vermilian border

1. Vermilion zone: Transitional zone b/n skin & mucous membrane Found only in humans Skin – thick, keratinised epithelium. Blood is visible through the thin parts of the translucent epithelium that gives the red color.

2. Tongue: surface is rough & irregular. body / A 2/3 base/ P 1/3 Develop from different visceral arches. Lingual nerve glossopharyngeal N Papillary lymphatic Filiform papillae: Numerous fine pointed, cone shaped – velvet like appearance Keratinised No taste buds

3. Fungiform papillae: Mushroom shaped Interpersed b/n filiform papillae 2-3 taste buds Circumvillate papillae: V- shaped terminal sulcus , b/n body & base 8-10 no Numerous taste buds Foliate papillae: Posterior lateral surface Presence of taste buds.

4. Taste bud: Small. Ovoid or barrel shaped Extend from basal lamina to the surface of the epithelium. Outer surface - flat epithelial cells with a small opening called TASTE PORE It forms a narrow space lined by SUPPORTING CELLS Arranged like a staves of a barrel. Neuroepithelial cells – receptors of taste stimuli Primary taste sensation sweet, salty, bitter & sour. Sweet – tip, salty- lateral border ( fungi form papillae) – chorda tympani Bitter– middle (CP), Sour– Lateral border ( Foliate.P )– glossopharyngeal .N

5. Gingival sulcus : Space b/n inner aspect of gingiva & tooth Extends from free gingival margin to DGJ Sulcular epithelium / crevicular epithelium Normal GS depth -2mm Periodontal disease. DENTOGINGIVAL JUNCTION: Junction b/n gingiva & tooth Epithelium of gingiva gets attached to the tooth – junctional / attachment .E The union b/n epithelium & tooth is called epithelial attachment.

6. JE- resembles REE Development: Ameloblast after formation of enamel matrix they leave a thin membrane On the surface of enamel PRIMARY ENAMEL CUTICLE. Ameloblasts cells becomes flat cuboid cells – REE Eruption - fusion of PEC & REE. Remnants of PEC – NASMYTH’S MEMBRANE. Tip of crown emerged, the REE termed as PRIMARY ATTCHEMENT EPITHELIUM Margin of gingiva the attachment epithelium is continuous with oral epithelium Tooth erupts – REE (shorter) – forms gingival sulcus .

7. Shift of dentogingival junction: Position of gingiva on the surface of the tooth changes with time. Ist stage: bottom of the gingival sulcus remains enamel & apical end of attachment epithelium at CEJ primary teeth, 20 -30 Y II nd stage: bottom of GS on the enamel & apical end is shifted to the surface of cementum Dissloution of fiber bundles that were anchored in the cervical parts of cementum Above 40 Y

8. IIIrd stage: Bottom of the GS at CEJ & epithelial attachment entirely on the cementum IV stage: Recession of gingiva Entire attachemnt on cementum.