Histology of oral mucous membrane including gingiva/certified fixed orthodontic courses by Indian dental academy

Histology of oral mucous
membrane including gingiva
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

Oral mucous membrane
The oral mucosa is the
epithelial lining of the
oral cavity
Oral cavity extends from
skin-vermilion junction
of lips to junction of
hard and soft palate
above and to line of
circumvallate papillae
below

Oral Structures
Buccal cavity
Lips
Cheeks
Hard palate
Soft palate
Tongue
 Lingual papillae
 Taste buds
Gingiva

 Vestibule - trough between the gingiva, lips,
and cheeks.
 Frenum - a narrow band of tissue that
connects two structures
 Labial - located at midline between labial and
alveolar mucosa.
 Buccal - located at bicuspid/molar region
between cheeks and alveolar mucosa.
 Lingual - located at midline between the
ventral surface of the tongue and the floor of
the mouth.

Organization
Has 2 parts –.
1. Outer vestibule – bound by lips and
cheek.
2. Oral cavity proper – separated from
vestibule by the alveolus.
Superior border – hard and soft palate.
Inferior border - tongue and floor of
mouth.
Posterior border – bound by faucial
pillar and tonsils.

Vestibule
Buccal
Frenum
Labial
Frenum

Functions
Protection – impermeable barrier
Sensation - receptors
Secretion - saliva

Classification
Lining mucosa
Masticatory mucosa
Specialized mucosa

Lining mucosa
Soft, moist surface with ability to be compressed
and stretched
Ares of tissue coverage –
Buccal mucosa
Labial mucosa
Alveolar mucosa
Mucosa of the floor of the mouth, ventral surface
of tongue and the soft palate(posterior 1/3)

associated with nonkeratinized stratified
squamous epithelium
smooth interface between epithelium and
lamina propria
elastic fibers in lamina propria
may contain Fordyce granules

Masticatory mucosa
rubbery surface texture and resiliency ,designed
to withstand the vigorous activity of chewing
and swallowing
includes:
attached gingiva
hard palate
dorsal surface of tongue
associated with keratinized stratified squamous
epithelium
highly interdigitated interface

 Covers the hard palate (anterior 2/3 of the
palate).
 Dorsum (top) of the tongue.
 Gingiva.

Specialized mucosa
found on the dorsal surface of
the tongue
associated with lingual papillae

Clinical features
Mucosa continuous with skin
Deeply red colored/pink
Vermillion border in lips
Color gives indication of health of mucosa
Surface is moist with no appendages
Contains salivary glands and some sebaceous glands
on buccal mucosa
Papillae on tongue
Linea alba may be present on cheek,presence of
Fordyce's granules/spots.
Injection into masticatory mucosa is painful

Structure of the oral mucous
membrane
Epithelium
Lamina propria
Submucosa

Epithelium
Stratified squamous epithelium
Epithelial cells
1. Keratinzed – ortho/para-keratinized
2. Nonkeratinized
Cells tightly adherent

Keratinized Epithelium
Stratum basale - area of mitosis
Stratum spinosum
(prickle cell layer) - bulk of. epith.; cells
can’t undergo mitosis
Stratum spinosum - contain prominent
keratohyaline granules
Stratum corneum
(keratin layer )- enucleated cells , filled
with keratin; variable thickness

 Keratinised
epithelium - the
keratinocytes
maintain their nuclei
 Prickle cell layer
 Basal layer
 Rete pegs
 Lamina propria
(underlying
connective tissue)

Para keratinized epithelium
Immature form of ortho-keratinized epithelium
The cornified layers retains shrunken
nuclei/pyknotic nuclei
Associated with masticatory mucosa of the
attached gingiva and the specialized mucosa of
the lingual papillae on the dorsal surface of the
tongue
Usually has same 4 layers but granular layer
may be indistinct or absent

Non keratinized epithelium
Stratum basale
Stratum
intermedium
Stratum
superficiale

CELLS OF EPITHELIUM (non
keratinocytes)
Langerhans cell
Melanocyte - synthesis of melanin
Merkel cell -sensory receptor associated
with nerve endings
Lymphocytes.

BASAL MEMBRANE
LAMIMA LUCIDA
LAMINA DENSA

Lamina propria
All three classifications have lamina propria
deep to basement membrane
mostly collagen fibers but some elastic
has 2 layers with capillaries in between
1. Papillary - more superficial, has loose CT,
blood vessels, nerves
2. reticular - dense, deeper, dense CT with large
amount of fibers ,collagen and elastin
capillary layer - plexus of vessels that provides
nutrition for all the mucosa and sends capillaries
into the CT papillae

CELLS OF LAMINA
PROPRIA
Most common cell in LP is the fibroblast
Other cells:
Polymorphonuclear Leukocytes
Histiocyte
Monocyte
Plasma Cell
Endothelial Cells
Mast Cells
Macrophages
Lymphocytes

Submucosa
Connective tissue of varying thickness and density
makes the bulk of the mucous membrane
Attaches mucous membrane to underlying
structures.
Glands
Blood vessels
Nerves

Structural variations of the oral
mucosa
KERATINIZED AREAS
Masticatory mucosa
Vermillion border of lip
NON KERATINIZED AREAS
Lining mucosa
Specialized mucosa

Keratinized areasKeratinized areas
Masticatory Mucosa(Gingiva &Hard palate)
HARD PALATE
Tightly fixed to
underlying bone
,immovable and pink
Epithelium - thick,
orthokeratinized
Lamina propria -
medial portion, rugae
and raphe serve as a
mucoperiosteum to
bone

Submucosa - present
only in lateral
portions, with
anterior part having
adipose and posterior
part having minor
salivary glands
Zones –
1. Gingival
2. mid palatal
3. Fatty
4. glandular

Incisive Papilla
Dense connective
tissue
Contains oral parts of
vestigial nasopalatine
ducts

Rugae
Irregular and
asymmetric
Ridges of mucous
membrane laterally
from incisive papilla
to anterior part of
raphe
Dense connective
tissue core

Gingiva
Masticatory mucosa that covers the alveolar
processes bound to periosteum of
maxilla/mandible
Pink in Colour
Pigmentation –base of interdental papilla
Epithelium - thick keratinized (mainly
parakeratinized, some orthokeratinized
Lamina propria – dense ,tall, narrow CT papilla-
and distinct elastic layer
Submucosa - not present

Free gingiva
Attached
gingiva
Interdental
papilla

Free gingivaFree gingiva
Border of the gingivaBorder of the gingiva
surrounding the teethsurrounding the teeth
in collar like fashion.in collar like fashion.
Tissue from the topTissue from the top
gingival margin to thegingival margin to the
base of the gingivalbase of the gingival
sulcus.sulcus.
Usually about 1mmUsually about 1mm
wide, and it forms awide, and it forms a
soft tissue wall of thesoft tissue wall of the
gingival sulcusgingival sulcus

GINGIVALGINGIVAL
MARGINMARGIN
UNATTACHEDUNATTACHED
GINGIVAGINGIVA
GINGIVALGINGIVAL
SULCUSSULCUS

Epithelial attachment
 Tissue that
attaches to
the tooth.
 Forms the
base of the
sulcus
EpithelialEpithelial
attachmenattachmen

Attached gingiva
 Firmly bound and resilient.Firmly bound and resilient.
 Stippled, dense tissue that is self-protecting inStippled, dense tissue that is self-protecting in
form.form.
 Extends from the base of the sulcus to theExtends from the base of the sulcus to the
mucogingival junction.mucogingival junction.

GINGIVALGINGIVAL
MARGINMARGIN
UNATTACHEDUNATTACHED
GINGIVAGINGIVA
GINGIVALGINGIVAL
SULCUSSULCUS EPITHELIALEPITHELIAL
ATTACHMENATTACHMEN
ATTACHEDATTACHED
GINGIVAGINGIVA
ALVEOLARALVEOLAR
MUCOSAMUCOSA
MUCOGINGIVALMUCOGINGIVAL
JUNCTIONJUNCTION

Interdental gingiva.
Stippled
extension of
the free
gingiva that fills
the space
between two
teeth.
Also known as
the interdental
papillae.

Gingival fibres of periodontal
ligament
Attach gingiva to the tooth and enter the
lamina propria
Dentogingival
Alveololingual
Circular
Dentoperiosteal

Vermillion border of lip
Red zone at junction of
skin and mucous
membrane of lip
vessels close to surface
transition between
nonkeratinized and
keratinized epithelium
Lamina propria: papillar
organization
Submucosa may have
sebaceous glands www.indiandentalacademy.com

Non keratinized mucosa
lining mucosa
Alveolar mucosa
Labial mucosa
Buccal mucosa
Soft palate
Ventral surface of tongue
Floor of the mouth

Alveolar mucosa
1. Epithelium - thin,
nonkeratinized
2. Lamina propria - CT papillae
sometimes absent, many
elastic fibers, extensive
vascular supply
3. Submucosa - present with
minor salivary glands and
many elastic fibers; loose
attachment to muscle or
alveolar process

Loosely attached to
periosteum
Continuous with
gingiva

Labial and buccal mucosa
Epithelium - thick
Lamina propria -
irregular and blunt CT
papilla; some elastic
fibers, extensive
vascular supply
Submucosa - present
with adipose tissue
and minor salivary
glands; firm
attachment to muscle

Soft palate
Epithelium - thin
nonkeratinized
Lamina propria - thick with
numerous CT papillae and
distinct elastic layer
Submucosa - very thin with
adipose tissue and minor
salivary glands; a firm
attachment to underlying
muscle
Highly vascular and red

Ventral surface of tongue and
floor of mouth
Epithelium - very thin,
nonkeratinized
Lamina propria - extensive
vascular supply; CT papillae,
some elastic fibers, minor
salivary glands
Submucosa - present;
floor - adipose with
submandibular and sublingual
glands, loosely attached to
bone/mucous memb..
ventral tongue - very thin,
firmly attached to mmwww.indiandentalacademy.com

Specialize mucosa
dorsal lingual mucosa
Dorsal surface has both a
masticatory and a
specialized type of mucosa
present
Masticatory is
orthokeratinized stratified
squamous epithelium;
generally covers surface
Specialized found on lingual
papillae has both ortho- and
parakeratinized epithelium

Stratified squamous
nonkeratinized
epithelium covering
striated muscle and
glands
Upper surface is rough
with 4 types of papillae
Filiform, Fungiform,
Foliate, Circumvallate
Posterior half has
lymphoid nodules and
lingual tonsils

Filiform Papillae
Clinically - most
common; fine-pointed
cones
Microscopically -
pointed structure with a
thick layer of
keratinized epithe-lium
overlying a core of
lamina propria; no taste
buds
Function - mechanical

Fungi form papillae
Clinically - fewer;
mushroom-shaped small
red dots
Microscopically -
mushroom-shaped
structure with a thin layer
of keratinized epithelium
overlying a core of lamina
propria, with taste buds in
the most superficial
portion
Function - taste www.indiandentalacademy.com

Vallate papillae
Clinically - 7 to 15 large,
raised mush-room-shaped
structures anterior to the
sulcus terminalis
Microscopically -
mushroom-shaped, sunken
into tongue surface, taste
buds in base, surrounded by
a trough which has von
Ebner’s glands in
submucosa
Function - taste

Foliate papillae
Clinically - 4 to 11
vertical ridges on the
lateral surface of the
posterior tongue
Microscopically - leaf-
shaped structure of
keratinized epithelium
overlying a core of
lamina propria, with
superficial taste buds
Function - taste

Taste buds
Goblet-shaped clusters of cells oriented at right
angles to the epithelium
Extend from the basal lamina to the epithelial
surface
Modified epith. Cells that act as taste receptors
Each has a small pore that opens into the oral
cavity, through which tastable substances may
contact these cells
Have been found not to divide but each is replaced
by differentiation of a peripheral or basal cell in the
bud or surrounding epithelium recent finding:
negligible loss of taste buds in older, healthy
individuals www.indiandentalacademy.com

Junctions of oral mucosa
Muco cutaneous on
lip
Mucogingival
between alveolar
mucosa and gingiva

Renewal rate, repair, aging
Renewal rate, repair, aging Oral mucosa
tissue renewal rate is higher than for skin
Regional differences:
– buccal and labial mucosa - 10 - 14 days
– attached gingiva - 10 days
– taste buds - 10 days
– junctional epithelium - 4 - 6 days

Aging
Clinical observations:
– decreased stippling
– increased Fordyce spots
– lingual varicosities
– decreased lingual papillae, esp. folliate
– decreased production of saliva
Histological observations:
– decreased thickness & rete pegs in epith.
decreased epithelial mitotic activity
– decreased epithelial surface area

decreased keratinization of masticatory
mucosa, esp. attached gingiva
– less defined division between papillary
and dense layers
– thicker collagen fibers, changed elastic
fib.
– decreased quantity and size of
fibroblasts
– decreased ability to repair

Clinical considerations
The denture bases rest on the mucous
membrane which serve as a cushion between
the base and the bone
The thickness and consistency of the
submucosa are responsible for the soft tissue
support of the dentures.
Colour of the mucosa is indicative of the health
of the tissue
 The presence of fatty and glandular tissue in the
submucosa of the hard palate provides the
cushioned type of support and provides the
primary support.

 When the sub mucosal layer is thin , will be non
resilient and small movements of the denture break
the retentive seal.
When the submucosal layer is loosely attached to
the periosteum or inflamed,the tissue will be
displaceable and cause loss of stability.
The submucosa over the crest of the upper ridge is
thick with good resiliency and provides primary
support
Less stress is placed on the movable tissue of the
ridge slopes as the mucosa is loosely attached
,especially during the impression making.
The mucosa of the hard palate should be recorded
in resting(undisplaced) position.www.indiandentalacademy.com

The mucosa of mid palatal region should be
relieved.
In resorbed ridges the anterior mucosa will be
flabby due to the rugae and requires relief as there
is no bone support
The looseness of the labial and buccal mucosa
make it easy to overextend or under extend
impressions and for recording the borders
The mucosa of the region of vibrating line of the soft
palate does not rest on bone ,hence can be
repositioned in a controlled manner to improve
posterior palatal seal.
Additional pressure can be placed on the
submucosa of hamular notch to complete the
pterygomaxillary sealwww.indiandentalacademy.com

Retromolar papilla marks the distal end of the
gingival area
In elder patients the tissue takes many hours to
recover from effect of moderate mechanical force
hence dentures should be removed before the
procedures.
The thicker the tissue ,more is the deformity
Impression materials that flow flow easily after
seating should be used
Relief holes should be provided especially in
maxillary arch.
Excessively thick mucosa may need to be surgically
excised.
Abnormally thick mucosa due to excessive load to
and edentulous ridge In lateral or antero posterior
direction www.indiandentalacademy.com

Various forms of hyperplasia due to
resorption and excess loads
1. Papillary hyperplasia -in centre of
palate,
2. Fibrous hyperplasia – periphery of
dentures due to denture movement
and pressure
3. Irrtitation fibroma
4. Epulis fissuratum

Mucosal lesions
 Fibrous hyperplasia
secondary to ill fitting
dentures
Irritation
fibroma-Fibrous
hyperplasia
secondary to ill
fitting dentures

 Epulis fissuratum
 Denture induced
papillary hyper plasia

Acute atropic candidiasis
Chronic atropic candidiasis

Lesions affecting mucosa of
tongue
Median rhomboid glossitis
Hairy tongue
Benign migratory glossitis
Fissured tongue

Lesions associated with the
gingiva
Gingival hyperplasia
gingivitis

Summary
The oral mucous membrane is an important
determinant in the construction of removable
prosthesis,considering its extent in the oral cavity as
it is in intimate contact with the prostheses .The
histology gives an understanding of requirements
and available factors for the retention and support
of the denture .
An observation of the mucosa gives an initial idea
about the health of the patient and the probable
prognosis.
The knowledge of structure of gingiva and its
related problems aids in better treatment planning
for the removable partial and fixed prostheses

References
Orban’s Oral Histology,And Embryology,11th
Edition,Mosby Publishers,1991
Tencate , Oral Histology, 3rd
Edition, Jaypee
Brothers. 1989
Avery ,Essentials Of Oral Histology
Berkowitt ,Colour Atlas Of Oral Histology
Bouchers,Prosthodontic Treatment For
Edentulous Patients,9th
Edition ,Cbs
Publishers,1990
Heartwells,Syllabus Of Complete Dentures,4th
Edition,Varghese Publishing,1992
A.Roy Maggregor,Clinical Dental Prosthetics,3rd
Edition,Varghese Publishing,1994www.indiandentalacademy.com

Histology of oral mucous membrane including gingiva/certified fixed orthodontic courses by Indian dental academy

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Semelhante a Histology of oral mucous membrane including gingiva/certified fixed orthodontic courses by Indian dental academy

Semelhante a Histology of oral mucous membrane including gingiva/certified fixed orthodontic courses by Indian dental academy (20)

Mais de Indian dental academy

Mais de Indian dental academy (20)

Último

Último (20)

Histology of oral mucous membrane including gingiva/certified fixed orthodontic courses by Indian dental academy