Oral Mucus Membrane Dentogingival Junction

Histological Structure of Junctional Epithelium

• Junctional epithelial cells are connected by few desmosomes and have large intercellular spaces, allowing for the passage of crevicular fluid and defense cells.
• Healthy gingival tissue may exhibit neutrophils in the intercellular spaces, indicative of its protective role.

Histology of Dento-Gingival Junction

• Basal cell layer consists of superficial flat cells, hemidesmosomes, and external basal lamina.
• Lamina propria is separated from the epithelial cells by a smooth basement membrane.
• Internal basal lamina is in contact with the tooth, and external basal lamina is in contact with the lamina propria.

Attached Apparatus (Epithelial Attachment)

• Junctional epithelial cells attach to the enamel or cementum by hemidesmosomes and a basal lamina produced by the epithelial cells.

Gingival Recession (Passive Eruption)

• Gingival recession occurs in two stages: first stage until the age of 1 year in primary teeth and until 20-30 years in permanent teeth, and second stage persisting up to 40 years.

Oral Mucous Membrane: Dentogingival Junction

• The junctional epithelium is unique in having two basal laminae.

Histogenesis of Dento-Gingival Junction

• Desmolytic enzymes break down the epithelial plug, forming the primary D.G.J.
• Reduced dental epithelium forms the primary attachment epithelium, which later forms the secondary attachment epithelium.

Gingival Sulcus and Dentogingival Junction

• Gingival sulcus is lined by non-keratinized stratified squamous epithelium, which is thinner than epithelium of gingiva and lacks epithelial ridges.

Histology of Dento-Gingival Junction

• The junctional epithelium is 15-30 cells thick coronally and 1-3 cells thick apically.
• It consists of two zones: a single cell layer of cuboidal cells (stratum germinativum) and several layers of flattened cells.
• The junctional epithelium has a high rate of turnover (5-6 days).
• It is initially derived from the rapidly replaced reduced enamel epithelium.