Question

An adult has __________ teeth.
A. 20
B. 24
C. 28
D. 32

Answer 1

The teeth are the hard and pointed structures that are present in our mouth or buccal cavity. The teeth help in cutting, chewing, biting, grinding, and masticating food. The number, kinds, arrangement, and structure of teeth in a person is known as dentition.

Complete answer:
Humans have the heterodont type of teeth based on the function. This means that all the teeth look and perform differently. The four different types of teeth as seen in humans are the incisors, canines, molars, and premolars.
The incisors are the flat-shaped teeth that are used for the cutting of food. The canines are sharp and pointed teeth. They are used for tearing the food, usually flesh. The premolars are the bicuspid teeth or teeth with two cusps or depressions in the crown. They are used to chew the food. Lastly, the molars are the tricuspid teeth or teeth with three cusps or depressions in the crown. They are used for grinding the food.
If we see one half of the jaw of an adult human, we observe that there are two incisors, one canine, two premolars, and three molars. This means that there is a total of eight teeth. Moreover, both jaws have an equal number of teeth. Therefore, on multiplying with four we see that there are thirty-two teeth present in the mouth of an adult human.
Thus, based on the above information we can conclude that an adult has 32 teeth.

Hence, the correct answer is an option (D).

Note: The total number of teeth in children that appear up to the age of seven years is twenty. These teeth are also known as milk teeth or deciduous teeth or temporary teeth. These teeth are diphyodont teeth as they appear twice in a lifetime. On the other hand, teenagers have twenty-eight teeth.