Dentinogingival junction

periodontics \ oral histology

1. dento -gingival junction

2. 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 .

3. 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

4. THE SULCULAR EPITHELIUM Its stratified squamous epithelium ,non keratinized . Para keratinized that is continuous with the oral epithelium and lines the lateral surface of the sulcus . Its lacks epithelial ridges so forms a smooth contact with lamina properia

5. 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

6. the junctional epithelium Its the stratified non keratinizing epithelium that surround the tooth like a collar . its attached by one broad surface to the tooth and by the other to the gingival connective tissue The junctional epithelium has two basal lamina: One that faces the tooth (internal basal lamina ) The other faces connective tissue (external basal lamina)

7. the junctional epithelium The desquamative shedding surface of the junctional epithelium is located at its coronal end which also forms the bottom of the gingival sulcus The junctional epithelium is more permeable than oral or sulcular epithelium It serves as the perferential route for the passage of bacterial products from the sulcus in to connective tissue into the sulcus

8. THE JUNCTION EPITHELIUM THE SULCULAR EPITHELIUM It is epithelium that surround the tooth like a collar . It is more permeable than oral or sulcular epithelium It serves as the perferential route for the passage of bacterial products from the sulcus in to connective tissue and fluid and cells from C.T into the sulcus It is continuous with the oral epithelium and lines the lateral surface of the sulcus . It characterized by good resistance to mechanical forces and relative impermeability to fluid and cells

9. 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. 

10. 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

11. 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.

12. Development of the junctioanal epithelium After accomplishing of amelogenesis (protective stage) the ameloblast secrete or leave structure less material on enamel surface primary enamel cuticle . The enamel organ becomes reduced in thickness (reduced enamel epithelium ) and function as aprotection against contact with connective tissue ,to inhibit cementum deposition or enamel resorption The reduced enamel epi thelium consists of two layers 1-the reduced ameloblast 2-remnant of the dental organ

13. Development of the junctioanal epithelium The ameloblast develop hemidesmosomes to attach the reduced enamel epithelium to the surface of the enamel at the time of eruption the reduced enamel epithelium secrete desmolytic enzymes causing degenerating of the of the c.t present between it and the oral mucosa ( desmolytic stage of amelo blasts ) The outer layer of the reduced enamel epithelium and the cells of the oral epithelium proliferate into the degenerated c.t . to form amass of cells over the erupting tooth the epithelial plug.

14. Development of the junctioanal epithelium Cell death in th middle portion of plug cause formation of epithelial lined canal through which tooth will erupt with out hemorrhage Once the tip of the crown appear in the oral cavity reduced enamel epithelium will be called primary attached epithelium And the the shallow groove present between the tooth and the gingiva is called GINGIVAL SULCUS The cells of primary attached epithelium (PAE) originate from reduced enamel epithelium and attached to tooth by primary enamel cuticle When primary attachment epithelium is replaced by oral epithelium its called secondary attached epithelium that attaches by secondary enamel cuticle.

15. Secondary enamel cuticle Primary enamel cuticle Binds secondary attached epithelium to the enamel surface It is formed finally when the teeth erupt Binds primary attached epithelium to the enamel surface It is formed initially at the protective stage Secondary attached epi . Primary attached epi . It is Primary attachment epithelium replaced by oral epithelium attached by secondary enamel cuticle originate from reduced enamel epithelium attached to tooth by primary enamel cuticle

16. Shift of the dento gingival junction The dentogingival junction is an anatomical and functional interface between the gingiva and the tooth structure. Dento gingival junction is the region where the tooth is attached to gingival and is form as soon as the tooth erupts in the oral cavity. It provides attachment of the gingiva to the enamel surface via hemidesmosomes with time the position of the gingiva of the surface change

17. Shift of the dento gingival junction Components 1. Epithelial component is derived from reduced dental (enamel) epithelium and oral epithelium. 2. The connective tissue component is derived from the lamina propria of the oral mucosa. The attachment of the functional epithelium to the tooth is reinforced with the gingival fibers, which brace the gingival against the tooth surface.

18. Dento gingival junction

19. Shift of the dento gingival junction almost entire enamel is covered by epithelium when the tip of the enamel first emerge through the mucous membrane of the oral cavity . the eruption of teeth continuous until it reach the plan of occlusion. the firmness strength of the dentino gingival junction beacause of connective tissue attachment of epithelium to enamel is not week as the crown continuous on to the oral cavity the attachment separate from the enamel surface gradually

20. 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 acitve eruption The separation of primary attached epithelium from the enamel surface called passive eruption

21. 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. HEALTHY

22. 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. HEALTHY

23. 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. UNHEALTHY

24. 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 UNHEALTHY

25. The periodontal pocket As the original sulcular depth increase and apical migration of the junctional epithelium simultaneously tack place. pathosis has occurred to have true periodontal pocket aprobing measurment of 4 mm must be clinically evidence.

26. The periodontal pocket It results in: A bluish-red vertical zone from the gingival margin to the alveolar mucosa. Gingival bleeding. Suppuration & tooth mobility And diastema formation. symptoms such as localized pain or pain "deep in the bone" are suggestive of the presence of periodontal pockets

27. Done by: Ban mohammed