CHAPTER 14
Oral Cavity
259
The
oral cavity
is lined by oral mucosa, which can be divided into
masticatory mucosa
(gingiva, hard palate),
lining mucosa
(lips,
soft palate, cheeks, inferior surface of the tongue, fl oor of the mouth), and
specialized mucosa
(tongue). This illustration represents
the lip and a tooth and the mucosa covering these structures. The lip is covered externally with
skin
to the
vermilion zone (inter-
mediate zone
or
mucocutaneous
junction
); the vermilion zone continues to the
labial mucosa
, which is the lining mucosa on the
internal surface of the lip. The alveolar process of the jaw (containing the tooth roots) is covered by
alveolar mucosa
(lining mucosa)
and
gingiva
. The junction between the lining mucosa and gingiva is the
mucogingival junction
. The tooth can be divided into three
parts:
crown
,
cervix
, and
root
. The crown is the part of the tooth projecting into the oral cavity and has two different deF
nitions:
The
clinical crown
is the part of the crown which is visible in the mouth; the
anatomical crown
is the part of the tooth covered by
enamel. The root is covered by the gingiva or is inside the
bony socket
. The region between the crown and root is the cervix (neck).
The
gingival sulcus
is the space between the free gingiva and the enamel; it is normally 0.5 to 3.0 mm in depth.
Alveolar (lining)
Alveolar (lining)
mucosa
mucosa
Alveolar (lining)
mucosa
Dentin
Dentin
Dentin
Apical foramen
Apical foramen
Apical foramen
Alveolar bone
Alveolar bone
(process)
(process)
Alveolar bone
(process)
Cervix
Root
Crown
Gingiva
Gingiva
Gingiva
Dental pulp
Dental pulp
Dental pulp
A
n
a
to
t
o
m
ic
i
c
a
l c
l
c
ro
r
o
w
n
Anatomic
a
l crown
Clinical crown
C
l
i
n
i
c
a
l
c
r
o
w
n
Clinical crown
Enamel
Dentin
Labial (lining)
Labial (lining)
mucosa
mucosa
Labial (lining)
mucosa
Dentogingival
junction
Mucogingival
junction
Gingiva
(masticatory mucosa)
Vermilion zone
(intermediate zone
mucocutaneous
junction)
Skin
Enamel
Enamel
space
space
Enamel
space
Sulcus
Sulcus
epithelium
epithelium
Sulcus
epithelium
Free gingiva
Free gingiva
Free gingiva
Gingiva sulcus
Gingiva sulcus
Gingiva sulcus
Gingival
epithelium
Junctional
epithelium
Alveolar
bone
labial sulcus
l
a
b
i
a
l
s
u
l
c
u
s
Labial sulcus
Figure 14-1.
Overview of the oral mucosa and teeth.
Lower left, H&E,
3
18
If the depth of the
gingival sulcus
is over 3
mm, these spaces are called
gingival
or
periodontal pockets
. These pockets represent
an abnormal condition. An accumulation of debris and microbes in the pockets may cause damage to the
periodontal ligament
(PDL)
. ±or tooth details, see ±igure 14-7.
I.
Lining mucosa
(covering of inner surface of the lips and
cheeks, soft palate, inferior surface of the tongue, and fl oor
of the mouth)
A.
Epithelium
: nonkeratinized stratiF ed squamous epithelium
B.
Lamina
propria
: connective tissue with many elastic F
bers
and few collagen F bers
C.
Submucosa
: connective tissue with minor salivary glands
and their ducts
II.
Masticatory mucosa
(covering of gingiva and hard
palate)
A. Epithelium
: keratinized stratiF ed squamous epithelium
B.
Lamina
propria
: connective tissue with few elastic F
bers
and many dense collagen F
bers
C. No
submucosa
III. Specialized mucosa (tongue)
A. Filiform
papillae
: no taste buds
B.
Fungiform
papillae
: taste buds on apical surface of the
papilla—sweet, sour, salty
C.
Circumvallate
papillae
: taste buds in lateral wall of the
papilla—bitter
D. Foliate
papillae
: taste buds in lateral wall of papilla
Structures of the Oral Mucosa
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