Question

Write a note on the teeth of humans.

Answer 1

1. Teeth are hard structures meant for holding, cutting, grinding, and crushing the food.
2. In human beings, two sets of teeth (Diphyodont) are developed in their lifetime. The first appearing set of 20 teeth called temporary or milk teeth are replaced by the second set of thirty-two permanent teeth, sixteen in each jaw. Each tooth has a root fitted in the gum (Theocodont).
3. Permanent teeth are of four types (Heterodont), according to their structure and function namely incisors, canines, premolars, and molars.
4. The dental formula represents the number of different types of teeth present in each half of a jaw (upper and lower jaw).
5. The types of teeth are denoted as incisors (i), canine (c), premolars (pm), and molars (m). The dental formula is presented as:

For Milk teeth in each half of the upper and lower jaw:
`"2,1,2"/"2,1,2"` = 10 x 2 = 20
For Permanent teeth in each half of upper and lower jaw:

`"2,1,2,3"/"2,1,2,3"` = 16 x 2 = 32
Types of teeth and their functions

Types of teeth	Number of teeth	Functions
Incisors	8	Cutting and bitting
Canines	4	Tearing and piercing
Premolars	8	Crushing, grinding, and mastication
Molars	12	Crushing, grinding, and mastication