**Question:** True about dentition –

A. Dentition is the process of development and maintenance of teeth in vertebrates.
B. Teeth are made of enamel and dentin, with pulp chambers containing nerves and blood vessels.
C. The permanent dentition begins to emerge in humans around the age of 6 years, and continues until around 21 years old.
D. Teeth are essential for digestion and chewing food.

**Answer Explanation:**

**Core Concept:** Dentition refers to the process of tooth development and maintenance in vertebrates, which includes the formation, eruption, and replacement of teeth.

**Why the Correct Answer is Right:**

Dentition is a crucial aspect of vertebrate biology, as it allows for proper mastication (chewing) of food, which is essential for efficient digestion. Teeth are composed of enamel (the hard, white outer layer) and dentin (the inner, yellowish substance), with pulp chambers containing blood vessels and nerves. The process of dentition involves multiple stages, including tooth formation, eruption, and replacement.

**Why Each Wrong Option is Incorrect:**

A) This option is incorrect as dentition is a broader concept encompassing the entire process of tooth development and maintenance.

B) While teeth do contain enamel, dentin, and pulp chambers, this statement is too specific and does not encompass the true essence of dentition.

C) This statement is partially correct; however, the process of dentition continues throughout an individual's life, not just until around 21 years old. Permanent teeth continue to be formed into the third decade of life and may be replaced due to caries or trauma throughout life.

**Clinical Pearl:** Dentition is a critical aspect of oral health, ensuring proper chewing, digestion, and overall oral health. Understanding the stages and components of dentition helps in diagnosing and treating dental issues effectively.