The oral mucosa is the moist lining of the oral cavity that continues with the skin and esophagus. It has three main functions - protection, sensation, and secretion. It protects the deeper tissues from mechanical forces and toxins, senses stimuli like temperature and pain, and secretes saliva through minor salivary glands. The oral mucosa varies between keratinized mucosa covering areas like the gingiva and hard palate, non-keratinized mucosa in areas like the floor of the mouth and cheeks, and specialized mucosa bearing taste buds on the tongue.

1. Oral Mucosa

2. ORAL MUCOUS MEMBRANE:
The moist lining of the oral
cavity that is in continuation
with the exterior surface of
skin on one hand and oesophagus
on the other

3. ORAL MUCOUS MEMBRANE :

4. ORAL MUCOUS MEMBRANE :
•Located anatomically between skin
& GIT
•Shows some of the properties of
each

5. Functions of Oral Mucosa….
 Protection
 Sensation
 Secretion
 Thermal regulation
 Lubrication

6. Functions of Oral Mucosa….
Protection:
Separates & protects deeper tissues &
organs from environment
Shows number of adaptations of
epithelium & CT to withstands insults of
mechanical forces & surface abrasions
Acts as major barrier to threats of toxic
substances produced by
microorganisms

7. Functions of Oral Mucosa….
Sensation:
Provides considerable information about events
within oral cavity
Lips & tongue perceive stimuli outside the mouth
Receptors respond to temp, touch & pain
Tongue has taste buds
Receptors for reflexes of swallowing, gagging,
salivating

8. Functions of Oral Mucosa….
Secretion:
Minor salivary glands associated with
oral mucosa & ducts of major salivary
glands open into oral mucosa– ‘saliva’-
maintance of moist surface
Sebaceous glands frequently present-
insignificant secretion

9. Functions of Oral Mucosa….
Thermal Regulation:
Considerable body heat is dissipated
through oral mucosa by panting --(DOG)
In human beings- no obvious
specializations of the blood vessels
exist for control of heat transfer

10.  covers all structures inside the oral
cavity except the teeth.
 it consist of epithelium & lamina
propria lining all the surfaces of the
oral cavity.
 it varies in color from pink to brownish
depending on an individual's skin color
Clinical features

12. Clinical features

13. Clinical features
Factors responsible for Colour :
Concentration & dilatation of small
blood vessels in the underlying
connective tissue
Thickness of epithelium
Degree of keratinization
Amount of melanin pigment in the
epithelium

14. Clinical features
Sebaceous glands are present in the upper lip &
buccal mucosa
Fordyce's spots
Papillae on the dorsum of tongue
Rugae of the palate
Stippling on gingiva
Lining mucosa of lips & cheeks is soft & pliable
Gingiva & hard palate are firm

15. Organization of oral mucosa
2 parts of oral cavity-
Outer vestibule-bounded by the lips
& cheeks
Oral cavity proper-separated from
the vestibule by alveolus bearing the
teeth & gingiva

16. Boundaries
•Superiorly-hard & soft palate
•Inferiorly-floor of the mouth & base of the tongue
•Posteriorly-pillars of fauces & tonsils

17. Classification of oral mucosa
Depending on function
Masticatory mucosa Lining mucosa Specialized mucosa

18. Masticatory mucosa
It’s 25% of total mucosa.
It doesn’t stretch and is attached to bone.
During mastication it bears chewing forces.
It covers Gingiva [free{marginal}attached
and interdental] & hard palate.
Primary mucosa to be in contact with food
during mastication.
MASTICATORY MUCOSA IS USUALLY
KERATINIZED.

19. Lining mucosa
It’s 60% of total mucosa.
It’s exposed to very mild forces.
It 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.

20. Specialized mucosa
•It’s also called sensory mucosa as it bears taste
buds and specialized papillae.
•It’s 15% of total mucosa
•Dorsal surface of tongue

21. ORAL MUCOUS MEMBRANE
Epithelium Connective tissue
Component tissues & glands

22. Component tissues & glands
Interface between the epithelium &
connective tissue is irregular
Connective tissue papillae interdigitate with
rete ridges or pegs
Basal lamina is present at the interface
between the epithelum & connective tissues
Submucosa separates the oral mucosa from
the underlying bone or muscle
Gingiva &parts of hard palate - no
submucosa - mucoperiosteum

23. ORAL MUCOUS MEMBRANE

24. ORAL MUCOUS MEMBRANE

25. ORAL MUCOUS MEMBRANE

26. Component tissues & glands
Minor salivary glands are situated in
the submucosa
Sebaceous glands lie in the lamina
propria
Infiltration of lymphocytes & plasma
cells in the connective tissue

27. Oral Epithelium
•Stratified squamous epithelium
Depending upon location :
•Keratinized
•Non keratinized (tissue are :-floor of mouth,
inner lining of cheek, sublingual tissues
Para
Ortho

28. Keratinization
process by which epithelial cells are
exposed to external environment lose
their moisture & replace by horny
tissue which contain keratin
involves series of biochemical &
morphological events that occurs in
the cell as it progresses from basal
layer to stratum corneum

29. Keratinization

30. Keratinized epithelium
4
layers
Stratum
spinosum
Stratum
granulosum
Stratum corneum
Stratum basale

31. Keratinized epithelium

32. Stratum basale
•Layer of cuboidal cells adjacent to the basal lamina
•Cells are capable of division & can synthesize DNA .

33. Stratum basale
Single layer of cuboidal cells
New cells are generated
Basal cells & parabasal spinous cell-
stratum germinativum

34. Stratum basale
2 cell population
Serrated Non Serrated
Packed with
tonofilaments
Slowly cycling stem
cells

35. Stratum spinosum
•Irregularly polyhedral & larger than
basal cells
•Cells are joined by intercellular bridges
•Cells frequently shrink away from each
other, remaining in contact only at points
known as intercellular bridges or
desmosomes
•Basal & prickle cell layer together
constitute from half to two thirds of the

36. LINING MUCOSA
 It’s 60% of total mucosa.
 It’s exposed to very mild forces.
 It 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.
 It’s NON-KERATINIZED & SOFT.

37. SPECIALIZED MUCOSA
It’s also called
sensory mucosa
as it bears taste
buds and
specialized
papillae.
It’s 15% of total
mucosa.

38. Masticatory
Lining
Masticatory:
Hard palate
Gingiva
Lining:
Soft palate
Ventral tongue
Floor of mouth
Cheeks
Lips
Specialized:
Dorsal of the tongue
Specialize
d
CHEEK
SOFT
PALATE

39. WHAT IS KERATINIZATION ??
 It’s a process by which epithelial cells are
exposed to external environment lose their
moisture & replace by horny tissue which
contain keratin.
OR
 The process of keratinization invloves series
of biochemical & morphological events that
occurs in the cell as it progresses from basal
layer to stratum corneum.

40.  Event that occurs in this are:-
a. Gradual flattening of cell
b. Disappearence of nucleus
c. Increased prevelence of tonofilaments
d. Increased prevelence of KERATOHYLINE
GRANULES (granules in the stratum
granulosum)
 Its more resistance to infections & irritation
than non keratinized epithelium.

41. PARAKERATINIZATION
A pattern of keratinization characterized by
incomplete keratinization of the cells in the stratum
corneum. The cells are flattened and composed
primarily of packed tonofilaments. However, the cells
may retain remnants of nuclei and other organelles.
ORTHOKERATINIZATION:-
A form of keratinization where the cells of the
stratum corneum become very flat, loose their
nuclei and cytoplasmic organelles and are now
composed of densely packed tonofilaments
cemented by filaggrin.

42. FUNCTIONS OF THE ORAL
MUCOSA
Protection
Sensation
Secretion
Thermal regulation

43. PROTECTION
Oral Mucosa separates,& protects deeper
tissue /organs in oral regions from the
following:-
[a] Environment of oral cavity.
[b] Mechanical forces of biting & mastication ,to
surface abrasion from hard particle in diet.
[c] Microorganisms may cause infection if they get
access into the underlying tissue.
[d] Toxins produced by micro organisms.

44. SENSATION
Rich innervations of oral mucosa
makes it a good receptor of
temperature ,touch, pain, thirst.
Certain reflexes such as swallowing,
etching, gagging and salivation.

45. Secretion:
→Various major /minor /mucous and
serous salivary glands open into the oral
cavity & makes it moist which helps in
mastication ,swallowing and digestion of
the food.
→The major secretion associated with oral
mucosa is SALIVA.

46. Thermal Regulation:
→Important in dogs (due to
considerable amount of body heat)
→There is no specialized blood vessels
for controlling heat transfer in
human oral mucosa ,so it plays little
part in regulation of body
temperature.

47. BOUNDRIES OF ORAL CAVITY
 SUPERIOR BORDER
Formed by hard and soft palate
 INFERIOR BORDER
Formed by mouth and base of tongue
 POSTERIOR BORDER
Pillars of fauces and tonsils

48. FAUSES:- a Latin plural word for
throat
 In anatomy it’s the hinder part of the
mouth, which leads into the pharynx.
 The fauces are regarded as the two
pillars of mucous membrane. One being
anterior, known as the palatoglossal
arch and the second is posterior, the
palatopharyngeal arch. Between these
two arches is the palatine tonsil.

49. HISTOLOGY OF ORAL MUCOSA

50. HISTOLOGY OF ORAL MUCOSA
 These layer separated by:-
(a)BASAL LAMINA [originate by
epithelium]
(b)BASEMENT MEMBRANE
[originate by connective tissue]
 The connective tissue projection into
epithelium called PAPILLA.
 The epithelium projection into lamina
propria are called EPITHELIAL

51. ORAL EPITHELIUM
 Its ECTODERM in origin {except the tongue
which is ENDODERMAL in origin}
 Its STRATIFIED SQUAMOUS EPITHELIUM.
 At base the cells varies from cuboidal / low
columnar to flat squamous cells
 It maintains the structural integrity by system
of continuous cell renewal in which cells are
produced by mitotic division.

52. During migration of cells numerous
morphological & biochemical
changes occur in the formation of
dead cells that’s packed with large
number of keratin filament, These
cells form protective surface layer &
gradually shed off, this entire
sequence of even from mitosis at
the basal layer to the ultimate
desquamation is k/a KERATINIZATION

53. CELL DIVISION IN ORAL
EPITHELIUM
PHASES
METAPHASE
ANAPHA
SE
TELOPHASE
PROPHASE

54. LAYERS OF EPITHELIUM
Depending upon location
epithelium may be divided
into:-
Keratinized
Non keratinized (tissue are :-
floor of mouth, inner lining of
cheek, sublingual tissues.

55. DEPENDING UPON NATURE OF
KERATINIZATION
KERATINIZED MUCOSA CAN BE
ORTHOKERATINIZ
ED
In this process of
keratinization is
normal with
formation of
acellular keratin
layer on surface
-- no nuclei
present
{e.
PARAKERATINIZE
D
.
pyknotic nuclei
retained
They don’t show
stratum corneum
& stratum
granulosum

56. KERATINIZED ORAL EPITHELIUM CONSISTS OF 4
LAYERS

59. Keratinized epithelium

60. NON-KERATINIZED ORAL EPITHELIUM CONSISTS
OF 4 LAYERS

61. NON KERATINIZED EPITHELIUM

63. STRATUM BASALE
 Its also k/a proliferative /
germinative layer.
 Cells are capable of
division & can synthesize
DNA .
 Cells are cuboidal &
columnar cells adjacent
to basement membrane

64. THERE ARE 2 TYPES OF BASAL CELLS
• Packed with
tonofilaments
SERRATED
• made up of slowly
cycling stem cells [give
rise to amplifying cell
for cell division]

65.  Serrated basal cells are single layer cuboid
cells ,these are packed with tonofilaments.
 Have protoplasmic process which projects from
basal surface towards connective tissue, where
hemidesmosomes are present.
 Adjacent cells consist of adjacent cell
membrane & pair of denser region & are
attached by desmosomes
 Cell junction may be present [tight ,close & gap]

66. THE CELL IN THE BASAL
LAYER ARE OF 2 TYPES:-
Progenitor
cells:-
proliferates &
give rise to
new cells.
Maturing cells/
keratinocytes
cells:-
migrates & matures
& eventually shed
off.

67. Protein synthesis activities are
indicated by ribosomes & RER.
Only basal cells can divide.(basal
cells & parabasal spinous cells k/a
STRATUM GERMINATIVUM.)
MAIN FEATURE OF STRATUM
BASALE IS CELL DIVISION

68. STRATUM SPINOSUM
 Also k/a prickle cell layer
[ because of cell shape]
When cells of this layer
shrinks away ,remaining in
contact only at 1 point k/a
INTERCELLULAR BRIDGE/
DESMOSOMES which gives
cells a spiny like profile.

69. Spinous cells are irregularly
polyhedral & larger than basal cell.
The intercellular spaces contain
glycoprotein, glycosaminoglycans,
& fibronectin.

72. STRATUM GRANULOSUM
 Cells are flat & wide [3-5 cells thick] larger
than spinous layer.
 Prominent in keratinized epithelium &
deficient in non keratinized epithelium.
 Having numerous dense , small
KERATOHYLINE GRANULES (granules in
the stratum granulosum ,which helps in
production of dead layer of cells on skin
surface), stains intensely with basic dye.

73.  Under light microscope,
granules are basophilic
[blue with hematoxylin
stain] & under electron
microscope they are
dense [appearing
black]

74. STRATUM CORNEUM
o It consist of tightly packed
cornified cells.
o Intercellular junctions (ICJ)
between the flattened cells are
marked ,flat cells
devoid of nuclei & packed with
keratin filament. This form of
keratinization is referred to as
orthokeratinization, i.e. complete
keratinization of the epithelial
cells.
o Orthokeratinized epithelia
provide the best protection
against mechanical injury.

75.  The cells contain densely packed
Tonofilaments.
 They continuously shed off & replaced by
migrating cells from underlying layers
 Cells found in this layer are compact
& dehydrated .

76. DIFFERENCES BETWEEN
KERATINIZED EPITHELIUM NON KERATINIZED
EPITHELIUM
4 LAYERS ARE PRESENT IN PLACE OF ST. GRANULOSUM
& CORNEUM
ST.INTERMEDIUM & ST
SUPERFICIALE ARE PRESENT
INTERCELLULAR SPACES ARE
MORE
LESS CONSPICUOUS
THEREFORE DON’T HAVE
PRICKLY APPEARANCE.
DO STAIN INTENSELY WITH
EOSINOPHILIC STAIN
DOESN’T STAIN INTENSELY WITH
EOSINOPHILIC STAIN
DO PRODUCE CORNIFIED
SURFACE.
DOESN’T PRODUCE CORNIFIED
SURFACE.
TURN OVER & MITOTIC RATIO IS
LESS
TURN OVER & MITOTIC RATIO IS
MORE
SURFACE IS NOT FLEXIBLE & SURFACE IS FLEXIBLE & CAN

77. LAMINA PROPRIA
 The lamina propria is the connective tissue under
the epithelium.
 It consists of:
(a)The papillary layer between
the rete ridges
(b)The reticular layer (deeper)

79. ORAL MUCOUS MEMBRANE

80.  Lymphocytes are common cells found in
lamina propria.
 Mast cells
 Macrophages
 Fat cells
 Plasma cells
 Eosinophils undifferentiated cells are also
found in this.

81. SUBMUCOSA
 It’s a connective tissue layer.
 Attaches lamina propria of oral mucosa to
underlying bone /muscle.
a) Glands
b) Blood vessels
c) Nerves
d) Adipose tissue
Are present in it.

82. Large blood vessels enter
the submucosa & divide
here into smaller
branches.(due to which
subepithelial capillary
network in papillae is
formed.

83. NERVE SUPPLY :-
 Nerve supply to oral mucosa is sensory.
 Nerve fibers are myelinated previously which
loses myelin sheath before splitting into their
ends.
 The smooth muscles of blood vessals are
supplied by non-myelinated visceral nerve
fibers. They form network in reticular layer of
lamina propria that finally terminates in a
SUBEPITHELIAL PLEXUS.

84. KERATINIZED AREAS
MASTICATORY MUCOSA
 Area that bears masticatory forces &
compression form masticatory mucosa.
 Areas are:-

85. GENERAL INTRODUCTION :-
 Epithelium of masticatory mucosa is thicker
than other regions.
 Its ortho/parakeratinized
 Having greater number of papillae/unit area
of mucosa.

86. HARD PALATE
Lamina
propria
SUBMUCOSA
Covering
Epithelium

87. COVERING EPITHELIUM
Epithelium of hard palate is thick
orthokeratinzed.
[some parts may show
parakeratinization],stratified
squamous epithelium &
anterolaterally its transverse
palatine ridges {rugue}.

88. LAMINA PROPRIA
It shows long papillae &
dense network of thick
collagen tissue especially
under
Rugue. Blood supply is
moderated by short
capillary loops

89.  The junction between the epithelium &
underlying lamina propria is corrugated
& the papillae are long & elongated to
prevent epithelium from being tipped
under masticatory forces.

90. ZONES OF HARD PALATE
Gingival region-
adjacent to teeth.
Palatine raphe-
extending from the
incisive or palatine
papilla posteriorly.
Anterolateral fatty
zone between raphe &
gingiva.
Posterolateral
glandular area between
the raphe & gingiva.

91. GINGIVAL AREA & MEDIAN PALATINE RAPHE
 These don’t have the submucosal layer beneath
the lamina propria
 They are directly attached to bone.
 Thick layers of submucosa are present in wide
region extending b/w palatine gingiva & palatine
raphe
 A dense band of fibrous connective tissue joins
lamina propria to the mucoperiosteum( there fore
its immovable)

92.  The thick submucosa in palatal region is divided
into irregular compartments :-
Anterior part -- filled with adipose tissue.
Posterior part –with glands.
 Glandular zone extends onto soft palate.
 Oral mucosa of hard palate contains the
ANTERIOR PALATINE NERVES & BLOOD
VESSALS which passes through the junction of
alveolar process & horizontal plate of hard palate.

93. ZONES OF HARD PALATE WHICH DIFFERS FROM
SUB MUCOSAL LAYER
 Gingival region
 Palatal raphe
 Anteriolateral area or fatty zone between the raphe
& gingiva
 Posterolateral area or glandular zone between the
raphe & gingiva
The zone that don’t have a submucosal layer occur
peripherially where palatine tissue are identical with
gingiva & along the midline of hard palate .

94. INCISIVE PAPILLA
 Its situated in the
midline of the hard
palate.(immediately
posterior to maxillary
CI)
 It’s a projection which is
composed of dense
connective tissue.
 It overlies the oral
opening of incisive
canal.

95. INCISIVE CANAL
 It contains remnants
of oral part of
(a)Nasoplatine duct
(b)Nasoplatine nerve &
vessals

96. NASOPALATINE DUCT
 Its lined by simple or
pseudostratified
columnar epithelium
which is rich in
GOBLET CELLS.
 Its vestigial in human
beings & functional in
lower
mammals(JACOBSON
’S ORGAN OF
OLFACTION).

97. PALATINE RUGUE
 Its anterior 1/3rd
mucosa of hard palate
which extends laterally
from incisive papilla &
anterior part of raphe.
 Laterally its supported
by submucosal
cushion of adipose
tissue.
 Core is composed of
dense connective
tissue because of
which its immovable.

98. EPITHELIAL PEARL
 Are circular arranged ,keratinized epithelial
cells.
 These are remnants of eithelium formed
during fusion of palatine processes.
 May be found in lamina propria (in the region
of incisive papilla)

99. GINGIVA
 Part of the oral
mucosa that
covers the
alveolar
processes of the
jaws and
surrounds the
neck of the teeth.

100. PARTS OF GINGIVA
 It’s consist of 2 parts :-
i. The part facing the oral cavity is
MASTICATORY MUCOSA ,which is
orthokeratinized or parakeratinized.
ii. The part facing the tooth that forms the
gingival sulcus & joins gingiva to tooth, its
non-keratinized.

101. DIVISIONS OF GINGIVA
 FREE GINGIVA
 GINGIVAL SULCUS
 ATTACHED GINGIVA
 INTERDENTAL GINGIVA

102. FREE GINGIVA:
 Also k/a marginal gingiva.
 It’s a border of gingiva
surrounding the teeth in a collar
like manner
 Its demarkated from attached
gingiva by a shallow linear
depression called FREE
GINGIVAL GROOVE which run
parallel to gingival
margin(distance is 0.5-1.5mm )
 Its 1mm wide
 Forms soft tissue wall of gingival
sulcus.

103. ATTACHED GINGIVA
 It’s the region between the free gingival groove ,
alveolar mucosa & mucogingival junction.

104.  Its firm , resilient & tightly bound to
underlying periosteum of alveolar bone.
 Its width which is the distance between MGJ
& PROJECTION on the external surface of
the bottom of gingival sulcus increases with
age & in supra erupted teeth.
 in incisor region
3.5 - 4.5 mm in maxilla
3.3 - 3.9mm in mandible
 width in premolar region
1.9mm in maxilla
1.8mm in mandible

105. GINGIVAL SULCUS
A shallow groove between the
marginal gingiva and the tooth
surface, bound by sulcular
epithelium laterally and junctional
epithelium apically .
It’s V shaped & in healthy
individuals , the depth of gingival
sulcus is 1.8-2mm.
The probing depth of normal
gingival sulcus is 2-3mm

106. INTERDENTAL GINGIVA
 Is the part of gingiva that ocupies the gingival
embrasure (fills the space between the 2
adjacent teeth)

107.  Its having 3 shapes which depends on
location & width of contact point between the
2 adjacent teeth:-
 1)Pyramidal (between anterior teeth)
 2) Tent shape (between posterior teeth)
 3) Triangular in vestibular view

108. INTERDENTAL GROOVES
 The gingiva appears slightly depressed
between 2 adjacent teeth which forms
vertical folds called INTERDENTAL
GROOVE.
 The interdental papilla can be pyramidal or
have a "col" shape

110. COL
 In between the buccal
& lingual area peaks of
interdental gingiva of
posterior tooth
generally the central
concave area fits
below the contact
point, this depressed
part of interdental
papilla is covered by
thin non keratinized
epithelium & k/a ‘COL’

112. BLOOD SUPPLY OF GINGIVA
 Its derived from periosteal vessels or
branches of alveolar arteries.
 Blood vessels runs through interdental
septa,perforates it through its crest & enters
gingiva then forms loops within connective
tissue

113. LYMPHATIC SUPPLY OF GINGIVA
 Lymph from gingiva is drained into
submandibular & submental lymph nodes.

114. NERVE SUPPLY OF GINGIVA
 Gingiva is innervated by :----
I. terminal branches of periodontal nerve
fibers
II. Infraorbital
III. Palatine
IV. Lingual
V. Mental &
VI. Buccal nerves

115. AGE CHANGES IN GINGIVA:-
 With aging apical margination of
dentogingival junction occurs.
 Epithelium becomes thinner
 Flattening of epithelium connective tissue
junction occurs.

116. GINGIVAL FIBERS
 These are of 5 groups which collectively form
GINGIVAL LIGAMENT.
 These are largely composed of collagenous
fibers.

117. (A)
Alveologingival
Extends from the bone of
alveolar crest to gingival
margin.
(C) Circular
Forms a band around the tooth.
Encircles the tooth in a ring like
fashion.
Binds free gingiva to the tooth
(B) Dentogingival
Also called GINGIVODENTAL.
Extends from cervical cementum
to CT of free and attached gingiva.

119. STIPPLING OF GINGIVA
 Gingiva is characterised by stippled surface.
 It refers to the surface texture (i.e like an orange
peel)
 Its normal physiological appearance ,absence
/reduction of which shows diseased gingiva.
 Its produced by an elongated papillary layer of
connective tissue which give rounded protuberance
to the gingiva.

120.  Attached gingiva-stippled
 Marginal gingiva –not stippled
 Stippling is not very prominent
on lingual side than on labial .
 Its less or absent in infancy &
old age
 Males tends to have more
heavily stippled gingiva.

122. VERMILION BORDER OF LIP
 It’s a transitional area between the skin of lip
& mucous membrane of oral cavity.
 Area is pink or red in colour due to the thin
epithelium & high vascularity because the
papillae of lamina propria are long , blood
vessels are very near to epithelial surface
giving it red color.
 Here keratinization ends.
 Occasionally contains sebaceous glands.
 It lacks salivary gland.

123.  Between the vermilion border of lip & the
thicker non keratinized labial mucosa is an
intermediate zone covered by
parakeratinized oral epithelium
 In infants this area is thickened as an
adaptation to suckling called SUCKLING
PAD.

124. MUCOSA OF SOFT PALATE
 Is thin non keratinized statified squamous
epithelium with taste buds.
 Lamina propria is thick & highly vascularied,red
in colour.
 Elastic fibers are rich in this layer.
 Submucosa is loose & contains continuous
layer
of mucous glands, taste buds & minor salivary
gland .

125. VENTRAL SURFACE OF TONGUE
 Epithelium of this surface is thin, non –
keratinized & loosely textured.
 Lamina propria is thick ,having short papilla
with rich capillary network.
 Due to loose texture of the mucosa its
loosely attached to underlying structure so
the tongue is freely mobile.

127. FLOOR OF THE ORAL CAVITY
 Its covered by stratified
squamous, non-
keratinized epithelium
that has a pink color.
 Its thin & loosely
adherent to the
underlying structure
which allows free
mobility to tongue.

128. LIP
o The outer skin is covered by
epidermis, a stratified
squamous keratinized
epithelium.
o The vermillion zone, or red
area of the lip, is covered by
a stratified squamous
keratinized epithelium but
has no sweat glands or oil
glands.
A: Skin
B: Vermillion zone
C: Oral (labial) mucosa
D: Minor salivary glands

129. o The junction between the outer skin and
the vermillion zone is known as the
vermillion border .
o The internal side of the lip is covered by
stratified, non-squamous and non-
keratinized epithelium overlying a dense
collagenous connective tissue .
o The lips, which are designed to have
maximum flexibility, are tied to the
alveolar mucosa via a thin labial frenum
that consists of sickle shaped folds of
connective tissue

130. CHEEK
 The cheeks consist of
an outer skin side and
an inner vestibular
side that faces the
teeth and tongue.
 Buccinator muscle
forms the major
portion of cheek

131.  The vestibular side is lined
by stratified, non-
keratinized epithelium
covering a dense irregular
collagenous connective
tissue that contains minor
salivary glands and
sebaceous glands known
as Fordyce's granules or
spots.
 These spots are yellowish-
white in color, especially in
the area where the upper
and lower teeth meet

132. SPECIALIZED MUCOSA [TONGUE]
 Dorsal surface of tongue is covered by
specialized mucosa.
 It’s non keratinized.
 Containing numerous papilla having taste buds.
 Anterior 2/3rd supplied by TRIGEMINAL NERVE
through its lingual branch.
 Posterior 1/3rd supplied by
GLOSSOPHARYNGEAL NERVE.

134. DIVISION OF TONGUE
BOTH THE PARTS ARE SEPARATED BY ‘V’
SHAPED FURROW K/A SULCUS
TERMINALIS
ANTERIOR PART:-
 Also k/a PAPILLARY
PART.(ant 2/3rd)
 Contain many fine
,pointed,cone shaped
papillae which gives velvety
appearence
POSTERIOR PART:-
 Also called LYMPHATIC
PART
 It faces posteriorly(1/3rd)

135. PAPILLAE OF TONGUE

136. FILIFORM PAPILLAE
The smallest and most
numerous found in
humans.
 They are conical,
elongated projections
of CT covered with
highly keratinized
stratified squamous
epithelium.
Filiform papillae DO
NOT contain taste

138.  They are distributed
over the entire
anterior surface of the
dorsum of the tongue.
The tips of the filiform
papillae point
posteriorly.
 These papillae
appear to form rows
that diverge laterally
from the midline and
parallel the arms of
the SULCUS
TERMINALIS.
FUNGIFORM
PAPILLAE
FILIFORM
PAPILLAE
FOLIATE
PAPILLA
E
CIRCUMVALLATE
PAPILLAE

139. FUNGIFORM PAPILLAE
 Found chiefly at the side
& tip of tongue ,scattered
between filiform papillae.
 Are round, elevated ,red
& mushroom-shaped
(narrow stalk and a
smooth-surfaced, dilated
upper part)
 The word Fungiform is
taken from fungus like.
 They’re 150-400 in µm in
diameter.

140.  Their colour is derived
from a rich capillary
network visible through
thin epithelium.
 They may or may not be
keratinized
 Have vascular core of
lamina propria
 1-3 Taste buds are
present in the stratified
squamous epithelium on
the dorsal surface of these
TASTE BUD

141. FOLIATE PAPILLAE
They occur on the
posterolateral surfaces of
the tongue as 4-10
vertical folds)
They are poorly
developed in humans
(frequently seen in
mammals)though they are
recognized more easily in
younger individuals.

142. These are raised ,round to oval follicles
with lymphoid aggregate in the center.
Lined by stratified squamous epithelium.
These papillae contain many taste buds in
the epithelium of the facing walls of
neighboring papillae.

143. Serous glands
Dorsal
TB
ducts
FOLIATE PAPILLAE

144. CIRCUMVALLATE PAPILLAE
 The human tongue has 8
to 12 of these
papillae.These are the
extremely large, dome-
shaped structures that
reside in the mucosa just
anterior to the sulcus
terminalis.
 lined with stratified
squamous epithelium that
contains numerous taste
buds.

145. Taste bud (chemoreceptor)
Salt, sweet, sour, bitter
Non-keratinized SSE
Taste pore
Circumvallate Pallilae

146.  Ducts of minor
salivary glands (von
Ebner’s glands)
opens into deep
circular furrow ,their
serous secretions
serve to wash out the
soluble element of
food & main source
of salivary lipase.
TASTE
BUDS
Serous
glands
CV
FUNGIFORM
PAPILLAE

147. TASTE BUD
 These are also k/a
GUSTATORY CALICULI
(SMALL CUP SHAPED
STRUCTURE)
 These are made up of
modified epithelial cells
arranged in groups.
 These are found in
tongue,soft
palate,epiglottis &
posterior wall of oral part
of pharynx.but most
numerous on
circumvallate papillae of

148.  More in no in infants than in adults
 These are ovoid, barrel-shaped intra-
epithelial structures about (80microns
high & 40 microns thick) and are
associated with tongue papillae except
filiform type.
 The outer surface of the taste bud
covered by flat epithelial cells (covers
gustatory pore of taste bud)

149.  The gustatory pore leads to a small
canal i.e lined by supporting cells of
taste buds
 Outer supporting cells are like staves of
a barrel.
 Inner supporting cells are spindle
shaped.
 The taste receptor or neuroepithelial
cells are receptors of the taste
stimuli.(found between the inner
supporting cells).
 These receptor cells have finger like

150.  Base of each taste bud is penetrated by a
group of gustatory nerve fibers.
 Substance to be tasted ,dissolves in saliva &
enters in taste bud, tasted by neuroepithelial
cells & stimuli is taken by a rich plexus of
nerves found below the taste bud.

151. REGIONS OF DISTRIBUTION OF TASTE
4 taste sensations:
 Sweet
 Salty
 Sour and
 Bitter

152.  Sweet :Tip of the tongue.
 Salty:-lateral borders of
tongue.(mediated by
intermediofacial nerve by
chorda tympani)
 Bitter & Sour:-( mediated
through glossopharyngeal
nerve) palate & posterior
part of tongue.
 Bitter in middle
 Sour in posterolateral part
of tongue.

153. LINGUAL TONSIL
 The lingual follicles are
round or oval-shaped
organs located at the
back of the tongue
behind the foramen
cecum and the sulcus
terminalis in the
mucous membrane
covering the tongue.
 The lingual crypts is
lined with stratified
squamous epithelium.

154.  They enlarge gradually from birth to about
seven years of age and then shrinks. Each
oval consists of a large number of lymphoid
follicles. The lingual tonsils are part of the
lymphatic system and are important to the
body's defense against infection. They are
composed of lymphoid tissue, which contains
germ-killing cells. The tonsils help protect
against upper respiratory tract infection.

155. NON KERATINOCYTES
Other epithelial cells seen in epithelium called
clear cells have a clear halo around the nuclei.
These are –
1. MELANOCYTES
2. LANGER HAN’S CELLS
3. MERKLE’S CELL &
4. INFLAMMATORY CELLS
 are about 10% of epithelium cells.
 No desmosomes except merkel’s cells & few
tonofilaments.
 Do not participate in maturation. so called as
non keratinocytes.


157. MELANOCYTES
 specialized pigment cells whiich produce melanin.
 seen in basal layers.
 Arise from neural crest & enter the epithelium at about 4
thweek of intra uterine life.
 no desmosomes & tonofilaments.
 But posses long dendritic processes extending b/w
keratinocytes.
 produce melanin as small, dense,structures called
melanosomes

160. .
-- Same number of melanocytes in both light & darkly
pigmented individuals but difference is from the
activity of these cells in production of melanin.
-- Sometime seen in connective tissue & the melanin is
engulfed by macrophages called as melanophages.

161.  Seen in gingiva,buccal mucosa, hard palate
& tongue

162. LANGERHAN’S CELLS
- Dendritic cell mainly seen suprabasally.
- No desmosomes, tonofilaments.
- Derived from ‘’bone marrow’’
- These are called ‘’high level clear cell’’
- Small rod or flask shaped granules called as
‘’birbeck granules’’

164. LANGERHAN’S CELLS
- Function-immunologic, processing
&recognizing the antigen, so AP cell
- Can migrate to regional lymph nodes

165. MERKEL’S CELLS
-Seen in basal layer.
-Not a dendritic cell.
-No tonofilaments & occasional desmosomes.
-Origin-neural crest derivative. arises from keratocytes.
-E/M-small, dense membrane bound vesicles in the
cytoplasm close to a nerve fiber.
-Function-liberate neuro- transmitter substance & trigger
impulses.
-Sensory & tactile function.
-Staining-PAS +ve.

167. INFLAMATORY CELLS
-Normally seen, variable in position.
-Transient cells.
-Common are lymphocytes, even PMN’S & mast
cells also seen.
-Lymphocytes are associated with Langerhan’s
cells& to activate T-lymphocytes.
-Round cells with central nuclei.

169. JUNCTIONS IN ORAL MUCOSA
Dentogingival (interface between gingiva & tooth)
Mucogingival (between gingiva & alveolar mucosa)
Mucocutaneous (between skin and mucosa)
3 junctions are present :-
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Oral Mucosa

170. MUCOCUTANEOUS JUNCTION
It’s a junction between skin &
mucosa
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177
Oral Mucosa

171. VERMILION BORDER OF LIP
 It’s a transitional area between the skin of lip
& mucous membrane of oral cavity.
 Area is pink or red in colour due to the thin
epithelium & high vascularity because the
papillae of lamina propria are long , blood
vessels are very near to epithelial surface
giving it red color.
 Here keratinization ends.
 Occasionally contains sebaceous glands.
 It lacks salivary gland.

172. MUCOGINGIVAL JUNCTION
 Junction between gingiva &
alveolar mucosa
 Clinically identified by
change of color from bright
pink –paler pink, also by
stippling of gingiva
 Histologically identified by
type of epithelium -which is
either keratinized or
parakeratinized &
composition of lamina
propria -numerous collagen
bundles.
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Oral Mucosa

174.  Coronal to
mucogingival junction
clinically visible
depression in gingiva
k/a free gingival groove-
whose level
corresponds to the
bottom of gingival
sulcus.
 It demarcates free
/attached gingiva.
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181
Oral Mucosa

175. DENTOGINGIVAL JUNCTION AND JUNCTIONAL
JUNCTIONAL EPITHELIUM
 Dentogingival junction is
the region where the oral
mucosa meets the surface
of the tooth .
 Formed by junctional
epithelium & gingival
fibers & together
considered as a functional
unit called :-
DENTOGINGIVAL UNIT.
 ITS A POINT OF
REDUCED RESISTANCE
TO MECHANICAL
FORCES & BACTERIAL

176. The gingiva consist of 2 important
tissues that helps to maintain the
junction intact.
The lamina Propria The gingival
epithelium
Is dense, resilient,
withstands forces
during mastication
•The integrity of dentogingival junction is
maintained by both (epithelium & connective
tissue
Its keratinized or
parakeratinized.

177. THE INTEGRITY OF DENTOGINGIVAL JUNCTION
IS MAINTAINED BY BOTH (EPITHELIUM &
CONNECTIVE TISSUE
When the epithelium
is injured ,mitotic
capacity & migratory
capabilities of cells
helps to repair this
injury.
when the connective
tissue is injured
,ribosomes present
with in the fibroblast
form procollagen &
ground substance
which helps in repair.

178.  Firmness of the junction is maintained by
gingival portion of PERIODONTAL
LIGAMENT.
 Defense mechanism of the body helps in
defense against bacterial injury.
 The lysosomes of junctional epithelium may
have phagocytic function.

179. GINGIVAL SULCUS
 It’s a small pocket
that extends from
free gingival margin
to dentogingival
junction.
 Its depth in healthy
gingiva is at
approximate level of
free gingival groove
on outer surface of

180. PERIODONTAL POCKET

181. SULCULAR EPITHELIUM
 It’s the epithelium lining the gingival sulcus
extending from coronal limit of junctional
epithelium to the crest of gingival margin.
 It lacks rete peg.
 It is the non-keratinized or parakeratinized,
thin, stratified, squamous epithelium, the
junction between the epithelium & lamina
propria is smooth & straight.
 Its semi permeable & allows passage of toxin
from gingiva into sulcus.

183. JUNCTIONAL EPITHELIUM
 The epithelium that is
attached to the tooth
surface (enamel or
sometimes cementum)
continuous with sulcular
epithelium.
 Derived from reduced
enamel epithelium of the
tooth germ.

186. JUNCTIONAL EPITHELIUM IS DIVIDED INTO 3
ZONES
CORONAL-highly semipermeable,
allows entry of toxins & passage of
gingival fluid into sulcus
MIDDLE-an adhesive zone
APICAL-having proliferative capacity
to replace shedded
cells of junctional epithelium

187. PRIMARY ATTACHMENT EPITHELIUM
 Attachment of junctional epithelium onto tooth surface is called
ATTACHMENT EPITHELIUM.
 During eruption tip of tooth approaches the oral mucosa because
of which the reduced enamel epithelium & oral epithelium meet
& fuses.
 The remnant of primary enamel cuticle is called
NYSMYTH’S MEMBRANE.
 The epithelium covering the tip of crown degenerates from its
center & crown emerges through this perforation.
 Reduced enamel epithelium remain & its called primary
attachment epithelium once tip of crown emerges.

188.  With eruption of tooth the reduced enamel
epithelium moves apically, reducing its lenght
,eventually a shallow groove develops
between gingiva & surface of tooth k/a
gingival sulcus,which extends around
circumference of tooth which is bordered by
attachment epithelium at its base & laterally
by free gingival margin.

189. SHIFTING OF DENTOGINGIVAL JUNCTION
 Dento gingival junction - the region where the
tooth is attached to gingiva & its formed as tooth
erupts into oral cavity.
 Almost entire enamel is covered by epithelium
when tip of enamel first emerges through the
mucous membrane (eruption continues until it
reaches plane of occlusion & by that time 1/3rd-
1/4th of enamel is still covered by gingiva)
 As crown continues to grow attachment
epithelium separates from enamel gradually

190. ACTIVE ERUPTION PASSIVE ERUPTION
Its the actual
movement of
teeth toward the
occlusal plane
It’s the separation of
primary attachment
epithelium from
enamel surface

192. SECONDARY ATTACHMENT EPITHELIUM
When the reduced enamel
epithelium has disappeared
,the primary enamel
epithelium by is replaced
secondary attachment
epithelium derived from
gingival epithelium.

193. APICAL SHIFT OF GINGIVAL SULCUS
 Crown exposure ,which involves passive
eruption & further recession is described in 4
stages:-

195. STAGE I :-
It’s a physiological stage
Present upto 1 year before shedding in primary & for
upto 20-30 yrs of age in permanent dentition.
In this stage this stage the bottom of gingival sulcus
remain on anatomical crown i.e on enamel portion &
apical end the attachment of epithelium lies at CEJ

196. STAGE II :-
Its also physiological stage
Usually present upto age of 40 yrs.
In this bottom of gingival sulcus lies on enamel but
apical end of attachment epithelium has shifted from
CEJ to cementum

197. STAGE III:-
Anatomical crown is fully exposed in oral cavity.
the bottom of gingval sulcus shifts to CEJ .
Epithelium attachment also shifts on cementum.
This is NOT a passive manifestation.
The epithelium keeps on shifting along tooth surface &
no longer remains at CEJ.

198. STAGE IV:- (GINGIVAL RECESSION)
RECESSION:-is defined as an exposure of root surface by an
apical shift in the position of gingiva.
its a result of pathology. That may be inflammatory or non –
inflammatory
In this stage both (sulcus & epithelial attachment) are on
cementum.
This condition doesn't show any definite time of its occurrence
,it depends upon health of gingiva. but once it occurs it
increases with age.

199. ANATOMIC CROWN CLINICAL CROWN
A. DURING THE FIRST 2 STAGES :-CLINICAL CROWN IS
SMALLER THAN ANATOMIC CROWN.
B. IN 3RD :-STAGE CLINICAL CROWN IS = TO ANATOMIC CROWN
C. DURING 4TH STAGE:-CLINICAL CROWN IS LARGER THAN
ANATOMIC CROWN (AS THE ROOT PART IS EXPOSED)
Portion of the tooth
which is covered
with enamel.
Portion of tooth which is
exposed in oral cavity.
It may be smaller/equal/larger
than anatomic crown depend
upon position of gingiva on
tooth surface.

200. ACTUAL POSITION APPARENT POSITION
OF GINGIVA
Its at level of
epithelial
attachment on
tooth
It determines
severity of
recession.
It’s the level of
crest of
gingival margin

201. SULCUS & CUTICLES
An organic attachment called EPITHELIAL
ATTACHMENT ,which is present between the
epithelium & tooth.
This mechanism is given by ORBAN & GOTTLIEB.
It involves primary cuticle forming an organic union
between ameloblast & enamel.
When oral epithelium replaces the ameloblast
secondary cuticle is formed.

202. When epithelium proliferates
beyond the CEJ ,cuticle extends
along cementum.
CEMENTAL CUTICLE &
SECONDARY ENAMEL
CUTICLE ARE CALLED AS
DENTAL CUTICLE.

203. DEEPENING OF SULCUS (POCKET FORMATION)
As tip of crown emerges through oral mucosa the gingival
sulcus forms.
Separation of reduced enamel epithelium from actively
erupting tooth causes deepening of sulcus.
Initially after eruption of crown tip ,epithelium separates
rapidly from tooth surface, later when it occludes the
separation of attachment from tooth surface slows down.

204. Under normal conditions ,sulcus depth differs ;4
5 % of all measured sulci are below 0.5 mm.
Average sulcus =1.8 mm
Lymphcytes, plasma cells & langerhans cells
are seen in infected or inflamed sulcular & oral
epithelium, which produce defense reaction to
bacteria

205. ATTACHMENT EPITHELIUM
EPITHELIUM ATTACHMENT IS SUBMICROSCOPIC ( 4 0 NM WIDE)
CELLS OF ATTACHMENT EPITHELIUM ARE HELD TO THIS BY
HEMIDESMOSOMES.
PRIMARY ATTACHMENT
EPITHELIUM:-
Is attachment of ameloblast
to tooth, is a basal lamina
to which hemidesmosomes
are attached.
SECONDARY ATTACHMENT
EPITHELIUM :-
Composed of cells derived
from oral epithelium ,forms an
epithelial attachment same as
primary epithelium i.e basal
lamina & hemidesmosomes.

206. MIGRATION OF THE ATTACHMENT EPITHELIUM
As cells leave stratum germinativium,they become
specialized.
In attachment epithelium the cells specialize & synthesize a
basal lamina, then they migrate over it, with hemidesmosomal
attachment.
A CELL ONCE SPECIALIZED DOESN’T SYNTHESIZE DNA
& DOESN’T DIVIDE.
The time taken for labeled attachment epithelial cells to
migrate & desqumate is called TRANSIT TIME (in humans its
72-120 hours)

207. POSSIBILITIES WHICH CAUSE SULCUS TO MOVE
APICALLY
Toxic or inflammatory influence affect the
basal cells. This diminishes the ability of
basal cells to synthesize DNA.
Collagenolysis occurs which destroy collagen
fiber.
Immunologically competent cells produce tissue
damage

208. how the oral mucosa
differs from skin? ?
1) Color
2) Moist surface
3) Absence of adnexal skin structures such as hair follicles, sweat glands
and sebaceous glands (exception in Fordyce’s disease)
4) Fordyce’s disease: Sebaceous glands in oral cavity predominantly in
upper lip, buccal mucosa and alveolar mucosa
5) Presence of minor salivary glands in oral mucosa
66) exture of surface: Oral mucosa is smoother than the skin (few
exceptions like dorsal tongue –due to papillae; hard palate –rugae;
gingiva –stippling)
7) Firmness: Oral mucosa varies in its firmness. For example buccal
mucosa and lips are loose whereas the gingiva and hard palate are firm

209. DEVELOPMENT OF ORAL MUCOSA
 Its initiated by rupture of buccopharyngeal
membrane at about 26days in utero. With this
fusion of embryonic stomatodeum & foregut
takes place & entire stomatodeum is lined by
epithelium (derived by ectoderm & endoderm)
 The single layer lining changes to double layer
in 5-6 week of intrauterine life.
 Epithelium of dental lamina vestibule region
divides rapidly & thickens by 8-9 weeks.
 8-11 weeks palatal selves rise & close which
establish future morphology of adult oral cavity


210.  By 10-14 weeks –thickened epithelium of
dental lamina shows central cellular
degeneration which cause separation of cells
of cheek & alveolar mucous-forms ORAL
VESTIBULE.
 At around 7TH week lingual mucosa forms &
develop circumvallate & foliate papillae
 At around 10th week filiform papillae
develops

211.  Between 10-12 weeks cells of masticatory &
lining mucosa show division ,stratification &
thickening.(keratinized area –hard palate
,alveolar ridges of gingiva contain darkly
stained columnar cells.
 The epithelium that forms areas of lining
mucosa retains cuboidal basal cells.
 Between 13-20 weeks epithelium is fully
developed & show distinct layers .

212.  There is development of keratohyline
granules ,merkel cells & langerhans cells.
 Oral epithelium shows parakeratinization it
becomes orthokeratinized after birth with
eruption of teeth.

213. AGE CHANGES
 As age increases mucosa turns to be smoother
 Dryer {atrophic / friable}
 These changes represent the cumulative effects
of {a} systemic disease
{b} drug therapy
HISTOLOGICALLY:-
The epithelium appears thinner

214. REFERENCES
 Oral development & histology
3rd edition
James K Avery