dentinogingival junction

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The gingival sulcus

is an area of potential space between

a tooth and the surrounding gingival

tissue.

It is lined by two entities:

-Apically by the gingival fibers of

connective tissue attachment .

_Coronally by free gingival margin .

The gingival sulcus

Under normal conditions the depth

of the sulcus is variable.45% of all

measured sulci are below 0.5 mm

,the average sulcus is 1.8mm

the shallower sulcus is the more

likely that the gingival margin is

not inflamed

THE SULCULAR EPITHELIUM

Its stratified squamousepithelium ,non keratinized .Para keratinized that iscontinuous with the oralepithelium and lines thelateral surface of the sulcus .

Its lacks epithelial ridges soforms a smooth contact withlamina properia

THE SULCULAR EPITHELIUM

Apically it overlaps the

coronal border of the

junctional epithelium

this epithelium shares many

of the characteristics of oral

epithelium including good

resistance to mechanical

forces and relative

impermeability to fluid and

cells

the junctional epithelium

Its the stratified non keratinizingepithelium that surround the tooth likea collar .

its attached by one broad surface tothe tooth and by the other to thegingival connective tissue

The junctional epithelium has twobasal lamina:

oOne that faces the tooth (internal basallamina )

oThe other faces connective tissue(external basal lamina)

the junctional epithelium

The desquamative sheddingsurface of the junctional epitheliumis located at its coronal end whichalso forms the bottom of thegingival sulcus

The junctional epithelium is morepermeable than oral or sulcularepithelium It serves as theperferential route for the passage ofbacterial products from the sulcus into connective tissue into the sulcus

THE JUNCTION EPITHELIUMTHE SULCULAR EPITHELIUM

1. It is epithelium that surroundthe tooth like a collar .

2. It is more permeable than oral orsulcular epithelium It serves asthe perferential route for thepassage of bacterial productsfrom the sulcus in to connectivetissue and fluid and cells from C.Tinto the sulcus

1. It is continuous with the oralepithelium and lines the lateralsurface of the sulcus .

2. It characterized by goodresistance to mechanical forcesand relative impermeability tofluid and cells

Development of the junctioanal epithelium

As the erupting tooth approaches the

overlying epithelium, the external

cells of the reduced enamel

epithelium proliferate, causing the

epithelial covering of the enamel to

thicken.

Development of the junctioanal epithelium

Proliferation of the externel cells

of the reduced enamel epithelium

begins around the cusp tips and

slowly progresses toward the

cervix of the tooth

Development of the junctioanal epithelium

proliferating cells eventually displace

any remaining reduced ameloblasts, thus

replacing the relatively inert reduced

enamel epithelium with an epithelial

collar of cells with a high turnover

rate. This collar of cells with a high

turnover rate is the early junctional

epithelium.

Eventually, the entire reduced enamel

epithelium will become replaced by

junctional epithelium.

Development of the junctioanal epithelium

After accomplishing of amelogenesis(protective stage) the ameloblast secreteor leave structure less material on enamelsurface primary enamel cuticle .

The enamel organ becomes reduced inthickness (reduced enamel epithelium )and function as aprotection againstcontact with connective tissue ,to inhibitcementum deposition or enamelresorption

The reduced enamel epi theliumconsists of two layers

1-the reduced ameloblast

2-remnant of the dental organ

Development of the junctioanal epithelium

The ameloblast develop hemidesmosomesto attach the reduced enamel epithelium tothe surface of the enamel at the time oferuption the reduced enamel epitheliumsecrete desmolytic enzymes causingdegenerating of the of the c.t presentbetween it and the oral mucosa (desmolyticstage of amelo blasts )

The outer layer of the reduced enamelepithelium and the cells of the oralepithelium proliferate into the degeneratedc.t. to form amass of cells over the eruptingtooth the epithelial plug.

Development of the junctioanal epitheliumCell death in th middle portion of plug cause formation of epithelial lined canalthrough which tooth will erupt with out hemorrhage

Once the tip of the crown appear in the oral cavity reduced enamel epithelium willbe called primary attached epithelium

And the the shallow groove present between the tooth and the gingiva is calledGINGIVAL SULCUS

The cells of primary attached epithelium (PAE) originate from reduced enamelepithelium and attached to tooth by primary enamel cuticle

When primary attachment epithelium is replaced by oral epithelium its calledsecondary attached epithelium that attaches by secondary enamel cuticle.

Secondary enamel cuticlePrimary enamel cuticle

1. Binds secondary attachedepithelium to the enamel surface

2. It is formed finally when the teeth erupt

1. Binds primary attached epitheliumto the enamel surface

2. It is formed initially at theprotective stage

Secondary attached epi.Primary attached epi.

1. It is Primary attachmentepithelium replaced by oralepithelium

2. attached by secondary enamelcuticle

1. originate from reduced enamel epithelium

2. attached to tooth by primary enamel cuticle

Shift of the dento gingival junction

The dentogingival junction is an anatomicaland functional interface between the gingivaand the tooth structure.

Dento gingival junction is the region wherethe tooth is attached to gingival and is formas soon as the tooth erupts in the oral cavity.

It provides attachment of the gingiva to theenamel surface via hemidesmosomes

with time the position of the gingiva of thesurface change

Shift of the dento gingival junction

Components

1. Epithelial component is derived fromreduced dental (enamel) epitheliumand oral epithelium.

2. The connective tissue component isderived from the lamina propria of theoral mucosa.

The attachment of the functionalepithelium to the tooth is reinforced withthe gingival fibers, which brace the gingivalagainst the tooth surface.

Dento gingival junction

Shift of the dento gingival junction

almost entire enamel is covered byepithelium when the tip of the enamelfirst emerge through the mucous

membrane of the oral cavity .

the eruption of teeth continuous until itreach the plan of occlusion.

the firmness strength of the dentinogingival junction beacause of connectivetissue attachment of epithelium toenamel is not week as the crowncontinuous on to the oral cavity

the attachment separate from the enamelsurface gradually

Shift of the dento gingival junction

when the tip of the enamel first emerge through the mucous membrane of

the oral cavity . one third to one fourth of enamel is still covered by the gingiva

The actual movement of teeth towards occlusal plane called acitveeruption

The separation of primary attached epithelium from the enamel

surface called passive eruption

THE SHIFT OF DENTINO GINGIVAL JUNCTION INVOLVE

First stage

Occur in the primary teeth till one year

before shedding in the permanent teeth

20_30.

the bottom of the sulcus present on

the enamel and the apical end of the

AE on the cement enamel junction.

Clinical crown is less than anatomical

crown.

THE SHIFT OF DENTINO GINGIVAL JUNCTION INVOLVE

Second stage

Occur till age of the 40 or even later.

The bottom of the sulcus still present

on the enamel and the apical end of the

AE on cementum.

the clinical crown is less than

anatomical crown.

THE SHIFT OF DENTINO GINGIVAL JUNCTION INVOLVE

Third stage

It is unhealthy condition.

The bottom of the sulcus present at the

CEJ and the apical end at cementum.

The clinical crown equal to the

anatomical crown.

THE SHIFT OF DENTINO GINGIVAL JUNCTION INVOLVE

Fourth stage

It is unhealthy condition.

From 60 years later .

The bottom of the sulcucs and apical

end on the cementum.

The clinical crown is longer than

anatomical crown

•As the original sulculardepth increase and apicalmigration of the junctionalepithelium simultaneouslytack place.

•pathosis has occurred to havetrue periodontal pocketaprobing measurment of 4mm must be clinicallyevidence.

The periodontal pocket

It results in:1. A bluish-red vertical zone from

the gingival margin to thealveolar mucosa.

2. Gingival bleeding.3. Suppuration & tooth mobility4. And diastema formation.

symptoms such as localizedpain or pain "deep in the bone"are suggestive of the presenceof periodontal pockets

Done by:Ban mohammed