The document discusses the histology of oral mucosa and gingiva. It describes the epithelium, lamina propria, submucosa, and organization of oral mucosa. The epithelium can be keratinized or non-keratinized. Gingiva specifically surrounds the teeth and consists of free gingiva, attached gingiva, and interdental papillae. The document provides detailed information on the structure and layers of oral mucosa and gingiva.
The POPPY STUDY (Preconception to post-partum cardiovascular function in prim...
Histology of oral mucous membrane and gingiva
1. HISTOLOGY OF ORAL MUCOUS
MEMBRANE AND GINGIVA
Vinay Pavan Kumar .K
1st year MDS
AECS Maaruti College of Dental Sciences
2. HISTOLOGY OF ORAL MUCOUS
MEMBRANE AND GINGIVA
Definition
Functions Classification
Structure
Organization
Histology of
gingiva
Prosthetic
consideration
Biological width
3. The oral cavity is in many respects a very
interesting part of the human body .
Many different kind of tissue from the hardest
teeth to the softest, the salivary glands are
found therein.
The oral cavity is lined with an uninterrupted
mucosa which is continuous with the skin near
vermillion border of the lips and with the
pharyngeal mucosa in the region of soft palate
INTRODUCTION
4. Functions of oral mucosa
Protection :
Barrier for mechanical trauma and
microbiological insults
Sensation :
Temperature (heat and cold), touch, pain,
Reflexes such as swallowing, gagging and
salivation
Absorption :
Nitrates are absorbed sublingually
5. Secretion:
Salivary secretion creates a moist oral
cavity helps in speech, swallowing,
mastication and in the perception of taste.
Thermal regulation:
Important in dogs not in humans
Excretion:
excretion of certain metabolites
Esthetics :
Lips and gingiva enhance facial esthetics
6. Classification of oral mucosa
Based upon primary function served
1. Masticatory Mucosa (25%)
2. Lining Mucosa (Covers 60% of total area)
3. Specialised Mucosa (15%)
Based upon keratinisation
1. Keratinised
Orthokeratinized
Parakeratinized
2. Non-keratinised.
9. Epithelium
Epithelium of the oral mucosa is stratified squamous
epithelium.
It may be
1.Keratinized
2.Non keratinized
Keratinized layer
ortho keratinized
Para keratinized
10. Oral epithelium
Consists of two populations of cells:
Progenitor population
Maturing population
Progenitor cells function is to divide and
provide new cells
Maturing cells continually undergo a
process of differentiation or maturation to
form a protective layer
12. Turn over time
Skin : 52 – 75 days
Gut : 4 – 14 days
Gingiva : 41 – 57 days
Cheek : 25 days
Junctional Epithelium : 5 - 6 days
The time taken for a proginetor cell to pass through
the entire epithelial thickness and reach the surface
16. Basal layer made of cell that synthesize DNA &
undergo mitosis.
Stratum Basale
Basal cells show ribosomes & elements of rough
endoplasmic reticulum indicative of protein
synthesizing activity.
17. Structureless zone seen under
light microscope is basement
membrane.
1 – 4 microns wide.
Under electron microscope,
Basal lamina
lamina lucida – light zone
lamina densa – dark
zone
18. Basal cells are attached to basal lamina by
hemidesmosomes.
Epithelial cell-cell contact is made through
desmosomes - macula adherens. These are
anchored intracellularly by tonofibrils.
19. i) Serrated- heavily packed with tonofilaments
which are adaptations for attachment.
ii) Non-serrated – stem cells – slowly dividing
cells which serve to protect genetic information of
the tissue.
20. Stratum spinosum or prickle cell
layer:
It is a layer of relatively large irregular polyhedral
cells.
Show first sign of maturation.
Nuclei stains less intense the intercellular spaces of
the prickle layer are large and distended, with more
prominent desmosomes
22. Active in protein synthesis.
Involucrin - soluble precursor protein of the
cornified envelope appears first in the spinosum.
Protein synthesis rate progressively gets
diminished as cell approaches stratum corneum.
In the upper part cells of stratum granulosum,
shows granules called ODLAND BODIES.
23. Keratinosome or odland bodies or
membrane containing granules
Modified lysosomes
0.25µm in length.
Rich in phospholipids.
Structure - layers of parallel lamellae, probably
originating from golgi apparatus.
Lamellar granules discharge their contents -
permeability barrier.
24. Stratum corneum
Made up of keratinised squamae, which are
larger & flatter than the granular cells.
Nuclei & other organelles disappear.
25. Cell surfaces in this layer are more regular &
more closely adapted to adjacent cell surfaces.
The filaggrin a non fibrous inter-filamentous
matrix protien helps in this close adaptation.
26. Types of keratinized epithelium
Parakeratinized Epithelium :The superficial cells
are dead but retain the nucleus
Orthokeratinized Epithelium : The nuclei are lost
in epithelium
27.
28. Non – keratinized epithelium
Nonkeratinized epithelial cells in the superfacial
layers do not have keratin filaments in the cytoplasm
The surface cells also have nuclei
This epithelium is associated with lining of the oral
cavity
29. Difference
Keratinized
Layers - basal, spinosum,
granular, cornified layer.
Produce a cornified
surface layer.
Prickly appearance.
Nonkeratinized
Layers-basal,intermediate,
surface layer.
Do not produce a cornified
surface layer.
Intercellular spaces not
obvious-no prickly
appearance.
30. No nuclei-orthokeratinised
Pyknotic nuclei-
parakeratinised
Filaggrin present.
Numerous
tonofilaments,keratohyaline
granules present.
Lack filaggrin,but contain
involucrin.
Less developed and
dispersed tonofilments,lack
keratohyaline granules.
Stratum superficiale
contains nucleated cells
31. Lamina Propria
Two Layers
Papillary layer
Close to epithelial ridges.
Arranged loosely.
Reticular layer
Parallel to epithelium.
Fibers are very thick.
Consists of cells , blood vessels, neural elements &
fibers embedded in amorphous ground substance.
32. Cells found in lamina propria
Fibroblast
Histiocytes
Macrophages
Mast cell
Polymorph nuclear leucocytes
Lymphocytes
Plasma cells
Endothelial cells
33. Submucosa
It attaches the mucous
membrane to the
underlying structures –
muscle or bone
loose or a firm attachment
and consists of glands,
blood vessels, nerves, &
adipose tissues.
connective tissue of
various thickness
35. Organization of the Oral Mucosa
3 types according to function:
Masticatory Mucosa:25% of total mucosa.
Lining Mucosa:60% of total mucosa
Specialized Mucosa:15% of total mucosa.
36. Lining mucosa
Covers the floor of mouth, ventral (underside)
tongue, alveolar mucosa, cheeks, lips and soft
palate.
Lip
Lip is covered by lining mucosa
41. Mucosa of the Tongue - Specialised
mucosa
Anatomical division
It is divided into two parts by a V-shaped groove
known as sulcus terminalis.
Anterior 2/3rd or papillary portion or body of the
tongue contains lingual papillae.
Posterior 1/3rd is lymphatic portion or base of the
tongue contains lingual tonsil.
42. The different papillae found on the dorsal surface of
the tongue are:
1. Filliform papillae
2. Fungiform papillae
3. Circumvallate papillae
4. Foliate papillae
43. 1. Filliform papillae
Pointed extensions of the
keratinized epithelial cells
Most numerous papillae of the
tongue
Not associated with taste buds
Scanning electron micrograph
of Filliform papillae(arrow)
44. 2. Fungiform papillae
Fewer than the filliform papillae and are scattered
over the dorsal surface of the tongue
Rounded elevations above the surface of the tongue
Have taste buds on their superior surfaces
Not keratinized
45.
46. 3. Circumvallate papillae
Located at the junction of the anterior two thirds (body)
and posterior one thirds (base) of the tongue
There are eight to twelve in number
Lined with taste buds and also openings of serous
glands
The secretion from the serous glands washes away
food for renewal of taste
47.
48. 4. Foliate papillae
Located in the furrows along the posterior sides of
the tongue
Lined with taste buds
Not prominent in human beings
49. Taste Buds
They are small ovoid barrel shaped organs
40 micron thick and 80 micron high
Their outer surface is covered by flat cells
which surround a small opening called the Taste
Pore
50. Areolar mucosa
The areolar mucosa is a reddish-pink
tissue with blue vascular areas.
The epithelium is extremely thin non-
keratinized mucosa with a lamina propria
51. Hard Palate
Covered by masticatory mucosa
lateral regions of the posterior part contains
palatine glands
52. Gingiva
Covers the alveolar process of jaws and
surrounds the cervical portion of teeth.
It develops from the union of oral epithelium and
reduced enamel epithelium
Gingiva can be classified as
Free gingiva,
Attached gingiva and
Interdental papilla
53. Part of the oral mucosa
that surrounds the necks
of the teeth and forms the
free margin of the gingival
tissue
differentiated apically by
the free gingival groove
Free gingiva (marginal gingiva)
54. Attached gingiva
Between the free gingival groove and the
alveolar mucosa
The junction of the attached gingiva and the
alveolar mucosa is called mucogingival junction
In healthy mouth attached gingiva shows
stippling
56. Gingival sulcus
Space or potential space between the tooth
surface and the free gingiva.
It is lined with sulcular epithelium
Extends from free gingival margin to the
junctional epithelium.
57. Junctional epithelium
Forms the seal of the gingival epithelium and the
tooth
Floor of the gingival sulcus and extends apically
to the enamel of the tooth
Disturbances of epithelial attachment results in
deepening of the sulcus which is a sign of
gingival/periodontal disease
58. Sulcular epithelium
It is nonkeratinized.
No rete pegs in sulcular epithelium.
Sulcular epithelium is continuous With gingival
epithelium & the attachment epithelium
59. Gingiva contains dense fibers of
collagen:
Dentogingival : extends from the
cervical cementum into the lamina
propria of the gingiva.
Circular: small group of fibers
that circle the tooth & interlace
with other fibers.
60. Dentoperiosteal: fibers
can be followed from the
cementum into periosteum
of the alveolar crest & of
the buccal & palatal or
lingual surface of the
alveolar bone.
Alveologingival: fibers
arise from the alveolar
crest & extends into lamina
propria.
62. Biologic width
The dimension of space that the healthy gingival
tissues occupy above the alveolar bone is the
biologic width.
Connective Tissue attachment + junctional
epithelium constitutes Biologic width
1.07mm +0.97mm= 2.04 mm
Any restoration should be atleast 3mm above
the alveolar crest to prevent the violation of the
biologic width.
64. Effect Of Aging On The Oral
Mucosa
Epithelial thinning
Decreased keratinization
Less prominent rete pegs
Decreased cellular proliferation
Loss of submucosal elastin and fat
Increased fibrotic connective tissue with
degenerative alteration in the collagen.
66. Behaviour of oral mucosa under
stress
Under compression behaves in a viscoelastic fashion.
Loaded epithelium demonstrates decrease in the
depth of epithelial ridges & connective tissue papillae
Care to be taken during impression procedures by
applying minimal pressures.
67. Tissue response
A. Recently made dentures:
Inflammation .
Soft tissue distortion.
Impingement of gingival margin.
Accumulation of dental plaque.
B. Dentures in use for > 1 year
Hyperkeratosis.
Scarring of tissue in border area.
Gross tissue distortion.
68. Soft tissue changes in oral mucosa
due to prostheses
soft tissue hyperplasia
fibrous hyperplasia.
epulis fissurata.
papillary hyperplasia.
inflammatory process under denture bases
denture stomatitis.
Candidiasis.
ulcerative lesions
angular chelitis.
69. Soft tissue hyperplasia
Rolls of hyperplastic tissues under denture
base
Due to bone resorption, with lesion filling the
space under denture base.
Develops slowly, painless.
Surgical removal.
New dentures.
70. Papillary hyperplasia
Granular type of inflammation
seen in palatal region.
Numerous papillary projections
give a warty appearance.
They show precancerous
tendencies.
Discontinue denture wearing.
Surgery.
New dentures
71. Epulis Fissuratum
It is a pathologic condition that
appears in the mouth as an
overgrowth of fibrous connective
tissue.
Also known as inflammatory
fibrous hyperplasia, denture
epulis and denture induced
fibrous hyperplasia.
It is mainly caused due to ill
fitting dentures
74. Angular chelitis
SIGNS
Bilateral lesion that develops at the angle of
the lips.
Deep fissure or crack may be seen.
Appear ulcerated.
Exudatve crust may be present.
Anti fungal therapy.
75. Denture bearing area
Points to be considered while fabrication of
denture:
Selective placement of forces by denture
base on supporting tissues.
Form and placement of denture borders to
accommodate normal function.
76. Selective placement of force can be achieved by
employing different impression techniques
depending on the patients oral condition
Minimal pressure technique/Mucostatic
technique .
Selective pressure technique.
Pressure / Muco-compressive technique.
77. Crest of the residual ridge
(maxillary)
Firmly attached to the bone.
Keratinized epithelium.
Dense collagen fibers .
Sub mucosa – fat or glandular
cells.
Primary support for denture.
78. Palatine rugae
Irregularly shaped rolls of soft
tissue in the anterior part of
hard palate.
Clinical considerations
Secondary stress bearing area.
Resists forward movement of denture.
Tissue rebound phenomenon.
Maxillary major connector should end into
depressions between the rugae.
79. Mucous membrane of hamular notch
Space between the posterior part of
the maxillary tuberosity & pterygoid
hamulus.
It is thick and made of loose areolar
tissue.
Marks the distal end of
denture.
80. Buccal shelf area
Partially keratinized.
Loosely attached.
Bone – compact bone.
Clinical implication
Impression should cover
the entire available area.
81. Slope of the residual ridge
(mandibular)
Keratinized epithelium .
When the soft tissue is
movable in the crest of the
ridge ,impression should be
recorded in its resting position.
82. F.P.D & oral mucosa
Sub gingival finish
esthetics.
old restoration extending into the
intracrevicular space.
Insufficient vertical length or height
Margins should be smooth with proper
fit.
84. Implants and Biological width
It has been found that the biological
width need not be a vertical
dimension but can have a horizontal
component.
Platform switching provides this
horizontal distance and so preserves
the crestal bone.