Oral Mucous Membrane: Dento-Gingival Junction PDF

Oral Mucous membrane: Dento- gingival junction Dr Sandeep Gupta Oral Pathologist Dento-Gingival Junction Histogenesis of Dento-Gingival Junction 1 Desmolytic Epithelial 2 enzymes plug 1ry D.G.J (from 4 3 Re...

Oral Mucous membrane: Dento- gingival junction Dr Sandeep Gupta Oral Pathologist Dento-Gingival Junction Histogenesis of Dento-Gingival Junction 1 Desmolytic Epithelial 2 enzymes plug 1ry D.G.J (from 4 3 Reduced E. E.) 2nd D.G.J. (from oral E.)  Epithelial plug Reduced dental epithelium Primary attachement epithelium Secondary attachement epithelium From gingival epith Gingival Sulcus & Dentogingival Junction  Gingival Sulcus Nonkeratinized stratified squamous epith. Thinner than epith. of gingiva. Lacks epithelial ridges i.e. has smooth interface with lamina propria. Continuous with gingival epith. & attachement epith. All three epithelia have a continuous basal lamina Histology of Dento-gingival junction  Histological structure -Coronally; the junctional epithelium may be 15-30 cells thick, whilst apically it narrows to only 1-3 cells thick. -It consists of two zones; a single cell layer of cuboidal cells (the stratum germinativum) overlying several layers of flattened cells. -The junctional epithelium has a high rate of turnover (in the order of 5-6 days). -It is initially derived from the rapidly replaced reduced enamel epithelium, -The lamina propria shows many capillaries and appears to be more cellular than other parts of the gingiva. -The epithelial cells are separated from the lamina propria by smooth basement membrane.  Histological structure The junctional epithelium cells are joined by few desmosomes and have large intercellular spaces -So crevicular fluid and defense cells can pass across the junctional epithelium. -Healthy gingival tissue may exhibit neutrophils in the intercellular spaces, indicative of its protective role.  Histology of Dento-Gingival Junction Basal cell Superficial layer flat cells Hemidesmosomes External basal Internal lamina basal lamina Lamina propria  The cells of the junctional epithelium immediately adjacent to the tooth attach themselves to the enamel or cementum by hemidesmosomes within the cell and a basal lamina produced by the epithelial cells. This combination of the hemidesmosomes and basal lamina is known as the attached apparatus or epithelial attachment.  --The basal lamina in contact with the tooth is termed the internal basal lamina.  -The other surface of the junctional epithelium in contact with the lamina propria is the normal basal lamina (the external basal lamina). So the junctional epithelium is therefore unique in having two basal laminae. Gingival recession ( Passive eruption) Shift of DGJ First stage: in 1ry teeth till one y. before shedding In permanent: till20-30 y. Second stage: Persist to 40years. Third stage: transitory Fourth stage: gingival recession (pathologic)till loss Stages of passive eruption  Stages of passive eruption First stage Clinical crown Anatomical crown Coronal end (E) Apical end C.E.J. 1 year before shedding in deciduous teeth and in perm. Till 20-30 years. Second stage Clinical crown Anatomical crown Coronal end (E) Apical end (C). Persist till 40 years Third stage Anatomical Clinical crown crown Coronal end (C.E.J.) Apical end (C) Transitory stage  Fourth stage Anatomical crown Clinical crown Coronal end (C) Apical end (C) Persists till the tooth lost On cementum att. Epith. Secret new basal lamina (cemental cuticle) Thank You