Enamel Development and Amelogenesis

What is the approximate time it takes to complete the crown of a permanent tooth?

10 years
7 years
5 years (correct)
2 years

What is the role of ameloblasts in amelogenesis?

To produce mature enamel directly
To remove water, proteins, and other organic materials
To grow hydroxyapatite crystals
To produce a special protein scaffold (correct)

What happens during the maturation stage of amelogenesis?

Ameloblasts remove water, proteins, and other organic materials (correct)
The tooth crown is fully formed
Hydroxyapatite crystals start to grow
Ameloblasts produce a special protein scaffold

What is the main component that grows in the protein scaffold during amelogenesis?

Hydroxyapatite crystals (B) Signup and view all the answers

What is the function of the Tomes' processes in enamel formation?

To shape the enamel rod (C) Signup and view all the answers

What is the percentage of time taken up by the maturation stage in the process of producing a full crown of enamel?

Up to two thirds (C) Signup and view all the answers

At which stage of tooth development does the enamel organ form?

Bud stage (A) Signup and view all the answers

What is the primary function of the cells in the inner enamel epithelium during the morphogenetic phase?

To shape the future crown (D) Signup and view all the answers

During which phase do the inner enamel epithelium cells differentiate into ameloblasts?

Histodifferentiation phase (A) Signup and view all the answers

At approximately which week of embryonic development does the bell stage occur?

11th week (D) Signup and view all the answers

What is the term for the process of enamel development?

Amelogenesis (D) Signup and view all the answers

What is the function of the stellate reticulum during tooth development?

To regulate the movement of cells and ions (D) Signup and view all the answers

What is the main function of Tomes' process in amelogenesis?

To stagger protein secretion into two parts, forming prisms and interprismatic regions (C) Signup and view all the answers

What is the result of the stellate reticulum collapsing during the secretory phase?

The surrounding vascular tissue moves closer to the ameloblasts (D) Signup and view all the answers

What is the percentage of final enamel hardness achieved during the secretory phase?

30% (B) Signup and view all the answers

What do ameloblasts secrete during the secretory phase?

Enamel matrix proteins (A) Signup and view all the answers

What is the main component of enamel matrix proteins?

Amelogenin (B) Signup and view all the answers

What is the function of the stratum intermedium during the secretory phase?

To support the ameloblasts (D) Signup and view all the answers

What happens to the reduced enamel epithelium as a tooth erupts?

It merges with the oral epithelium (C) Signup and view all the answers

What is the function of the junctional epithelium?

To act as a seal from the oral environment (D) Signup and view all the answers

What remains of the reduced enamel epithelium after a tooth erupts?

Only the cervical portions remain (C) Signup and view all the answers

What do ameloblasts secrete during the late maturation stage of amelogenesis?

Enamel matrix protein-digesting enzymes (B) Signup and view all the answers

What happens to most of the reduced enamel epithelium during tooth eruption?

It gets destroyed (B) Signup and view all the answers

What is the effect of ameloblasts removing water from the developing enamel during the late maturation stage?

Increasing the mineral content of the maturing tissue (A) Signup and view all the answers

What is the fate of the cervical portions of the reduced enamel epithelium?

They become the junctional epithelium (D) Signup and view all the answers

At which stage of amelogenesis is enamel most susceptible to fluoride and tetracycline?

Late maturation stage (B) Signup and view all the answers

What is the function of the reduced enamel epithelium?

To protect and cover the outer surface of the enamel until tooth eruption occurs (D) Signup and view all the answers

What is the relationship between the reduced enamel epithelium and the oral epithelium during tooth eruption?

They merge together (C) Signup and view all the answers

What is the characteristic of ameloblasts during the late maturation stage of amelogenesis?

They cycle between the early and late maturation stages repeatedly (B) Signup and view all the answers

What occurs after the completion and full maturation of the enamel?

The enamel organ collapses into a dense covering of epithelium (D) Signup and view all the answers