DDS Dental Anatomy and Histology

Question 1

Which layer of enamel is formed first during tooth development?

Accepted Answer

Inner enamel layer

Answer

The inner enamel layer adjacent to the dentinoenamel junction is formed first as ameloblasts begin secreting enamel from that interface outward.

Question 2

What is the primary organic component of mature enamel?

Accepted Answer

Enamelin

Answer

Enamelin constitutes the main organic protein retained in fully mature enamel, whereas amelogenin is largely removed during maturation.

Question 3

The Tome's process is an extension of which cell?

Accepted Answer

Ameloblast

Answer

Tome's process is the apical cytoplasmic extension of the ameloblast that secretes enamel matrix and determines prism orientation.

Question 4

Which type of dentin is produced throughout the life of the tooth in response to normal physiologic stimuli?

Accepted Answer

Secondary dentin

Answer

Secondary dentin is deposited by odontoblasts after root formation is complete and continues slowly throughout the tooth's functional life.

Question 5

The perikymata visible on the crown surface of a tooth correspond to which histologic structure?

Accepted Answer

Striae of Retzius

Answer

Perikymata are the external surface manifestations of the striae of Retzius, representing incremental growth lines in enamel.

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