Upload By : Ahmed Ali Abbas
Babylon University College of Dentistry
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Oral histology
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Oral mucous membrane
1. Oral Mucous Membrane
UploadUpload By : Ahmed Ali AbbasBy : Ahmed Ali Abbas
Babylon University College of DentistryBabylon University College of Dentistry
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2. 1.Oral Mucosa
The moist lining of the oral cavity is called Oral
Mucosa or Oral Mucous Membrane
The function of oral mucosa is protection,
sensation and secretion
It is continuous with the skin outside the oral
cavity and differs from it in appearance and
structure
6. Oral Epithelium
Oral epithelium forms the surface of the oral mucosa
that forms a barrier between the oral environment
and the deeper tissues
It is derived from the embryonic ectoderm
It is stratified squamous epithelium and may or may
not be keratinized
Beneath the epithelium lies the connective tissue
10. Keratinized oral epithelium
Most of theoral mucosal surfaceislined by nonkeratinized stratified
squamous epithelium except gingiva, hard palate and dorsal surface
of thetonguewheretheepithelium iskeratinized
The keratinized cells have no nuclei and the cytoplasm is displaced
by largenumbersof keratin filaments
Keratinized epithelium is associated with masticatory function and
havefour layersof cells
12. 1. Stratum Basale
The cells of the stratum basale are cuboidal or low columnar and
form asinglelayer resting on thebasal lamina
The basal lamina is at the interface of the epithelium and lamina
propria
Epithelial cellsof theoral mucosaarein aconstant stateof renewal
Thebasal cellsshow themaximum mitotic activity
13. 2. Stratum Spinosum
Stratum spinosum isusually several cellsthick
They shaped likepolyhedron with short cytoplasmic processes
The stratum basale and the first layers of stratum spinosum are
referred to as stratum germinativum because these cells give rise
to new epithelial cells
14. 3. Stratum Granulosum
Cells of stratum granulosum are flat and are found in layers of three
to fivecellsthick
This layer is prominent in keratinized epithelium (and absent in
nonkeratinized epithelium)
Thesecellshavekeratohyalinegranulesin their cytoplasm
Keratohyaline granules help to form the matrix of the keratin fibres
found in thesuperficial layer
15. 4. Stratum Corneum
Cellsof stratum corneum areflat, devoid of nuclei and full of keratin
filament surrounded by amatrix
These cells are continuously being sloughed and are replaced by
epithelial cellsthat migratefrom theunderlying layers
16. Nonkeratinized oral epithelium
Nonkeratinized epithelial cells in the superfecial layers do not have
keratin filamentsin thecytoplasm
Thesurfacecellsalso havenuclei
Thestratum corneum and stratum granulosum layersareabsent
Thisepithelium isassociated with lining of theoral cavity
20. Connective tissue
Connective tissue can be differentiated as Lamina Propria and
Submucosa
Lamina propria
Lamina propria is the connective tissue layer immediately below the
epithelium
It can bedivided into papillary layer and thereticular layer
Papillary layer forms finger like projections of connective tissue that
extend deep in theepithelial layers
21. Papillary layer is prominent in masticatory mucosa and reticular
layer isprominent in lining mucosa
Lamina prorpria consists of blood vessels and cells like fibroblasts,
cellsof blood vesselsand lymphaticsand nerves
Epithelium is avascular, hence its metabolic needs come via the
vesselsof thelaminapropria
22. Submucosa
Submucosa lies below the lamina propria and serves as an
attachment between laminapropriaand boneor skeletal muscle
It isfound in thecheeks, lipsand partsof thepalate
It consists of large blood vessels, nerves and lymphatics and its
functionsarenutrition and defense
23. 2. Functional types of Oral Mucosa
Lining mucosa and Masticatory mucosa
Lining mucosa
Lining mucosa covers all soft tissue of the oral cavity except the
gingiva, hard palateand thedorsal surfaceof thetongue
Lip
Lip iscovered by lining mucosa
Lip with skin on outer surface and
lining mucosa on inner surface
24. Vermilion border
The junction between the skin and mucous membrane is known as
thevermilion border
Here the epithelium is thin therefore, the red blood cells in the
capillariesshow through contributing to thevermilion colour
Vermelion Zone
26. Ventral surface of the tongue
Thelining mucosa here contains both lamina propria and submucosa
The submucosa merges with the muscle bundles of the ventral
surfaceof thetongue
Ventral surface of tongue
29. Cheek
In the cheek the underlying submucosa contains fat cells and small
mixed salivary glands
Cheek
30. Floor of the mouth
The mucous membrane of the floor of the mouth is thin and loosely
attached to theunderlying structures
Floor of the mouth
31. Masticatory mucosa
Masticatory mucosacoversthegingivaand hard palate
In edentulous mouth, masticatory mucosa covers the chewing
surfaceof thedental arches
Gingiva
Gingiva has keratinized or parakeratinzed epithelium with no
submucosal layer
It develops from the union of oral epithelium and reduced enamel
epithelium of thedeveloping tooth
Gingiva can be classified as free gingiva, attached gingiva and
interdental papilla
35. Free gingiva (or marginal gingiva)
It is that part of the oral mucosathat surrounds the necksof theteeth
and formsthefreemargin of thegingival tissue
It is differentiated apically from the attached gingival by the free
gingival groove
Theinner sideof it formsthegingival sulcus
The free gingival mucosa is composed of stratified squamous
epithelium that may be keratinized, parakeratinzed or sometimes
nonkeratinized
39. Attached gingiva
The attached gingiva lies 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 (orange-peel
appearance) which isacharacteristic of thistypeof mucosa
43. Interdental papilla
Interdental papillae are those parts of gingival tissue that appear in-
between teeth apical to thecontact points
Interdental grooves extend vertically between the interdental papilla
corresponding to thedepressionsbetween theroots
Confirming to the shape of the interproximal contact area is a valley
likedepression in theinterdental papillacalled Col.
Thisdepression liesin thefacial and lingual plane
45. Diagram of positional relation of col in health
and disease for canine, premolar and molar
Col accentuated during inflammation (arrows)
46. Junctional epithelium
Junctional epithelium forms the seal of the gingival epithelium and
thetooth
It forms the floor of the gingival sulcus and extends apically to the
enamel of thetooth
Disturbances of epithelial attachment results in deepening of the
sulcuswhich isasign of gingival/periodontal disease
52. Hard palate
The surface of the hard palate that is visible in the mouth is covered
by masticatory mucosa
Thelateral regionsof theposterior part contains palatineglands
Theseglandsarepurely mucousglands
The midline of the hard palate is called median raphe where there is
no submucosa
A seriesof foldsappear in theanterior part of thepalatecalled rugae
54. 3 Mucosa of the Tongue
Specialized mucosa covers the dorsal surface of the body of the
tongue
The connective tissue binds the epithelium to the underlying skeletal
muscle
The epithelium is modified, keratinized, stratified covered with
papillae, which can beseen by naked eye
55. Thedifferent papillaefound on thedorsal surfaceof thetongueare:
1.Filliform papillae
2.Funginform papillae
3.Circumvallate papillae
4.Foliate papillae
Dorsum of Tongue
57. 1. Filliform papillae
Filliform papillae are pointed extensions of the keratinized epithelial
cells
They arethemost numerouspapillaeof thetongue
They arenot associated with tastebuds
Scanning electron micrograph of
Filliform papillae(arrow)
59. 2. Fungiform papillae
Fungiform papillae are fewer than the filliform papillae and are
scattered over thedorsal surfaceof thetongue
They arerounded elevationsabovethesurfaceof thetongue
They havetastebudson their superior surfaces
Thesurfaceof fungiform papillaeisnot keratinized
62. 3. Circumvallate papillae
The circumvallate papillae are located at the junction of the anterior
two thirds(body) and posterior onethirds(base) of thetongue
There are eight to twelve in number and are bigger than fungiform
papillae
Circumvallatepapillaearelined with tastebudsand also openingsof
serousglands
The secretion from the serous glands washes away food for renewal
of taste
64. 4. Foliate papillae
Foliate papillae are located in the furrows along the posterior sides
of thetongue
They may belined with tastebuds
They arenot prominent in human beings
