Vermilion zone:Transitional zone b/n skin & mucous membraneFound only in humansSkin – thick, keratinised epithelium.Blood is visible through the thin parts of the translucent epithelium that gives the red color.
Tongue: surface is rough & irregular. body / A 2/3 base/ P 1/3Develop from different visceral arches.Lingual nerve glossopharyngeal NPapillary lymphaticFiliform papillae:Numerous fine pointed, cone shaped – velvet like appearanceKeratinisedNo taste buds
Taste bud:Small. Ovoid or barrel shapedExtend from basal lamina to the surface of the epithelium.Outer surface - flat epithelial cells with a small opening called TASTE POREIt forms a narrow space lined by SUPPORTING CELLSArranged like a staves of a barrel.Neuroepithelial cells – receptors of taste stimuliPrimary taste sensation sweet, salty, bitter & sour.Sweet – tip, salty- lateral border ( fungi form papillae) – chorda tympaniBitter– middle (CP), Sour– Lateral border ( Foliate.P)– glossopharyngeal .N
Gingival sulcus:Space b/n inner aspect of gingiva & toothExtends from free gingival margin to DGJSulcular epithelium / crevicular epitheliumNormal GS depth -2mmPeriodontal disease.DENTOGINGIVAL JUNCTION:Junction b/n gingiva & toothEpithelium of gingiva gets attached to the tooth – junctional / attachment .EThe union b/n epithelium & tooth is called epithelial attachment.
JE- resembles REEDevelopment:Ameloblast after formation of enamel matrix they leave a thin membraneOn the surface of enamel PRIMARY ENAMEL CUTICLE.Ameloblasts cells becomes flat cuboid cells – REEEruption - fusion of PEC & REE.Remnants of PEC – NASMYTH’S MEMBRANE.Tip of crown emerged, the REE termed as PRIMARY ATTCHEMENT EPITHELIUMMargin of gingiva the attachment epithelium is continuous with oral epitheliumTooth erupts – REE (shorter) – forms gingival sulcus.
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 YII 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
IIIrd stage:Bottom of the GS at CEJ & epithelial attachment entirely on the cementumIV stage:Recession of gingivaEntire attachemnt on cementum.