Histology; enamel & gingiva

<p>By rod sheaths (D)</p> Signup and view all the answers

<p>65° (B)</p> Signup and view all the answers

<p>There are no enamel rods visible (D)</p> Signup and view all the answers

<p>They lose their tomes process (B)</p> Signup and view all the answers

<p>Perpendicular to the surface and parallel to each other (A)</p> Signup and view all the answers

<p>It is more mineralized than the other layers of enamel (D)</p> Signup and view all the answers

<p>It is the last layer formed by ameloblasts (C)</p> Signup and view all the answers

<p>Stratified non-keratinized (B)</p> Signup and view all the answers

<p>Hemi desmosomes (A)</p> Signup and view all the answers

<p>Free gingiva (B)</p> Signup and view all the answers

<p>Every 5-6 days (B)</p> Signup and view all the answers

<p>Gingival sulcus (A)</p> Signup and view all the answers

<p>Stratum Basale (B)</p> Signup and view all the answers

<p>Stratum epithelium (C)</p> Signup and view all the answers

<p>Providing strength (C)</p> Signup and view all the answers

<p>Stratum Granulosum (C)</p> Signup and view all the answers

<p>They degenerate and are shed through desquamation (B)</p> Signup and view all the answers

<p>Hydroxyapatite (A)</p> Signup and view all the answers

<p>5 million - 12 million (D)</p> Signup and view all the answers

<p>It doubles (D)</p> Signup and view all the answers

<p>Hunter-Shreger bands (D)</p> Signup and view all the answers

<p>Cusp areas (D)</p> Signup and view all the answers

<p>Every 5-6 days (C)</p> Signup and view all the answers

<p>Free / marginal / unattached gingiva (D)</p> Signup and view all the answers

<p>It is a V-shaped notch between the tooth and marginal gingiva. (B)</p> Signup and view all the answers

<p>Junctional epithelium (A)</p> Signup and view all the answers

Enamel rods in cross-section have a key-hole shape, enabling close packing. Rod crystals run parallel to the rod's length, while inter-rod crystals are angled at 65 degrees.

Enamel rod heads point towards cusps, tails towards cervical line. This relates to the growing process.

Enamel is mostly hydroxyapatite (96%) with a small amount of organic matter (4%), found within the rod sheath.

Ameloblasts influence enamel crystal formation and angulation through their projections (Tomes processes).

Four ameloblasts contribute to a single enamel rod.

The outer layer of tooth enamel, lacking visible enamel rods.

Structures within enamel, not present in aprysmatic enamel.

More mineralized than other enamel layers.

Ameloblasts (enamel-forming cells) stop forming tomes process and complete formation of the aprysmatic layer.

All hydroxyapatite crystals are formed perpendicular to the surface + parallel to each other, no change in angulation of the crystals.

Thin tissue layer attaching the gum to the tooth, with rapid cell turnover (5-6 days).

Gum tissue types: Free/Marginal (unattached), Attached (to teeth), Interdental (between teeth).

V-shaped space between the gum and tooth.

Specialized cell junctions attaching Junctional Epithelium to tooth.

Gum tissue covering tooth roots and bone.

The oral epithelium, the outer layer of the gingiva, is composed of four distinct layers: the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum.

The stratum basale, the innermost layer of the oral epithelium, is responsible for cell division and renewal. It's attached to the basement membrane.

The stratum spinosum, the second layer, is active in producing proteins like cytokeratins, which provide strength and structural support to the epithelium.

The stratum granulosum is characterized by the presence of keratohyaline granules, which contribute to the formation of keratin.

The stratum corneum, the outermost layer, consists of flat, dead cells that are continuously shed through desquamation.

Enamel is the hard, protective outer layer of a tooth, made mostly of hydroxyapatite crystals. It's the hardest biological tissue in the body.

An enamel rod is the basic building block of enamel, running from the tooth's root (dentin) to its surface. Each tooth has millions of these tiny, tapered structures.

Enamel rods start wider at the enamel surface and narrow down towards the dentin. This difference in diameter is about 2x.

Enamel rods don't grow in straight lines. Their wavy course creates a pattern called Hunter-Shreger bands, which are more pronounced in the chewing surface of teeth.

Gnarled enamel is a special type of enamel with an exaggerated wavy pattern found on the chewing surfaces of teeth.

The part of the gingiva that is not directly attached to the tooth, it's loosely connected to the underlying connective tissue.

The part of the gingiva that is tightly bound to the tooth and the underlying connective tissue.

The triangular-shaped gum tissue that fills the space between two adjacent teeth.