Dr suhad almaani

2. Mucous Membrane:
Moist lining of the gastrointestinal tract, nasal passages
and other body cavities that communicates with the
exterior of the body .
( In the oral cavity the lining is called as oral mucous
membrane or oral mucosa)
Function :
MAINLY: protection( physical barrier,immunological
defence )
 Secretion: minor glands, lubrication .
 Sensation: Temperature (heat and cold), touch, pain,
taste .
 Proprioception

3. Skin : Epidermis + Dermis .
Oral Mucosa :
1-Epithelium (keratinized /non keratinized
stratified squamous epithelium ).
2- C.T ( lamina propria ) .
3- Submucosa ( not always present )

4. How is the oral mucosa different from skin?
1. Color :more deeply coloured .
2- Moist surface
3. Absence of hair follicles .
4- Presence of minor salivary glands in oral mucosa .
5. Texture of surface: Oral mucosa is smoother than the skin
6 .Firmness: Oral mucosa varies in its firmness.

6. Oral
mucosa
Lining 60%
Masticatory
25%
Specialized
15%

7. Lining Mucosa:
60% of total mucosa.
Covers the floor of
mouth,ventral(underside)tongue, alveolar
mucosa, cheeks, lips and soft palate.
Does not function in mastication and therefore
has minimal attrition.
Non-keratinized stratified squamous epithelium. soft,
moist, ability to stretch and compress .

8. Masticatory Mucosa:
25% of total mucosa.
Primary mucosa to be in contact with food
Gingiva (free, attached and interdental) and hard palate.
Keratinized stratified squamous epithelium
rubbery, resilient.
Specialized :
Dorsum of tongue ( anterior 2/3 )surface associated with the lingual
papillae
Vermilion zone of the lips

9. There are mainly 2 components :
Oral epithelium ( stratified squamous )
C.T ( L. propria ) / submucosa (loose C.T contains
vessels,nerves ,muscles) .
Distinct B.M between epith./C.T
Indistinct between L.p / submucosa.

11. .
…
…
Keratinized
Stratum basale(
germinativum)
Startum
spinosum(prickle )
Stratum granulosum
Stratum corneum
Non-keratinized
Stratum basale
Startum spinosum
Stratum Intermedium
Stratum Superficiale

12.  Single cuboidal cell layer
 Adjacent to lamina propria
 The only layer where mitosis occurs
 Are all stem cells?
 Least differentiated cells
 Non-keratinocytes cell present

13.  Several cells thick
 Round or Ovoid cells
 Larger and more mature than those of startum
basale
 Contain
- Tonofilaments & involucrin
- Phospholipid granules (Odland bodies) in the
upper part of spinosum
-Increased desmosomes (shrinkage during
preparation gives the spiny appearance)

14.  Cells of further increase in maturation
 Cells larger and flatter
 Contain
- Tonofilaments & tonofibrils that occupy the
cytoplasm
-Keratohyline granules (contain profilaggrin)

15.  In keratinized epithelium
- Highly mature epithelial cells (squames)
-All cellular organelles and nucleus lost
(orthokeratinization)
- In gingiva, nuclei may be retained
(parakeratinization)
- cells are packed with Keratin
 Keratin consist of
- Tonofilaments surrounded by Filaggrin (matrix
protein)
 Desmosomes are weak to allow for shedding
(desquamation)
 Involulcrin is cross-linked to form a cornified envelop
beneath plasma membrane

16.  In non-keratinized epithelium
- No Keratin
- Tonofilaments are less and under-developed
- lack keratohyline granules
- this layer is less distinct
- the outer layers of non-keratinized epithelium
may be termed stratum superficiale
- The layers below may be termed startum
intermedium

22. keratinized
Cells have keratohyline
granules (contain
profilaggrin essential to
stabilize keratin
filaments).
Cells of superficial layers
1-loss of nuclei
completely (
orthokeratinized)or
partially (para
keratinized)
2-No organelles at all
Non -keratinized
Cells lack keratohyaline
granules.
Cells of superficial
layers have nuclei,
organelles.
Only Involuricin protein
is produced
No filaggrin or loricin so
tonofilaments are less
developed and
dispersede

24. CK : intermediate filaments that show high
specificity for epithelial cells .at least
22main CK polypeptides are known.
Function : component of cell cytoskeleton.
component of desmosmes and
hemidesmosomes.(E.bullosa mutant CK14 )
2 CK types :
Basic, high Mwt CK type 2 ( numbers 1-8)
Acidic,low Mwt type 1 ( numbers 9-22)
Each epith.cell express at least one pair
(component of type 1 + component of type 2

25. Masticatory mucosa CK (1,10) (2,11)
Lining mucosa (4,13)
Basal cell keratinocytes for all SSE (5,14)
Hyperproliferative epith.(6,16)
Basal cell Ca.(17)
Odontogenic epith. CK 19
Ventral of tongue (5,6,14 )
Soft palate (7,8,18) high level of 19
Alteration of CK profile indicates dysplastic changes or
pathologic changes e.g masticatory mucosa shows
production of CK 4 indicates gingival inflamation.

26. Keratinocytes
90%
Cells have
tonofilaments
Cytokeratin(type of
intermediate
filaments)
desmosomes
Non-keratinocytes
Not related to
epithelial maturation
Cells lack
tonofilaments( called
Clear cells ) halo
around nuclei when
stained for CK.
No desmosomes
EXCEPT
MERCKLE CELLS

29. Melanocytes: Produce the pigment melanin using the enzyme
tyrosinasedendritic (long process that extend through
upper layer), packed with granules (melanosomes),
located in stratum germinativum, derived from neural
crest cell
Langerhans: Dendritic, contain birbeck granules, located in
the layer above stratum germinativum, derived from bone
marrow precursors, antigen-presenting cells, involved in
contact-hypersensetivity reaction, antitumour immunity
and graft rejection.
Merckle cells: Not dendritic, located in stratum
germinativum of masticatory epithelium, absent in lining
epithelium, closed apposed to nerve fibers, thought to act
as a receptor, derived from neural crest cell, posess
keratin filaments and desmosomes, small membrane
bounded vesicle may liberate neurotransmitter.

30. Superficial papillary layer (associated with epthelial rete
ridges)
Collagen fibers are thin and loosely arranged.
deeper reticular layer :
netlike arrangement of dense collagen fibers (nothing to do
with
reticulin fibers)
Papillary layer has thin and loose collagen fibers with many
capillary loops
Reticular layer has collagen fibers arranged in thick bundles
that are parellel to surface
Lamina propria also contains various cells, blood vessels,
nerves and fibers
(collagen and elastic) embedded in an amorphous ground
substance

31. Structure of L.P :
FIBRES :
Collagen fibers (80% type 1, 18 % type 3 ) run in
bundles
Elastin fibers ( for flexibility ) run singly not in
bundles .
Oxytalan.
GROUND SUBSTANCE :
Hydrated gel og proteoglycans and glycoproteins
CELLS : main cells FIBROBLASTS ( turn over of fibers
and synthesis of ground substance )

34. Basement membrane
Network of type 4 collagen ( non-fibrillar
)
Proteoglycans , glycoproteins
Synthesized by epithelial cells.
Hemidesmosomal attachment.(MMP
autoantibodies agst transmembrane
molecules bullous pemphigoids antigen
BP180,230)
Under E.M lamina lucida (directly under
epith) , lamina densa

37. Surfaces exposed to
shear compressive
forces during
mastication
epithelium :Thick
keratinized
lamina P. :Thick dense
Numerous elongated
Rete pegs.
No submucosa
Hard palate.gingiva
epith :
Non-keratinized
Epithelial junction
with C.T (papillae)
smoother,short
/flexibility
L.P is thinner with
fewer collagen
,more irregular
course,more elastin
Thick submucosa

40. Histology
of Hard
Palate
Thick orthokeratinized (or parakeratinized in areas) epithelium showing
ridges (rugae)
Lamina propria shows long papillae with thick dense connective tissue
In central area NO submucosa is present
Butwhere it joins alveolus submucosa is present since it contains
neurovascular bundle, also fattu zone anteriorly, glandular zone ( minor
salivary glands) posteriorly

41. Soft palate
A: Hard Palate
B; Soft palate
C: Nasal
cavity
1. Nonkeratinized
2. Highly vascularized so more pink
than hard palate
2. Lamina propria and submucosa
present (unlike hard palate when
only lamina propria is noted –
mucoperiosteum)
3. Submucosa contains salivary
glands and muscle soft palate

42. Similar to lips and soft palate
Nonkeratinized stratified squamous
epithelium, lamina propria and submucosa
Submucosa of cheeks contain fat cells along
with lobules of minor salivary
glands and muscle fibers
Cheeks (Buccal Mucosa)

43. Ventral surface of tongue Floor of mouth
Nonkeratinized stratified squamous
epithelium, lamina propria and
submucosa
Extremely dense muscle fibers
interlacing connective tissue fibers
in submucosa
Nonkeratinized stratified
squamous
epithelium, lamina propria
and submucosa
Epithelium is loosely
attached to
lamina propria
No muscle

44. Anterior 2/3 of the tongue (masticatory but
with taste buds )
Filiform papillae (hair like ) dorsum of
tonge,keratinized
Fungiform ( mushroom like) non-keratinized,at
tongue tip
Foliate (leaflike ) post.lat.margin of tongue.
Non-keratinized
Cicumvallate : non keratinized,taste buds
present in epithelium of trench surrounding
it.

46. 1. Filiform papilla: Makes up majority of the papillae and covers the
anterior part
of the tongue. They appear as slender, threadlike keratinized
projections
(~ 2 to 3 mm) of the surface epithelial cells. These papillae facilitate
mastication
(by compressing and breaking food when tongue is apposed to the
hard palate)
and movement of the food on the surface of the tongue. The papillae
is directed
towards the throat and assist in movement of food towards that
direction.
NO TASTE BUDS.

47. 2. Fungiform papilla: (Fungus-like) These are interspersed between the
filiform papilla.
More numerous near the tip of the tongue. Smooth, round structures
that appear
red because of their highly vascular connective tissue core, seen
through a thin,
nonkeratinized stratified squamous epithelium. Taste buds are usually
seen within
the epithelium.

48. 3. Foliate Papilla: (Leaf-like). Present on the lateral margins of
the posterior tongue.
Consist of 4 to 11 parallel ridges that alternate with deep
grooves in the mucosa,
and a few taste buds are present in the epithelium. They
contain serous glands
underlying the taste buds which cleanse the grooves.

49. 4. Circumvallate papilla: (Walled papilla). 10 to 14 in
number these are seen along
the V-shaped sulcus between the base and the body of
the tongue. Large, ~ 3 mm
in diameter with a deep surrounding groove. Ducts of
von Ebner glands (serous
salivary glands) open into the grooves. Taste buds are
seen lining the walls of
the papillae.

51. Microscopically visible barrel-shaped bodies found in the oral
epithelium.
Usually associated with papillae of the tongue (circumvallate,
foliate and
fungiform). Also seen in soft palate, epiglottis, larynx, and
pharynx.
Referred to as NEUROEPITHELIAL STRUCTURES. But most correctly
referred
as epithelial cells closely associated with clib-shaped sensory nerve
endings. These
nerves arise from the chorda tympani in anterior tongue and
glossopharyngeal in
posterior tongue and come to lie among the taste cells. Each taste
bud has ~ 10 to
14 cells. Majority are taste cells with elongated microvilli that
project into the
taste pore. (Epiglottis and larynx – Vagus nerve
Taste Buds: Unique sense organs that contain the chemical
sense for taste

52. Taste Buds in the Human Adult
Location Number
Tongue 10,000
Soft palate 2,500
Epiglottis 900
Larynx/pharynx 600
Oropharynx 250
4 taste sensations: Sweet, salty, sour and
bitter
Sweet and salt: ant tongue
Sour: lateral tongue
Bitter: region of circumvallate papilla

53. Junction between skin and labial mucosa.
Red zone ( epith.is thin and translucent,C.T
contains capillary loop)
Thin keratinized epith. Papillae are long and
narrow no sweat glands
Few sebacous glands`

54. A: Skin
B: Vermillion zone
C: Oral (labial) mucosa
D: Minor salivary glands

55. junction of the mucous membrane of the oral cavity with
the skin of the lip (A). Skin is to the right (B) and is
composed of the epidermis (epithelial layer) and the
dermis (dense connective tissue layer).
-Mucosa (C) on the left, is composed of epithelium and
lamina propria (dense connective tissue layer).
-mucocutaneous junction (A) - the epithelium of the
mucosa is continuous with that of the skin and the lamina
propria is continuous with the dermis.
.

56. Turnover time :
Estimated time necessary to replace all the cells in the
epithelium:
Skin: 52 to 75 days
Gut: 4 to 14 days
Gingiva: 41 to 57 days
Cheek: 25 day
Junctional epithelium of gingiva : 5-6 days
Nonkeratinized epithelium e.g buccal mucosa turns over
faster than keratininzed epithelium hard palate
Clinical correlation: Oral ulcers during cancer
chemotherapeutic treatment ( growth factors )

58. The gingiva is the part of the oral mucosa that
covers the alveolar processes of the jaws and surrounds the necks
of the teeth.75% parakeratinized,10% non- keratinized
,orthokeratinized.
• The gingiva is divided anatomically into:
1. Marginal
2. Attached
3. and Interdental areas

65. Sulcular epith + junctional epithelium.
Sulcular epith.:non-keratinazed SS.
If exposed turned into keratinized SS.
Junctional epithelium is non keratinized SS
BUT IT IS ODONTOGENIC from Reduced
Enamel Epith. Rather than being from oral
mucosa (cytokeratin profile CK 19)
Highest rate of turn-over ( 5-6days)
Has 2 basal laminae(internal with enamel
,external with L.p) Hemidesmosomes present
Protective role (wide intercellular spaces for
passage of crevicular fluids)

72. 1- Dentogingival : from Cementum above alveolar crest to gingiva
2- longitudunal : extends within free gingiva along whole arch.
3- circular : encircle tooth with interdental gingiva and marginal
gingiva .some attach to cementum, bone,adjacent tooth.
4- Alveogingival : crest of alveolar bone ,interseptal bone coronal to
gingiva.
5-Dentoperiosteal : only in labial & ling.gingiva from cementum to
Periosteum (pass over alv.crest )
6-Transseptal : horizontally from root of one tooth to the root of
adjacent one.
7-Semicircular : from cementum of one side of tooth to the opposite
side of same tooth.
8- Transgingival : from cervical cementum to marginal G of adjacent
tooth
9- Interdental : connect buccal & ling. Interdental papillae
10-Vertical : attached gingiva coronally to MG or ID gingva.

74. THANK YOU ……