Question

What is the dental formula

Answer 1

Answer:

A method of describing the number and arrangement of teeth in man and animals using letters and figures. It is written as an expression of the number of each type of tooth in one side of the upper jaw over the number of teeth in one side of the lower jaw. The letters correspond to the type of teeth (I = Incisor, C = Canine, P = Premolar, M = Molar). Humans have two dental formulae, one for the primary dentition and one for the permanent dentition. The dental formulae for different animals varies according to diet and function.

Dental formulae of humans and some animals

Species

Dental formula

Total number of teeth

Human (primary dentition)

I 2/2 C1/1 M2/2

20

Human (secondary dentition)

I 2/2 C 1/1 P 2/2 M 3/3

32

Dog

I 3/3 C 1/1 P 4/4 M 2/3

42

Horse

I 3/3 C 1/1 P 4/4 M 3/3

44

Sheep

I 0/3 C 0/1 P 3/3 M 3/3

32

Rat

I 1/1 C 0/0 P 0/0 M 3/3

16

Answer 2

Do you know? In mammals especially, the number of teeth in both the jaws varied with respect to their food habit. However, it is constant for a particular species.

When we represent the number of teeths according to their kind by any sort of equation, it is known as Dental Formula.

Now how to write the formula?

It is the formula showing the no. of teeths in one half of the upper/lower jaw.

It is separated (i.e. upper and lower jaw) by a horizontal line which is similar to that of a fraction in mathematics.

The no. of teeth shown in the formulae multiplied by 2, gives the total no. of teeth in a species.

Dental formula of Human.

CHILD (milk teeth) - 2 1 0 2 2 1 0 2

ADULTS - 2 1 2 3 2 1 2 3

Here:

Here you can see teeth in upper half jaw is 2 + 1 + 0 + 2 = 5. The total no. of teeth in upper jaw is 5 × 2 = 10. And similarly total no. of teeth in child = 10 × 2 ( both jaws) = 20.

In this way, we can find the total no. of teeth in all organisms by the help of given Dental Formula.

Dental formula for more animals:

Dog - 3 1 4 2 3 1 4 3

Cat - 3 1 3 1 ∣ 3 1 2 1

Cow - 0 0 3 3 ∣ 1 0 2 3

Elephant - 1 0 0 0 0 0 0 3

Note!!

The no. is arranged with correspondence with the kind of teeth in order of Incisors, Cannines, Pre molars, Molars in one half jaw in each row.