the basis of whether it is
deciduous
(primary)
(A)
(B)
Labial mucosa
Alveolar mucosa
Superior labial
gingiva
Inferior labial
gingiva (gingiva
proper)
I1 I2 C
PM
M
I1 I2
C
PM
M
Alveolar mucosa
(unattached
gingiva)
Vestibular
(mucolabial) fold
Labial frenulum
Vestibular
(mucolabial) fold
Labial mucosa
Vermilion
border of lip
PM
FIGURE 7.78.
Oral vestibule and gingivae. A.
The vestibule and gingivae of the maxilla are shown.
B.
The vestibule and gingivae of the mandible are
shown. As the alveolar mucosa approaches the necks of the teeth, it changes in texture and color to become the gingiva proper. (Courtesy of Dr. B. Liebgott,
Professor, Division of Anatomy, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.)
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