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GINGIVA MICROSCOPIC FEATURES

Dr. Mayur Kaushik

1 Dr. Mayur Kaushik, Subharti Dental College, SVSU

GINGIVA

EPITHELIUM

- Stratified Squamous Epithelium

CONNECTIVE TISSUE

- Papillary & Reticular Layers

2 Dr. Mayur Kaushik, Subharti Dental College, SVSU

3

Dr. Mayur Kaushik, Subharti Dental College, SVSU

LAYERS OF EPITHELIUM

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PROCESSES MAINTAINING

INTEGRITY

PROLIFERATION

- Division of cells.

- Occurs in basal cell layer.

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DIFFERENTIATION ( KERATINIZATION)

Increased number of tonofilaments &

intercellular junctions.

Production of keratohyaline granules.

Disappearance of nucleus.

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KERATINIZATION

ORTHOKERATINIZED

- No nuclei in stratum corneum.

- Well defined stratum granulosum.

PARAKERATINIZED

- Pyknotic nuclei in stratum corneum.

- Keratohyaline granules dispersed. 8


KERATIN PROTEINS

Numbered in sequence contrary to their molecular weight.

K1 (68 Kd) : Main component of stratum corneum.

K 19 (40 Kd)

OTHER PROTEINS :

- Keratolinin

- Involucrin

- Filaggrin 9


CELLS OF EPITHELIUM

KERATINOCYTES

- Principal cells of epithelium

NON-KERATINOCYTES (Clear Cells)

- Langerhan’s Cells

- Merkel Cells

- Melanocytes

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CELL JUNCTIONS

DESMOSOMES : Connection between

keratinocytes revealed at electron

microscopic level.

Consist of 2 dense attachment plaques

with an intermediate gap.

ZONA OCCLUDENS (tight junctions):

Membranes of adjacent cells appear to be

fused.

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TONOFILAMENTS The morphologic expression of the

cytoskeleton of keratin proteins.

Radiate in a brushlike fashion from the

attachment plaques into the cytoplasm of

the cells.

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KERATOHYALINE GRANULES

Present in stratum granulosum

KERATINOSOMES /

ODLAND BODIES

Present in uppermost cells of stratum

spinosum.

Modified lysosomes which contain acid

phosphatase.

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NON - KERATINOCYTES

MELANOCYTES

- Present in basal & spinous layers.

- Synthesize melanin in organelles

called melanosomes.

TYROSINE

DOPA

MELANIN 14


LANGERHAN’S CELLS

- Modified monocytes derived from

bone marrow.

- Function: Immune reaction – antigen

presenting cells to lymphocytes.

MERKEL’S CELLS

- Harbour nerve endings.

- Tactile perceptors.

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BASAL LAMINA

Joins epithelium with underlying

connective tissue.

Thickness : 300-400 A.

PARTS:

1) Lamina lucida

2) Lamina densa

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LAMINA LUCIDA – Towards epithelium &

mainly composed of the glycoprotein –

laminin.

LAMINA DENSA – Towards connective

tissue & contains Type IV collagen.

Function : Permeable to fluids but acts as

a barrier to particulate matter.

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GLYCOGEN

Concentration in normal gingiva is

inversely related to degree of

keratinization & amount of inflammation

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PARTS OF GINGIVAL

EPITHELIUM

ORAL / OUTER EPITHELIUM

SULCULAR EPITHELIUM

JUNCTIONAL EPITHELIUM

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ORAL / OUTER EPITHELIUM

Covers crest & outer surface of marginal

gingiva & attached gingiva.

Majority of areas : Parakeratinized.

Degree decreases with age.

KERATIN PROTEINS :

Orthokeratinized – K1,K2,K10,K12.

Parakeratinized – K19

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ORDER OF KERATINIZATION

PALATE

GINGIVA

TONGUE

CHEEK 21


SULCULAR EPITHELIUM

Thin, non-keratinized squamous

epithelium without rete pegs.

Extends from coronal limit of junctional

epithelium to crest of gingival epithelium.

Lacks st. granulosum & st. corneum &

keratin proteins: K1,K2,K10,K12.

Contains K4 & K13.

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KERATINIZATION OF SULCULAR

EPITHELIUM

Reflection & exposure to the oral cavity.

Complete elimination of bacterial flora

from sulcus.

Local irritation prevents sulcular

keratinization.

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CLINICAL SIGNIFICANCE

Acts as a semi-permeable membrane.

Bacterial products enter gingival tissues.

Tissue fluids from gingival tissues seep

into sulcus.

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GINGIVA MICROSCOPIC FEATURES

Dr. Mayur Kaushik

26


GINGIVA : MICROSCOPY

LAYERS OF EPITHELIUM

PROCESSES : Proliferation /

Keratinization

CELLS : Keratinocytes & Non-

Keratinocytes

PARTS : ORAL , SULCULAR

EPITHELIUM

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JUNCTIONAL

EPITHELIUM

Collar-like band of stratified

squamous non-keratinizing epithelium.

Normal length : 0.25 – 1.35 mm (>500 μm)

Inflammation : 50 – 100 μm.

Formed by confluence of oral epithelium &

reduced enamel epithelium during tooth

eruption. 28


PARTS OF JUNCTIONAL

EPITHELIUM

Attached to tooth surface –

INTERNAL BASAL LAMINA.

Attached to gingival connective tissue –

EXTERNAL BASAL LAMINA.

Junctional Epithelium + Gingival Fibers

DENTOGINGIVAL UNIT 29


RENEWAL OF GINGIVAL

EPITHELIUM

Constant renewal.

Thickness maintained by new cell

formation in basal & spinous cells &

shedding on cell surfaces.

MITOTIC RATE

Buccal Mucosa, Hard Palate

Sulcular , Junctional Epithelium

Marginal , Attached Gingiva

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GINIGIVAL CONNECTIVE TISSUE (LAMINA PROPRIA)

PAPILLARY LAYER

Between epithelial rete pegs

RETICULAR LAYER

Continuous with periosteum

of alveolar bone.

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COMPONENTS OF CONNECTIVE

TISSUE

CELLS

EXTRACELLULAR COMPONENTS

GROUND SUBSTANCE

PROTEOGLYCANS – Hyaluronic Acid,

Chondroitin Sulfate

GLYCOPROTEINS – Fibronectin, Laminin

FIBERS

COLLAGEN (Type I)

RETICULAR (Type IV)

ELASTIC 32


GROUPS OF GINGIVAL FIBERS

GINGIVODENTAL GROUP

TRANSSEPTAL GROUP

GINGIVOPERIOSTEAL

GROUP

CIRCULAR GROUP

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CELLULAR ELEMENTS

FIBROBLASTS : Principal cell type.

Synthesize as well as degrade collagen.

OTHER CELLS :

MAST CELLS

MACROPHAGES

ADIPOSE CELLS

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BLOOD SUPPLY

SUPRAPERIOSTEAL ARTERIES

VESSELS OF PERIODONTAL LIGAMENT

ARTERIOLES FROM CREST OF SEPTA

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LYMPHATICS

SUBMAXILLARY LYMPH NODES

NERVE SUPPLY

NERVES FROM PERIODONTAL LIGAMENT,

LABIAL, BUCCAL & PALATAL NERVES.

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GINGIVA - dental.subharti.orgdental.subharti.org/periodonotics/Gingiva_microscopy.pdf- Present in...

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