Oral mucous membrane /certified fixed orthodontic courses by Indian dental academy

•ORAL MUCOUS MEMBRANE
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


 CONTENTS


1. INTRODUCTION



2.DEVELOPMENT



3.FUNCTION





4.TISSUE COMPONENTS OF ORAL
MUCOSA
5.DIVISION OF ORAL MUCOSA



PROSTHODONTIC CONSIDERATIONS



6.BEHAVOIUR OF ORAL MUCOSA UNDER STRESS





7.INFLAMATION AND ORAL MUCOSA .
8.INFLUENCE OF LOCAL AND SYSTEMIC DISEASE
ON
ORAL MUCOSA.



9.SUMMARY & CONCLUSION



10.REFERENCES.


 INTRODUCTION







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.

 DEVELOPMENT









Primitive oral cavity develops from the fusion of the
embryonic stomodeum with foregut after the rupture of
buccopharyngeal membrane.(26 days)
Oral cavity is lined by both ectoderm and endoderm.
Structures developed from brachial arch
Ectoderm ---tongue
Endoderm---Palate ,cheeks ,Gingiva

 FUNCTIONS OF THE ORAL MUCOSA

•
•
•

•

•

1.PROTECTION.
Protects the deeper tissues and organs.
Adapts to withstand mechanical forces.
Barrier in preventing microorganism.
2.SENSATION.
Receptors responsible for the taste , thirst,
temperature.
3.SECRETION.
Major &minor salivary gland secretions –secrete
protective substance.

 COMPONENT TISSUE



A. ORAL EPITHELIUM



B.LAMINA PROPRIA



C.SUBMUCOSA


 DIVISION OF ORAL MUCOSA


 EPITHELIUM






Epithelium of the oral
mucosa is stratified
squamous epithelium.
It may be ;
1.Keratinized
2.Non keratinized
Keratinized layer
ortho keratinized
Para keratinized


 KERATINIZED EPITHELIUM


 NON KERATINIZED EPITHELIUM


 CELLS OF NON KERATINOCYTES









MELANOCYTES; Synthesize
melanin pigment granules & transfer
to surrounding keratinocytes
LANGERHANS CELL ; Antigen
trapping & processing.
MERKEL CELL ; Tactile sensory
cell.
LYMPHOCYTES ; Associated with
inflammatory response in oral
mucosa.

 SMOKERS MELANOSIS








Smoking tobacco imparts smokers melanosis.
Deposition of melanin in basal layer of mucosa.
Affects elderly person –heavy smokers.
Appears as a diffuse brown patch.
Mandibular ant. Gingiva & buccal mucosa commonly
affected.
Labial mucosa ,palate, tongue, floor of the mouth ,
lips .

 JUNCTION OF THE
EPITHELIUM, & LAMINA
PROPRIA.






The region where connective tissue of the lamina
propria meets the overlying epithelium.
Metabolic exchange between epithelium & CT takes
place
Epithelium has no blood vessels.










The interface consists
of CT ridges ,conical
papillae projecting into
the epithelium.
The surface area of the
interface is flat &
provide better
attachment
It helps in dissipating the
force applied on the
epithelium to greater
area of CT.
MASTICATORY
MUCOSA has greater
number of papillae per
unit area .



It is also called as BASAL LAMINA.



Two zones ;

Lamina Lucida






45 nm wide.

Lamina densa.

Towards epithelium .
Quite clear.
Glycoprotein.
Bullous phemphigoid antigen.

50 nm thick .

Towards tissue.
Granular.
Type 4 collagen
Proteoglycon.
.






Basal lamina attached by
hemidesmosomes.
The tonofilaments , desmosomes ,
hemidesmosomes together
represents the mechanical linkage

 FUNCTIONS






Provides mechanical bond .
Semipermeable, acts as a barrier.
Respond to tissue injury.
MUCOSAL BLISTER; Separation of the

epithelium from the connective tissue at
Lamina lucida


 LAMINA PROPRIA
The connective tissue supporting the oral
epithelium
is termed lamina propria.

Two layers ;









1.PAPILLARY LAYER.
Close to epithelial ridges.
Arranged loosely.
2.RETICULAR LAYER
parallel to epithelium
fibers are very thick.
form network
It consists of cells , blood vessels ,
neural elements & fibers embedded in
amorphous ground substance


 CELLS FOUND IN LAMINA
PROPRIA










Fibroblast - secretion of fibers &ground substance
Histiocytes - precursor of macrophage
Macrophages - phagocytosis
Mast cell - inflammatory mediator (kinins),
vasoactive agent (histamine)
Polymorphonuclear leucocytes - phagocytosis
Lymphocytes - cell mediated immune response
Plasma cells - synthesis immunoglobulin
Endothelial cells - lining of blood & lymphatic
channels


 SUBMUCOSA
.






Consists of connective
tissue of various thickness .
It attaches the mucous
membrane to the
underlying structures.
It may be a loose or a firm
attachment - to glands,
blood vessels , nerves, and
adipose tissues

 DIVISION OF THE ORAL MUCOSA







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




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



KERATINZED AREAS
MASTICATORY MUCOSA.
GINGIVA
HARD PALATE
VERMILION BORDER OF LIP
NON KERATINIZED AREAS
LINING OR REFLECTING MUCOSA
LIP
CHEEK
VESTIBULAR FORNIX
ALVEOLAR MUCOSA
FLOOR OF THE MOUTH
SOFT PALATE
SPECIALIZED MUCOSA
DORSUM OF THE TONGUE

 REGIONAL VARIATIONS;
MAXILLARY EDENTULOUS
FOUNDATION










CREST OF THE RESIDUAL
RIDGE
Firmly attached to the bone.
Keratinized epithelium
Dense collagen fibers
Sub mucosa – fat or glandular cells
Although the sub mucosa is thin it
is thick to provide adequate
resiliency for primary support of
denture .


 SLOPES OF RESIDUAL RIDGE






Non keratinized or Para keratinized.
Tissues are loosely attached to periosteum.
This marks the end of residual attached mucous
membrane.
These tissues will not withstand the masticatory
and other stress.
Less stresses should be placed on the movable
tissue during impression making.


 ALVEOLAR MUCOSA












EPITHELIUM ; thin
nonkeratinized
LAMINA PROPRIA;
Short papillae
CT contains many elastic fibers .
Capillary loops close to the surface.
Vessels –run superficial to the
periosteum.
SUB MUCOSA
Loose CT
Thick elastic fibers connects periosteum
–alveolar process


 REGIONS OF HARD PALATE


 HARD PALATE

.EPITHELIUM; thick
orthokeratinized
 LAMINA PROPRIA ; long papillae, thick
collagenous tissue especially under rugae
Moderate vascular supply with short capillary
loops.
 SUBMUCOSA;
Dense collagenous CT attaching mucosa to
periosteum .
Fat & minor salivary gland – CT –overlying
neurovascular bundle.



 CLINICAL SIGNIFICANCE






Tissues should be recorded in resting
position .
If the tissues displace during impression
procedures, they tend to return to normal
Such dentures cause soreness of mouth.


 MID PALATINE SUTURE







Extends from the incisive papilla to posterior
region of hard palate .
Sub mucosa is very thin .
Mucosal layer is practically in contact with
underlying bone .
Tissue covering the suture is non resilient


 CLINICAL SIGNIFICANCE






Little or no pressure should be applied to this region
.
This area is highly sensitive .
Excessive pressure in this area causes pain .
Relief should be given in this area







 PALATINE RUGAE

Irregularly shaped rolls of soft tissue in the anterior part of
hard palate.
It is a secondary stress bearing area
It resists forward movement of denture.


 SOFT PALATE






EPITHELIUM;
thin
Non keratinized, taste buds
LAMINA PROPRIA;
thick
numerous papillae, elastic fibers
Highly vascular- developed capillary
network.
SUB MUCOSA; diffuse tissue containing
minor salivary glands


 BLOOD & NERVE SUPPLY OF PALATE


 BLOOD & NERVE SUPPLY OF PALATE




Tonsillar branch – glossopharengeal
nerve
MOTOR SUPPLY ;Pharyngeal plexus.

 STOMATITIS NICOTINA PALATI









Response of oral mucosa to
prolong smoking.
Middle , elderly men.
Initially- diffuse erythematous.
Palate becomes grayish white
,sec to hyperkeratosis.
Multiple discrete keratotic
papules with depressed red
center.
opening of the glands dilate &
inflame.
Papules enlarge if irritation
persist.

 BUCCAL- LABIAL MUCOSA
EPITHELIUM; thick
Non keratinized.
 LAMINA PROPRIA;
 Long slender papillae, dense fibrous
CT containing collagen & elastic
fibers .
 Rich vascular supply. Anastomosing
capillary loops into papillae.
 SUBMUCOSA; firmly attached to
the
under lying muscles by collagen &
elastin
Fat, minor salivary gland .






FORDYCE’S SPOTS

Fordyce’s spots are ectopic
sebaceous glands present in the
buccal and labial mucosa.


 LINEA ALBA





A raised white wavy line
of variable length and
prominence located at the
level of occlusion.
Thin keratin layer.


VESTIBULAR SPACES








It is bound facially by mucosa of lips , cheek &
orally by mucosa of residual ridge .
Vestibule is divided medially by labial frenum &
laterally by buccal frenum.
Epithelium is thin & nonkeratinized.
Submucosa is thick ,
Large amount of loose areolar tissue.


 FRENUM








It is fold of mucous
membrane
Labial frenum is fan
shaped
Buccal frenum is
associated with muscles
Relief should be provided
in denture

 VIBRATING LINE






It is an imaginary line
drawn across the soft
palate.
Sub mucosa contains
glandular tissue .
Lamina propria has
elastic fibers.

 MUCOUS MEMBRANE OF HAMULAR
NOTCH




Space between the posterior part of the
maxillary tuberosity & pterygoid hamuls
It is thick and is made of loose areolar
tissue.










MANDIBULAR EDENTULOUS
FOUNDATION
SUPPORTING STRUCTURES

CREST OF THE RESIDUAL
RIDGE
It is similar to maxillary ridge.
Keratinized epithelium .
Sub mucosa is loosely
attached.
Nutrient canal openings.

When the soft tissue is
movable in the crest of the
ridge ,impression should be
recorded in its resting position.

 BUCCAL SHELF







Partially keratinized.
Loosely attached.
Thick submucosal layer.
Bone – compact bone
That why it is primary
stress bearing area.


 VESTIBULAR SPACES






Similar to the maxilla.
Epithelium is thin .
Non-keratinized .
Submucosa- loose areolar tissue ,elastin fibers.


 MOLAR REGION





Here the sub mucosa is attached to the
mylohyoid muscle .
Length and form of the lingual flange of the
tray should reflect the physiologic activity
of these structures .

 RETROMOLAR PAD







Epithelium is thin .
Non-keratinized .
Submucosa – glands , loose
areolar tissue , blood vessels
…..
CLINICAL SIGNIFICANCE
Because of these structures
impression should be
recorded in resting position .


FLOOR OF THE ORAL CAVITY
EPITHELIUM; very thin
Non keratinized .
 LAMINA PROPRIA ;Short papillae.
Elastic fibers.
Extensive vascular fibers.
Short anastomosing capillary loops
 SUBMUCOSA ;loose fibrous CT
Fat, minor salivary glands .
 BLOOD SUPPLY;
Sublingual artery branch of lingual
artery.





FLOOR OF THE MOUTH








Extension of the dentures
posterior lingual flanges
usually will allow for a stable
denture.
This objective will not be
fulfilled in this case,
Unfavorable high
attachment & mobile floor
of the mouth.

 LIPS
VERMILION ZONE


EPITHELIUM; thin ,
orthokeratinized.



LAMINA PROPRIA; narrow
papillae.





Capillary loops close to
surface layer
SUBMUCOSA; mucosa
firmly attached to the
underlying muscles .


 INTERMIDIATE ZONE









EPITHELIUM; thin
Para keratinized
LAMINA PROPRIA; long
,irregular papillae, elastic
fibers ,collagen fibers
SUBMUCOSA; mucosa is
firmly attached to muscle
,sebaceous gland
,minor salivary gland ,fat.

 BLOOD & NERVE SUPPLY








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BLOOD;
UPPER LIP; SUPERIOR LABIAL ARTERY
LOWER LIP; INFERIOR LABIAL ARTERY
MENTAL ARTEY
branch of inferior alveolar artery.
NERVE
UPPER LIP ; INFRAORBITAL branch of max nerve .
LOWER LIP; MENTAL branch of inferior alveolar .
BUCCAL branch of mandibular nerve .


 GINGIVA.











EPITHELIUM; Ortho-keratinized
Para-keratinized ,stippling .
LAMINA PROPRIA ;long narrow
papillae
Dense collagenous CT .
Not highly vascular, but long capillary
loops with anastomoses are present .
SUB MUCOSA ; no distinct layer .
Mucosa is firmly attached by collagen
fibers to cememtum & periosteum of
alveolar process.

 GINGIVA
A. ALVEOLAR MUCOSA
D. ATTACHED GINGIVA

B. GINGIVA C. MUCOGINGIVAL JUNCTION
E. FREE GINGIVA

F. INTERDENTAL GINGIVA


 TYPES OF EPITHELIUM IN GINGIVA


3 TYPES;



1.Outer epithelium



2. Sulcular epithelium



3.Junctional epithelium


 INTERDENTAL GINGIVA











COL

Non keratinized
Depression between
buccal & lingual papilla
Connects both the papilla
Found below the contact
point
Anteriorly – pyramidal
Posteriorly – tent shape.

•BLOOD SUPPLY















UPPER GINGIVA

ANTERIOR;ANTERIOR SUPERIOR ALVEOLAR ARTEY
PALATAL; GREATER PALATINE ARTERY
BUCCAL ;BUCCAL ARTERY
POSTERIOR; POSTERIOR SUPERIOR ALVEOLAR ARTERY

LOWER GINGIVA
ANTERIOR
ANTERIOR

BUCCAL; MENTAL ARTERY
LINGUAL; INCISIVE ARTERY
SUBLINGUAL ARTERY
POSTERIOR BUCCAL; INFERIOR ALVEOLAR ARTERY
BUCCAL ARETRY
POSTERIOR LINGUAL; INFERIOR ALVEOLAR ARTERY
SUBLINGUAL ARTERY

•NERVE SUPPLY









UPPER GINGIVA;

ANTERIOR, POSTERIOR, MIDDLE SUPERIOR
ALVEOLAR BRANCH OF MAXILLARY NERVE

LOWER GINGIVA;

INFERIOR BRANCH OF MANDIBULAR NERVE
BUCCAL BRANCH OF MANDIBULAR NERVE
SUBLINGUAL BRANCH OF LINGUAL NERVE

 TONGUE
DORSAL SURFACE OF TONGUE











EPITHELIUM; thick
Keratinized &nonkeratinized
Lingual papillae's are present
Taste buds
LAMINA PROPRIA; long papillae
Minor salivary glands posteriorly.
Rich innervations near taste buds .
Capillary plexus in papillary layer large vessels lying
deeper
SUB MUCOSA ; No distinct layer .







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




FILLIFORM PAPILLAE

keratinized
Anterior tongue
Smallest & numerous
Hair like extensions
FOLIATE PAPILLAE

Non keratinized
Lateral margins
Leaf like projections
Few taste buds



FUNGIFORM PAPILLAE

Non keratinization
Anterolateral
Taste buds
Round & reddish.


CIRCUMVALLATE PAPILLAE

Keratinized –superiorly
Nonkeratinized- laterally
Anterior to sulcus terminalis

 TASTE BUDS



Chemoreceptor organs
Barrel shaped
seen in –fungiform papillae
circumvallate papillae
soft palate ….


VENTRAL SURFACE OF THE
TONGUE


•







EPITHELIUM; Thin, non
keratinized .
LAMINA PROPRIA ;Thin ,
Numerous short papillae .
Few elastic fibers .
Minor salivary glands. capillary
network in sub papillary layer
Reticular layer relatively avascular
SUBMUCOSA; Thin & irregular
Fat & small vessels
Bound to the CT surrounding the
tongue musculature.


 LINGUAL VERUCOSITES
( PHLEBECTASIA )










Common in elder individuals.
Purplish blue nodular area.
Due to dilation & increased tortusity of
lingual veins.
Increase venous pressure
decrease in elasticity of venous wall.
Lack of support by surrounding tissues.

COMPLICATIONS;

Ulceration, thrombosis, hemorrhage.


 BLOOD & NERVE SUPPLY OF TONGUE
BLOOD SUPPLY;









Ant 23rd -- deep lingual artery
Post 13rd --dorsal lingual artery
NERVE SUPPLY;

Glossopharengeal nerve
Lingual nerve
Chorda tympani.
Vagus nerve


EFFECT OF AGING ON THE ORAL MUCOSA









HISTOLOGY

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.



These changes in the histology of oral mucosa are more
marked in women especially post menopausal.



Vascular changes in the oral mucosa include the
development of vascular nodules and nevi.




Wound healing and regeneration of tissue may be delayed
with age. Oral mucosal immunity is also believed to undergo
some age related changes. The number of langerhan’s cells
decreases with age which contributes to a decline in cell
medicated immunity.



This decrease in rate of wound healing is more pronounced
in connective tissue than epithelium.


 AGING IN GINGIVA






With the aging there is decreased
keratinization and stippling
Though gingival recession increases with age
it is not necessary a physiologic process.
There is decreased width of attached
gingival with constant relocation of the
mucogingival junction throughout the adult
life.



There is stiffening of the walls of the
blood vessels and decrease in their
diameter due to arthrosclerosis.



Decreased connective tissue cellularity
and oxygen consumption.


 BEHAVIOUR OF ORAL MUCOSA
UNDER STRESS








Oral mucosa under compression behaves in a
viscoelastic fashion.
Loads imposed on masticatory mucosa – mastication &
prosthesis consists of shear & compressive force, they
produce regions of tensile stress in mucosa
Loaded epithelium demonstrates decrease in the depth
of epithelial ridges & connective tissue papillae
Care to be taken during impression procedures by
applying minimal pressures.



Function & Parafunction



PRESSURE

FORCE

TIME





controlled by
Tissue damage caused by
1 correct clinical
occluding local circulation
technique
2 permanent
soft liner


controlled by
nocturnal tissue
rest

 SOFT TISSUE CHANGES IN ORAL MUCOSA














SOFT TISSUE HYPERPLASIA
FIBROUS HYPERPLASIA
EPULIS FISSURATA
PAPILLARY HYPERPLASIA

INFLAMMATORY PROCESS UNDER DENTURE BASES
DENTURE STOMATITIS
STOMATITIS VENENATA
CANDIDIASIS
MECHANICAL IRRITATION
DECUBITUS ULCER
ULCERATIVE LESIONS
ANGULAR CHELITIS


 SOFT TISSUE HYPERPLSIA










Rolls of hyperplastic tissues under denture
base
Due to bone resorbtion, with lesion filling the
space under denture base.
Develops slowly, painless.
Rx

Surgical removal.
New dentures.


 PAPILLARY HYPERPLASIA







Granular type of inflammation seen in palatal region.
numerous papillary projections give a warty appearance.
They show precancerous tendencies
Rx Surgery
Discontinue denture wearing
New dentures

 DENTURE STOMATITIS










Chronic inflammation of the denture bearing
area.
CAUSES;
Para functional habit.
ill fitting denture .
Nocturnal denture wearing.
Hypersensitivity.
Poor oral hygiene
Infections –Candida albicans


 DENTURE STOMATITIS











SYMPTOMS;
Redness of the tissue.
Pain.
Burning sensation
Rx;
Discontinue denture wearing .
good oral hygiene procedures
Anti fugal Rx ( if candidal inf)
New dentures.


 CONTACT STOMATITIS







Certain individuals react to materials & drugs
differently than others do.
In oral cavity it is termed as contact stomatitis.
Marked redness in limited area contact with
acrylic partial denture.
Such contact sensitivity is
rare.


 CANDIDIASIS












Usually seen in,
Unclean mouth.
Debilitated patients
Systemic disease such as diabetes.
Unhygienic conditions will facilitate the
candidal growth.
SYMPTOMS;
Redness with pain.
Swelling of the denture supporting tissue.
Rx Discard the existing denture.
Anti fungal therapy.
New dentures.

 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.



Rx;



Anti fungal therapy.


LOCAL DISEASES AFFECTING ORAL
CAVITY










WHITE LESIONS;
Leukoplakia.
Lichenplanus.
Hyperkeratosis.
MALIGNANT LESIONS.
Carcinoma.
METABOLIC DISEASES.
Diabetes mellitus .
Nutritional disorders.

 LEUCOPLAKIA


 LICHEN PLANUS


 ERYTHROPLAKIA


 CARCINOMA


 NUTRITIONAL DEFICIENCY


 SUMMARY







The oral mucosa consists of stratified
squamous epithelium followed by Lamina
propria & Submucosa.
The structure varies according to function
in different regions they can be classified
as – Masticatory mucosa
Lining mucosa
Specialized mucosa

 CONCLUSION




The dentures must function in harmony with the
remaining tissues that both support and
surround them .
For this harmony of living tissues & non living
materials (dentures) to coexist for reasonable
period of time, the dentist must fully understand
both the macroscopic & microscopic anatomy of
supporting & limiting structures of dentures.

 REFERENCES












1.A.R.Tencate -Oral Histology
,Development ,Structure and Function -- 6th
Edition
2.Anne M R, Ming C Lee Grants atlas of
anatomy 10th Edition.
3.Bouchers –Prosthodontic treatment for
edentulous patients 10th & 11th Edition
4.B.K.B .Bercovitz , Color atlas & text of oral
anatomy .
5.Bernard .L. The anatomical basis of dentistry.
2nd Edition.
6.Colby, Kerr Color atlas of oral pathology. 4th
Edition








7.Hubert E Schroeder -Oral Structural
Biology --3rd Edition
8.John J Sharry -Complete denture
prosthodontics 1962
9.Keith L Moore -Clinically Oriented
Anatomy --3rd Edition
10.Nagle & Sears -Dental Prosthetics ,
Complete denture.
11.Orbans -Oral Histology And
Embryology 11th Edition
12.Zarb-Bolendar Prosthodontic
treatment for edentulous patients 12th
Edition.

Oral mucous membrane /certified fixed orthodontic courses by Indian dental academy

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