Page 57 - ACTIVE SCIENCE 4 TOC

Milk teeth are also known by temporary teeth. These

teeth start falling one by one between the age of 6 and
12. Thereafter, a new set of teeth starts developing

in their place. This set has about 32 teeth, 16 in the
upper jaw and 16 in the lower jaw. This set of teeth

is known as permanent teeth. It lasts long until the
old age.

Structure Of Teeth

Teeth are held in the socket of the pink-coloured gums.
There are three parts of a tooth. Temporary Teeth

• Crown : The part above the gum which is

visible is called the crown.

• Neck : The part which is below the crown, touching the gum is called the

neck.

• Root : The part of the tooth inside the gum is known as the root.

Enamel is the hardest part of
the body. It is the hard outer Enamel

covering of the tooth which is Dentine
white in colour. Crown (above gum)

The layer below the enamel Gum
is called dentine. There is Pulp cavity
pulp below the dentine. The Neck Tough fibres

soft part of the tooth is called
the pulp. It is connected to Cement

the gum through a hole in the Nerve
root. There are blood vessels Root (embedded in bone) Blood vessels
and nerves inside it. Jaw bone

Structure of tooth
Types Of Teeth
There are four types of teeth in the permanent set – incisors, canines, premolars

and molars.

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