 Hello everyone, welcome back to a new session in dentistry and more today's topic is Jinjeva So this video covers the Jinjeva, its parts, its fibers, various functions in detail. So let's see the details of Jinjeva. So as per definition, Jinjeva, it is a part of oral mucosa that covers the alveolar process of jaws and surrounds the neck of the teeth. So as we all know, it is the covering of alveolar bones and surrounds the neck of the teeth. It has got basically two parts, one is marginal Jinjeva and attached Jinjeva. Marginal Jinjeva is a free Jinjeva which is not attached to the teeth. We can see just around the teeth which is forming a small groove or small sulcus around the teeth, that is marginal Jinjeva and it is also known as free Jinjeva because it is not attached, it is free to move or it is flexible in nature. So that is marginal Jinjeva and attached Jinjeva which is attached to the underlying bone. So it is not movable type, it is firmly attached to the underlying alveolar bone and this attached Jinjeva and marginal Jinjeva which is separated by a groove known as free Jinjeva groove. So this is the marginal Jinjeva, this blue color and the red color is attached Jinjeva which is attached to the bone and this is alveolar mucosa. So marginal Jinjeva basically has two parts, that is Jinjeva sulcus and intertental Jinjeva. So this is a Jinjeva sulcus you can see, this is a sulcus between the Jinjeva and teeth. So it is a V shaped crevice which is 1.8 mm basic depth that is 0 to 6 mm in range which has got crevicular fluid or GCF and the probing depth is usually 2 to 3 mm. So this is a Jinjeva and alveolar bone, so this is alveolar bone. So we have attached Jinjeva from here to here, this is alveolar mucosa, the same picture I am showing here, this is a frontal view, this is a side view. So alveolar mucosa attached Jinjeva. So we have free Jinjeva, this is a Jinjeva sulcus or crevicular area and it is separated by free Jinjeva groove or the marginal Jinjeva groove. From here to here it is attached Jinjeva which is firmly attached to the bone and from that to lower part of alveolar mucosa. So next we have intertental Jinjeva, so that is between the two teeth, okupai Jinjeva embrasure which is site of initializations which is pyramidal anterior region and flattened in posterior region which is basically scallop and presence of intertental call. So there will be a valley space between the anterior posterior that is a front and back region, there will be a valley space or a shallow space which is known as call and marginal Jinjeva which is a collar like terminal edges which is free to move which is 1.5 to 2 mm wide. This is marginal Jinjeva and which is a sluice way in mastication and forming sulcus between tooth and Jinjeva, ok. So this is a sulcus which is formed by marginal Jinjeva and tooth whereas the attached Jinjeva which is a functional mucosa which is very firm, resilient and tightly bound to alveolar mucosa which is spale and pink which is stippled. Stippling is the alternate protrusions seen on the Jinjeva surface which is giving it an orange peel appearances. So the epithelium and connective tissue interdigitation gives that particular stipple appearances. Stippling is a good sign for Jinjeva and if the stippling is absent there will be some pathology involved. So in attached Jinjeva the maxillary incisor region is ranging between 3.5 to 4.5 whereas in molar it is 1.9 mm. In mandibular region it is 3.3 to 3.9 and in molar mandibular 1.8 mm. So what are the clinical huges? The basic color is coral pink color. Coral pink means the coral reefs. The pink color we have various shades of pink. The pink color which is seen in the coral reefs, the seaside coral reefs that's why it's got that peculiar name coral pink. So the pink color which is seen in the coral reefs. The size is 0.2 mm, marginally Jinjeva and sorry 0 to 2 mm marginally Jinjeva and 0 to 9 mm attached Jinjeva. Contour is scalloped and firm and resilient consistency and stipple texture. So it is developing when there is oral epithelium it joins with the reduced enamel epithelium. So once the enamel is laid down the epithelium which covers the tooth is known as reduced enamel epithelium which joins with oral epithelium and becoming junctional epithelium. So this is a junctional epithelium so this is a tooth and the oral epithelium and reduced enamel epithelium which is present here become junctional epithelium. And we have another type of epithelium which is known as sulcular epithelium which is seen in the Jinjeval crevice and also oral epithelium that is epithelium which covers the outer surface of Jinjeva. So that is oral epithelium then the sulcular epithelium and junctional epithelium. Junctional epithelium is fusion of reduced enamel epithelium which was present on the enamel surface after the tooth formation which joins with oral epithelium becoming junctional epithelium. So that is about the basic introduction part its classification marginal and attached Jinjeva, Jinjeval sulcasan endodendral Jinjeva. So now let's see the various epithelium that is oral, sulcular and junctional epithelium of Jinjeva. So moving on to the various epithelial types in Jinjeva the oral epithelium, sulcular epithelium and junctional epithelium. So this is a junctional epithelium, sulcular epithelium and the oral epithelium. So oral epithelium is keratinized, keratinized means we have four layers of epithelium in common the stratum basalis, stratum spinosum, stratum granulosum and stratum corneum. So the level of keratinization increases as it goes higher. So basal layer has cell multiplication and as it goes higher there is more of keratinization happens. So oral epithelium is basically keratinized and stratified in nature and it is also a squamous type. So there is basically three types of keratinization. One is para keratinized which has got 75% of total oral epithelium and the auto keratinized is 15% and non keratinized is 10% and there are various cells of epithelium present. The difference between para keratinized and ortho keratinized it is a level of keratinization. Basically ortho keratinized is the least common form of epithelium found in oral cavity which is associated with masticatory mucosa of heart pilot and attached to Jinjeva and the para keratinized is the most common one and para keratinized most commonly associated with the masticatory surfaces and we have various cells of epithelium. So before that we need to know the basic structure of epithelium. At basal layer we have stratum basal layer where the cell production is happening then stratum spinosum and stratum granulosum and the top layer is stratum corneum where the complete keratinization happens. So the level of keratinization is increasing as it goes higher. At the basal layer the cell multiplication and cell genesis production of cells happening at stratum basal layer. So the organelles and the multiplication mitosis feature when all are present at the deeper layers as it goes at the top layers it becomes more keratinized and nocly and other organelles will be lost and it will be completely keratinized. So we have cells of epithelium that is keratinocytes and non-keratinocytes. Non-keratinocytes is also known as clear cells. So we have keratinocytes which produces keratin and non-keratinocytes which has other functions also known as clear cell. So we have three types of known keratinocytes in oral cavity, melanocytes, langer hand cells and merkel cell. So these are very important commonly asked short notes in exam what is melanocyte, what is langer hand cell and merkel cell. Langer hand cells we have already covered previously. So we have one more cell which is lang hand cells that is different that is seen in pathology tuberculosis is a langer hand cells. So never get confused with lang hands and langer hand cells this is langer hand cells. So the first one is merkel cell. Merkel cell is nothing but which is located in the deeper layer of epithelium and they have a nerve endings and these are connected to adjacent cell by dysmosomes and they have been identified as tactile perceptors. So these are tactile perceptors which is present in the deeper cells and the next one is langer hand cells which are dendroitic cells located among keratinocytes at all supra basal layer. So near the top layer it is present, langer hand cells which are the dendroitic cells and they belong to the mononuclear phagocyte system or also known as these are the reticulo endothelial system. So it belongs to the reticulo endothelial system and which contain elongated granules and are considered macrophages as macrophages with possible antigenic properties. So it has antigenic properties which involves with immunity that is mononuclear phagocytes and the next one is melanocytes which are basically involved in melanin production. Then they are dendroitic cells located in basal and spinous layers which involve in synthesis of melanin in organelles that is pre-melanosomes or melanosomes. These organelles which contain tyrosinase that hydrolytes hydroxylates. So there will be tyrosinase enzymes in these organelles that is melanosomes or pre-melanosomes. So this enzyme which convert tyrosin to dopa that is dihydroxy phenylalanin, phenylalanin will be produced which in term is progressively converted to melanin. So the melanin will be synthesized in organelles that is pre-melanosomes or melanosomes which contain an enzyme monos, tyrosinase which hydroxylates tyrosin to dopa, dihydroxy phenylalanin which in term progressively converted to melanin. So melanin granules are phagocytosed and contained within other cells of epithelium and connective tissue. So it can be seen it as the cells of epithelium and connective tissue. They are called melanophages or melanophores. So melanophages or melanophores are melanin granules which are phagocytosed and contained within various epithelium and connective tissue. So these are the basic cells of gingiva. These are the non-keratinosides it has two types one is keratinoside and non-keratinoside or clear cell melanosides, langurhansels and merkel cell. So melanosides are involved in melanin production, langurhansels has antigenic property, merkel cell is for tactile perceptors is commonly as short nodes, gingiva, epithelium. So now we will see circular and junctional epithelium. So in circular epithelium, so circular epithelium is the this section the blue color okay so this is the orange color is the gingiva epithelium this blue is circular epithelium and this black one which is starting from the cemento enamel junction till here is the junction epithelium okay. So gingiva epithelium we already covered now we are in circular epithelium. circular epithelium which lines the gingiva sulcus so this is the gingiva sulcus so it lines the gingiva sulcus and it is a thin non-keratinoid stratified scoma epithelium without any retepics okay so it does not have any retepics in it so it is basically without any retepics and it extends from the coronal limit of junctional epithelium to the crest of gingiva margin okay. So this is the junction epithelium and its coronal end so it starts from coronal end of junction epithelium to the crest of gingiva margin so this is the gingiva margin to the crest of gingiva margin to the coronal end this is apical end this is a coronal end coronal end of junction epithelium to the crest of gingiva margin okay. It is a semi permeable membrane and it shows many cells with hydropic degeneration and unlike the junction epithelium the circular epithelium is not heavily infiltrated with PMN that is cells which is involved in inflammatory process so it is not very common in circular epithelium so these polymorphonucleus cells which are not very much infiltrated in circular epithelium whereas in junction epithelium is highly infiltrated and it appears to be less permeable in nature whereas a junction epithelium it is consist of a color like band of stratified squamous non-characterized epithelium it is okay the length of junction epithelium from 0.25 to 1.35 millimeter and it is 3 to 4 layer at the beginning and as age goes as a person ages it reaches up to 10 to 20 layers so we have seen it is formed by oral epithelium and reduced enamel epithelium okay so the part of oral epithelium and after tooth formation there is something called reduced enamel epithelium here so it is joined by formed by the combination of reduced enamel epithelium and oral epithelium so it is formed by confluence of these two epithelium and junction epithelium is attached to tooth surface by something known as epithelium attachment and internal basal lamina so this is called internal basal lamina so this is attached to the tooth surface here attached to the tooth surface by internal basal lamina which is a epithelial attachment and it is attached to the ginger well connected tissue by a external basal lamina okay so to the tooth surface it is attached by internal basal lamina and it is attached to the ginger well connected tissue by an external basal lamina so internal basal lamina and also there is something known as external basal lamina. So external basal lamina, so external basal lamina the junction lepithelium is attached to the jeep javel connected tissue whereas internal basal lamina is junction lepithelium attachment to the tooth surface okay and the attachment of junction lepithelium to the tooth is reinforced by the junction javel fibers so there will be junction javel reinforcement so junction javel reinforcement so you know junction javel reinforcement will be there so this is external basal lamina here internal basal lamina here and junction javel fibers reinforces it which raise the marginal junction javel against the tooth surface okay for this reason the junction lepithelium and junction javel fibers collectively known as dendo junction javel unit it is a functional unit okay so junction javel fibers and the junction lepithelium collectively known as dendo junction javel unit which is a functional unit now let's say the functions of junction lepithelium junction lepithelium firmly attached to the tooth surface we know by internal basal lamina which forms an epithelial barrier against the plaque bacteria okay so it acts as a protective barrier against the plaque bacteria and also it allows access of junction javel fluid inflammatory cells and components of the immunologic host events to the junction javel margin so from the junction javel inflammatory cells will be exited to the it is a as we discussed it is highly infiltrated with polymorphal nuclear cells so there will be access of genjavel fluid inflammatory cells and components of immunological defense mechanism through the to the genjavel margin and junction lepithelial cells exhibit rapid turnover rate which contributes to the host parasite equilibrium and rapid repair of damaged tissues so it has basically three functions one is rapid turnover rate which helps for repairing damaged tissues and immune defense there will be infiltrate coming from the fluid to the internal margin and it acts as a barrier against plaque bacteria