Histology of gingiva revision notes quiz

Healthy Gingiva

• Stippled appearance: The healthy gingiva has a distinctive surface texture that resembles an orange peel.
• Knife-edge gingival margins: The margins of the healthy gingiva are sharp and well-defined, forming a distinct line with the tooth surface.

Oral Epithelium

• Stratified squamous epithelium: This is the type of epithelium found in the oral cavity. It consists of multiple layers of cells.
• Keratinized: The outer surface of the free and attached gingiva.
• Extends: The oral epithelium spans from the crest of the gingival margin to the mucogingival junction.
• Rete pegs: These interdigitations between the epithelium and the underlying connective tissue provide strength and support to the gingiva to withstand external forces.
• Protection: Keratinization protects the gingiva from mechanical stress and trauma.
• Layers of keratinized epithelium:
  • Basal cell layer: Composed of cubical cells responsible for cell renewal.
  • Prickle cell layer: Composed of spine-shaped cells.
  • Granular cell layer: Flattened cells with increased keratin.
  • Keratinized cell layer: Flattened, highly keratinized cells.

Sulcular Epithelium

• Non-keratinized stratified squamous epithelium: This type of epithelium faces the tooth surface but is not in contact with the free margin.
• Semi-permeable: Allows gingival crevicular fluid (GCF) to flow from the tissue into the sulcus.
• No rete pegs or keratinized epithelium: This makes the sulcular epithelium more susceptible to bacteria.
• Layers of sulcular epithelium:
  • Basal cell layer: Cubical shaped.
  • Prickle cell layer: Spine-shaped cells.
  • Superficial cell layer: This forms the outer layer of the epithelium.

Junctional Epithelium

• Non-keratinized stratified squamous epithelium: This epithelium tightly joins the gingiva to the tooth.
• Thickness: It ranges from 15-30 cells thick coronally and 4-5 cells thick apically.
• Epithelial cell attachment: Cells are closely packed and joined by desmosomes.
• Hemidesmosomes: Join epithelial cells to the basal lamina.
• Basal lamina: This thin extracellular matrix is essential for attachment to the tooth surface.
• Functions:
  • Attachment: Hemidesmosomes play a crucial role in attaching the gingiva to the tooth.
  • Barrier: It forms a barrier against bacterial penetration.
  • Host response: The junctional epithelium allows GCF to flow, carrying white blood cells and antibodies to defend against infection.

Gingival Connective Tissue

• Lamina propria: Also known as the gingival connective tissue.
• Location: Found both in the free and attached gingiva.
• Function: Provides solidity to the gingiva through its dense network of fibers.
• Attachment: Attaches the gingiva to the cementum of the root and alveolar bone.
• Transportation: Facilitates the transport of water, nutrients, and other substances within the matrix.
• Host response: Plays a role in the immune response.

Supragingival Fibers

• Elastic and collagen fibers: Contribute to the structural integrity and biomechanics of the gingiva.
• Upright position: These fibers help maintain the gingiva in its upright position.
• Force resistance: They act as a brace to withstand various forces in different directions.
• Inflammation: Inflammation can lead to a decrease in fiber density, compromising the structural integrity.

Supragingival Fiber Groups

• Alveologingival fibers: Extend from the alveolar crest to the gingival connective tissue.
• Circular fibers: Encircle the tooth coronally, above the crestal bone.
• Dentogingival fibers: From the cementum, fan into the gingival connective tissue.
• Periosteogingival fibers: Fan from the periosteum.
• Intergingival fibers: Run mesiodistally along the dental arch, linking teeth together.
• Intercircular fibers: Encircle several teeth, connecting them.
• Interpapillary fibers: Located in the interdental papilla, connecting the oral and vestibular papilla.
• Transgingival fibers: Extend from the cementum to the cementoenamel junction (CEJ) and run horizontally, connecting teeth together.
• Transeptal fibers: Extend from the cementum of one tooth to another tooth over the crestal bone.

Histology of gingiva