Transcript Slide 1

What is this?
Filiform & Fungiform Papillae
Image 49
• The filiform papillae are roughly conical in
shape. Each contains a small connective
tissue core and a keratinized epithelial
lining. The fungiform papillae are domeshaped and contain a core of connective
tissue with a rich vascular component. The
lining epithelium is relatively thin and is
generally thinly keratinized. H&E, 40x
Filiform Papillae
Filiform & Fungiform Papillae
Image 51
Two fungiform papillae show to
advantage; between them are filiform
papillae.
Fungiform Papillae
Filiform & Fungiform Papillae
Image 53
Here is another view of a fungiform
papilla surrounded by filiform papillae.
H&E, 40x
Fungiform Papilla
Image 55
This is a higher magnification view
of a fungiform papilla. H&E, 100x
Circumvallate Papilla
Image 56
The circumvallate papillae are large mushroom-shaped
structures which may be up to several millimeters in
width. They are characteristically circumscribed by a
trough. Numerous taste buds are located within the
epithelium that lines the walls of the trough. H&E, 40x
Taste Buds
Image 58
Higher power of image 56Circumvallate Papilla
Taste Buds
Image 59
Higher power of image 58. The taste buds appear as
ovoid-shaped structures within the epithelial lining of
the papilla. It consists of sustentacular (supporting)
cells and gustatory neuroepithelial (taste) cells. A taste
pore exits onto the surface of the epithelium from each
taste bud. H&E, 400x
von Ebner's Glands
Image 57
Region inferior to image 56. The
serous glands of von Ebner are located
at the base of the circumvallate papilla
Von Ebner’s glands
Von Ebner's glands (v) are the minor serous salivary glands
associated with the circumvalate papillae. Their ducts open
at the base of the papilla, and the secretions are thought to
play an as yet undetermined role in the taste function of
these papillae. The glands of von Ebner also secrete a potent
lipase that may play a role in gasrtic lipid digestion.
Circumvallate Papilla
Image 65
von Ebner's Glands
Image 66
Region inferior to image 65. Note the
lingual striated skeletal muscle.
von Ebner's Glands
Image 67
Notice the tri-directional arrangement of
the skeletal muscle fibers.
Anterior Lingual Glands
This is a histological section through the anterior part
of the tongue showing the anterior lingual glands (the
glands of Blandin and Nunh) lying between the bundles
of skeletal muscle. These minor salivary glands are
mixed, mostly mucous in character, and their ducts
open on the ventral surface of the tongue.
Mucous vs Serous
Image 37
At higher magnification, observe the cytological
differences between the lightly stained mucous cells
and the deeply stained serous cells. In the mixed acini,
the serous cells form crescent-shaped caps over the
mucous cell groups and are named serous demilunes.
Also observe the striated duct.
What is this?
Bud Stage
Human, frontal section
(10th week).
What are the
Black Arrows in
this picture?
The arrows
are showing
that there has
been a down
growth of the
oral epithelium
into the
underlying
mesenchyme
This light micrograph shows the bud stage of tooth
development. Note that there has been a down growth
of the oral epithelium (e) into the underlying
mesenchyme (m), and the epithelium is separated
from the connective tissue by a distinct basement
membrane. Inferior to the epithelial bud there appears
to be the begining "condensation" of mesenchymal
cells (arrow), which will eventual become the dental
papilla and the dental follicle. None of the distinctive
characteristics of the dental organ (cap stage) have yet
appeared, i.e. there is no recognizable inner and outer
dental epithelia.
What is this?
Meckel's cartilage
What is this?
Nasal Septum
What stage is this?
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Toothbud, late cap stage
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1: outer enamel (dental) epithelium
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2: enamel knot
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3:Stellate reticulum
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4: dental papilla
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5:inner enamel (dental) epithelium
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6: dental follicle
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What stage is this?
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Bell stage
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1: Stellate reticulum
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2: succedaneous toothbud
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3: inner enamel epithelium
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4: enamel (dental) epithelium
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5: dental papilla
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6: Cervical loop
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7:dental follicle
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Enamel
Enamel Lamellae
Image 06
The enamel lamellae appear as
longitudinal cracks in the enamel
(some are cracks) that sometimes
extend into the dentin.
Enamel Tufts
Image 07
Several enamel tufts, which appear as wavy
groups of enamel rods, extend from the
dentinoenamel junction into enamel to about
one quarter of its thickness. Unstained, 100x
Enamel Spindles
Image 09
The enamel spindles appear as short, straight, thin, dark
structures which extend for only short distances into enamel.
They are residual tubules formed when odontoblastic
processes extend across the dentinoenamel junction during
odontogenesis. In ground sections, the odontoblastic
processes disintegrate and are replaced by air which
appears dark in transmitted light. Unstained, 100x
Gnarled Enamel
Image 12
Bundles of enamel rods appear to intertwine
in a highly irregular manner in the cusp region
of teeth to form gnarled enamel. The
phenomenon of gnarled enamel appears to
be an optical illusion. Unstained, 40x
Hunter-Schreger Bands
Image 14
Hunter-Schreger bands appear as alternating light and
dark bands in light microscopy. They are best observed
in polarized or reflected light. What is the underlying
basis for the appearance of this phenomenon?
Unstained, 40x
Dentin
dentinoenamel junction
Lines of Retzius in enamel
Contour lines of Owen in dentin
Dentinal Tubules
Image 25
Lines of von Ebner
Image 36
The lines of von Ebner are oriented in the
horizontal axis at approximately right angles
to the dentinal tubules which run in the
vertical axis. Unstained, 40x
Interglobular Dentin
Image 41
Ground Section
The regions of interglobular dentin appear as black
spaces which are located in the crown of the tooth near
the dentinoenamel junction. Notice that the dentinal
tubules traverse the interglobular dentin. How is
interglobular dentin formed? (Higher magnification of
image 40) Unstained, 200x
Enlarged region of the above photo
Tomes' Granular Layer
Image 42
Tomes' granular layer appears as a black
layer of granular structures which are located
in the peripheral zone of root dentin adjacent
to the cementum. Unstained, 100x
What is 1?
1:Crestal interdental ligments
What is 2?
2: horizontal interdental ligments
What is 3?
3: Oblique interdental ligments
What is 4?
4: apical interdental ligments
Transseptal Fibers
Image 14
Transeptal and horizontal fibers
Epithelial Rests of Malassez
Image 25
The epithelial rests appear as small clusters of epithelial cells which
are located in the periodontal ligament adjacent to the surface of
cementum. They are cellular residues of the embryonic structure
known as Hertwig's epithelial root sheath. Observe the epithelial
rests, cementoblasts and the layer of acellular cementum. Although
the normal function of epithelial rests is unknown, they can develop
into pathological dental cysts.
Junctional Epithelium
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This is a of the
junctional epithelium (je),
the enamel (e),
dentin (d)
and cementum (c).
You can also see fibers of the
dentogingival ligament (black
arrows). The white arrows show
Sharpey's fibers inserting into the
cementum. Junctional epithelium is
originally derived from reduced
enamel epithelium, and the epithelium
cells facing the enamel (or dentin or
cementum) are 'attached' to the hard
surface via a modified basement
membrane. Interestingly, if the
junctional epithelium is removed
surgically, it will reform, even against
an implant surface.
What is this?
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TMJ
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1:Condyle
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2: Lateral Pterygoid Muscle
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3: Articular disc
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