MICROSCOPIC FEATURES OF

GINGIVAPRESENTED BY DR.SUHANI GOEL MDS-2016

ITS DENTAL COLLEGE GREATER NOIDA

DEPARTMENT OF PERIODONTOLOGY

MODERATOR-DR SURBHI GARG

PERCEPTOR-DR SNEH NIDHI

TABLE OF CONTENTS

PERIODONTIUM

INTRODUCTION OF GINGIVA

MICROSCOPIC FEATURES

GINGIVAL EPITHELIUM

ORAL EPITHELIUM

LAYERS OF ORAL EPITHELIUM

SULCULAR EPITHELIUM

JUNCTIONAL EPITHELIUM

CONNECTIVE TISSUE

GINGIVAL FIBRES

BLOOD SUPPLY OF GINGIVA

LYMPHATIC DRAINAGE OF GINGIVA

GINGIVAThe part of oral mucosa that covers the alveolar processes of jaws

and surrounds the neck of the teeth. CARRANZA

(10TH EDITION)

Is that part of masticatory mucosa covering alveolar processes and cervical portions of teeth.

LINDHE(5TH EDITION)

STRATIFIED SQUAMOUS EPITHELIUM

CENTRAL CORE OF

CONNECTIVE TISSUE

GINGIVA

ORAL (OUTER EPITHELIUM)

SULCULAR EPITHELIUM

JUNCTIONAL EPTHELIUM

GINGIVAL EPITHELIUM

FUNCTIONS OF GINGIVAL EPITHELIUM

PHYSICAL BARRIER TO INFECTION

SIGNALING FURTHER

HOST REACTIONS

INTEGRATING INNATE AND ACQUIRED IMMUNE

RESPONSE

INNATE HOST

RESPONSE

EXTENTCovers crest and outer

surface of marginal gingiva and surface of

attached gingiva.

THICKNESS0.2-0.3mm

KERATINIZATIONkeratinized or

parakeratinized

ORAL (OUTER)EPITHELIUM

11

TWO POPULATION OF CELLS

PROGENITOR MATURING

Divide and provide new cells

Differentiation and maturation to form a protective surface layer

LAYERS OF ORAL EPITHELIUM

STRATUM CORNEUM(KERATINIZED CELL LAYER)

STRATUM GRANULOSUM(GRANULAR LAYER)

STRATUM SPINOSUM(PRICKLE CELL LAYER)

STRATUM BASALE(BASAL LAYER)

STRATUM BASALE(BASAL LAYER)

• cylindrical/cuboidal basal cells

• Contact with basement membrane

• Mitotic cell division• Stratum Germinativum• Progenitor cell compartment • Show ribosomes and rough

endoplasmic reticulum

Protein synthesis activity

STRATUM BASALE

IT TAKES APPROX 1 MONTH FOR THE KERATINOCYTE TO TRANSVERSE THE OUTER EPITHELIAL SURFACE

STRATUM BASALE

K1,K2 AND K10 TO K12- SPECIFIC TO EPIDERMAL TYPE DIFFERENTIATION

K6 AND K16- CHARACTERISTIC OF HIGHLY PROLIFERATIVE EPITHELIA

K5 AND K14- STRATIFICATION SPECIFIC

PARAKERATINIZE AREA EXPRESS- K19

KERATINS

TONOFILAMENTS

DESMOSOMES

HEMIDESMOSOMES

05/02/23

Consists of two adjoining hemisdesmosomes separated by a zone containing electron dense granulated material(GM).

OUTER LEAFLET INNER LEAFLET

ATTACHMENT PLAQUE

GRANULATED MATERIAL

STRATUM SPINOSUM

• CELLS- Irregular polyhedral cells larger than basal cells• Show first sign of maturation SPINY OR

PRICKLELIKE APPEARANCE

Cells frequently shrink away from each other,remaining in contact only at points known as INTERCELLULAR BRIDGES OR DESMOSOMES

(PRICKLE LAYER)

FEATURES OF STRATUM SPINOSUM

WIDE INTERCELLULAR SPACES

PRICKLE CELLS RESEMBLE COCKLEBURR OR STICKER THAT HAS EACH SPINE ENDING AT A DESMOSOME

MOST ACTIVE IN PROTEIN SYNTHESIS SO THEY CONTAIN: NUCLEI SHOW WIDE SPREAD CHROMATIN WELL DEVELOPED GOLGI APPARATUS ROUGH ENDOPLASMIC RETICULUM WITH RIBOSOMES NUMEROUS MITOCHONDRIA

05/02/23

STRATUM GRANULOSUM

CELLS- larger and flatter show increase maturationNUCLEUS signs of degeneration

and pyknosisCYTOPLASM- tonofilaments and

tonofibrils

KERATINOHYALINE GRANULES)Small granules that stain with acid dyes such as hematoxyline.Thus basophilic in nature .ODLAND BODIES are present.

KERATINOHYALINE GRANULES

BASOPHILIC UNDER LIGHT MICROSCOPE

ELECTRON DENSE STRUCTURES

ELECTRON MICROSCOPE

Irregular in shapeProbably synthesized by ribosomesAssociated with tonofibrilsFacilitate the aggregation and formation of crosslinks

between the cytokeratin filaments of the keratinized layerFor this reason protein making the bulk of these granules is called FILAGGRIN

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STRATUM CORNEUM

Outermost layer of keratinized oral mucosa

Cells--. Flat and tightly packed Nuclei- no nuclei Keratohyaline granules

disappeared. Acidophilic –red staining with

hematoxylin and eosin.

Main function PROLIFERATION

DIFFERENTATION

Morphologic changes:1.Progressive flattening of the cell with an increasing prevalence of tonofilaments2.Intercellular junctions coupled to the production of keratohyaline granules3.Disappearance of the nucleus

Dendritic cells Basal & spinous layers Premelanosomes/melanosomes

TYROSINE DIHYDROXYPHENYLALANINE(DOPA)

MELANIN MELANOPHORES/MELANOPHAGES

TYROSINASE

Dendritic cells Modified monocytes Suprabasal layer g-specific granules (Birbeck’s granules) Found: Oral epithelium & sulcular epithelium Absent: Junctional epithelium

Deeper layer Harbor nerve endings Tactile perceptors

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SULCULAR EPITHELIUM

Lines gingival sulcus STRUCTURE-Thin non-keratinized

stratified squamous epithelium EXTENT- Coronal limit of

junctional epithelium to crest of gingival margin

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K4 and K13- ESOPHAGEAL TYPE CYTOKERATINSK19 CYTOKERATINS

SEMIPERMEABLE MEMBRANEINJURIOUS BACTERIAL PRODUCTS

GINGIVA

TISSUE FLUID FROM GINGIVA

SULCUS

05/02/23

POTENTIAL TO KERATINIZE IF

1.REFLECTED AND EXPOSED TO ORAL CAVITY

2.BACTERIAL FLORA OF SULCUS TOTALLY ELIMINATED

05/02/23

COLLARLIKE BAND OF STRATIFIED SQUAMOUS NON KERATINIZING EPITHELIUM

05/02/23

• CORONALLY- 10 -30 cells thick APICALLY- 1-2 cells• LENGTH- 0.25-1.35mm• Exhibit numerous ribosomes• Membrane bound structures- golgi

apparatus,cytoplasmic vacuoles• Lysosome also present• Absence of keratinosomes(odland

bodies)• Numerous migrating PMN’s• Larger intercellular spaces

05/02/23

DEVELOPMENT OF JUNCTIONAL EPITHELIUM

05/02/23

FACING CONNECTIVE TISSUE

TOWARDS TOOTH SURFACE

05/02/23

EPITHELIAL ATTACHMENT APPARATUS

Gottlieb(1921) coined term EPITHELIAL ATTACHMENT EPITHELIAL ATTACHMENT

Attachment apparatus ie internal basal lamina + hemidesmosomes that connects junctional epithelium to tooth surface

05/02/23

Consists of 1.Hemidesmosomes at plasma membrane of cells2.Basal lamina like extracellular matrix- INTERNAL BASAL LAMINA

BY MORPHOLOGICAL CRITERIA

Internal basal lamina between junctional epithelial DAT cells and enamel is quite similar to basement membrane between epithelium and connective tissue.

BY BIOCHEMICAL CRITERIA

Internal basal lamina differs from established basement composition and thus by external basal lamina

EPITHELIAL ATTACHMENT APPARATUS

05/02/23

LAMINA DENSALAMINA LUCIDA

HEMIDESMOSOMES

05/02/23

05/02/23

05/02/23

GINGIVAL CONNECTIVE TISSUE (LAMINA PROPRIA)

PAPILLARY LAYER RETICULAR LAYER

• Subjacent to epithelium• Consists of papillary

projections between epithelial rete pegs

• Contiguous with periosteum of alveolar bone

05/02/23

Papillary layer

Reticular layer

05/02/23

Predominant connective tissue cells(65%)

Spindle or stellate shaped with oval nucleus containing one or more nucleoli

Function- maintains structural integrity of connective tissue by secreting extracellular matrix.

FIBROBLAST

MAST CELLS

Large spherical or elliptical mononuclear cell

Present in relation to blood vessels so they play a role in maintaining normal tissue stability and vascular homeostasis

05/02/23

Well developed nucleus,golgi apparatus

Numerous vesicles Scarse granular endoplamic

reticulum Phagocytic function

Includes NeutrophilsLymphocytesPlasma cells

Includes NeutrophilsLymphocytesPlasma cells

MACROPHAGES

INFLAMMATORY CELLS

05/02/23

COLLAGEN FIBRES

Predominate in gingival connective tissue.

05/02/23

RETICULIN FIBRES

Argyrophilic staining properties Numerous in tissue adjacent to

basement membrane Occur in large no. in loose

connective tissue Present at epithelium-

connective tissue interface

OXYTALAN FIBRES Scarse in gingiva but numerous in PDL

Composed of long thin fibrils with diameter of approx. 150 A

05/02/23

ELASTIC FIBRES

Only present in assosciation with blood vessels of gingiva and PDL.

Gingiva coronal to mucogingival junction (MGJ) does not contain elastic fibres except in association with blood vessels.

05/02/23

GINGIVAL FIBRES

CONNECTIVE TISSUE OF MARGINAL GINGIVA IS DENSELY COLLAGENOUS CONTAINING A PROMINENT SYSTEM OF COLLAGEN FIBRE BUNDLE

CONSIST MAINLY OF TYPE1 COLLAGEN.

FUNCTIONS OF GINGIVAL FUNCTIONS OF GINGIVAL FIBRESFIBRES

05/02/23

EXTENTFacial, lingual & interproximal surfacesOriginate at cementumFanlike conformation Interproximally : Extend towards crest of the interdental gingiva

FUNCTION:Provide gingival support

dentogingival fibres

EXTENT-From periosteum covering height of alveolar crestSplay coronally into substance of the attached gingiva

FUNCTION-Attach gingiva to bone

EXTENTArise in cementum INSERTIONCrest of alveolar processLateral aspect of cortical plate

FUNCTIONAnchor tooth to boneProtect PDL

EXTENT•Marginal & Interdental gingivae•Encircle each tooth•Cuff /Ring like fashion

FUNCTIONMaintain contour & position of free marginal gingiva

EXTENTInterproximallyHorizontal bundlesbetween epithelium at base of crest of gingival sulcus and interdental bone

FUNCTIONsupport interdental gingivaprotect interproximal bonesecure position of adjacent teeth

Most abundant of secondary fibres

EXTENTLateral aspect of alveolar bone

Splay laterally, coronally & apically

FUNCTIONAttach gingiva to boneProvide support & tone within attached gingiv

EXTENTWithin substance of interdental papilla Coronal to transeptal fiber

FUNCTIONProvide support for interdental gingiva

EXTENTZigzag course around dental arch

Seen in and around the the teeth withinattached gingiva.

FUNCTIONMaintain the alignment of teeth in

the arch

EXTENTOriginate from cementum near

the distal line anglesInsert into mesial cementum of

next distal tooth

FUNCTIONMaintain arch integrity

EXTENTCourse in a mesiodistal within attached gingivaDo not insert into any calcified structure

FUNCTION

Provide form, support & contour of attached gingiva

EXTENTMesial surface of one tooth to

distal surface of sametooth in half circle

FUNCTIONMaintenance of arch intergrity

SUPRAPERIOSTEAL ARTERIOLES

Facial and lingual surfaces of alveolar bone Capillaries extend along sulcular epithelium Between rete pegs of outer epitheliumOccasional branches of arterioles pass through Alveolar bone PDL Over the crest of alveolar bone

ARTERIOLES FROM CREST OF INTERDENTAL SEPTA

Extend parallel to crest of alveolar boneAnastomosis:Vessels of PDLCapillaries in gingival crevicular areasVessels that run over alveolar crest

VESSELS OF PERIODONTAL LIGAMENT

Extend into gingivaAnastomosis: With capillaries in sulcular area

LYMPHATIC DRAINAGE

LYMPHATIC DRAINAGE

REFERENCES

1. Carranza’s Clinical Periodontology 10th edition Michael G Newman Henry H Takel Perry R Klokkevold Fermin A Carranza

2. Oral histology Ten Cate’s3. Marja T. Pollanen, Jukka I. Salonen & Veli-Jukka Uitto. Structure and function of

the tooth–epithelial interface in health and disease. Periodontology 2000, Vol. 31, 2003, 12–31

4. Lindhe, Karring, Lang: Clinical Periodontology & Implant Dentistry. Blackwell Munksgaard; 5th Edititon.

5. Thomas M. Hassell. Tissues and cells of the periodontium. Periodontology 2000, Vol. 3, 1993, 9-38.