SUBMITTED BY MIDHILA MADHU

REG NO: 13971020SUBMITTED TOLESHA .M.SASSISTANT PROFESSOR IN NATURAL SCIENCE

Teeth are small, calcified, hard, whitish structures found in the mouth for mechanically breaking down items of food by cutting and crushing them.

They are among the most distinctive features of mammals.

The three main parts are:

Crown

Neck

Root

Part of the teeth above gum.

Outermost covering of crown is enamel.

Enamel is the hardest material in the body.

Part of the teeth between crown and root.

Inside the neck, a cavity is seen and it is the pulp cavity.

Blood vessels and nerve fibres are seen inside the pulp cavity.

Tissues of teeth get nourishment through these blood vessels.

Part of teeth seen inside the gum.

Material that fixes teeth to the socket of jaw bone is cement.

Teeth is made of dentine.

It is made up of living tissues.

It is a hard calcium rich material.

Less harder than enamel.

It disintegrate easily.

Four types of teeth.

They are

a) Incisors

b) Canines

c) Premolars

d) Molars

Flat crown.

Single root.

Helps in cutting and biting.

Pointed crown.

Single root.

Helps in holding and tearing.

Two ridges in crown.

One or two roots.

Helps in chewing and grinding.

Two or three ridges in crown.

Two or three roots.

Helps in chewing and grinding.

The number of teeth of each type is written as a dental formula for one side of the mouth, or quadrant, with the upper and lower teeth shown on separate rows.

In each set, incisors (I) are indicated first, canines (C) second, premolars (P) third, and finally molars (M), giving I:C:P:M.

HUMANS - 2/2 :1/1 :2/2 :1/1

LION - 3/3 :1/1 :3/2 :1/1

COW - 0/3 :0/1 :3/3 :3/3

CAT - 3/3 :1/1 :3/2 :1/1

FOX - 3/3 :1/1 :4/4 :2/3

PIG - 3/3 :1/1 :4/4 :3/3

RABBIT - 2/1 :0/0 :3/2 :3/3

RAT - 1/1 :0/0 :0/0 :3/3.

Plaque

Plaque is a biofilm consisting of large quantities of various bacteria that form on teeth. If not removed regularly, plaque buildup can lead to periodontal problems such as gingivitis.

Streptococcus mutans is the most important bacterium associated with dental caries.

Certain bacteria in the mouth produce lactic acid, which dissolves the calcium and phosphorus in the enamel.This process, known as"demineralisation", leads to tooth destruction.

Oral hygiene is the practice of keeping the mouth clean and is a means of preventing dental caries, gingivitis, periodontal disease, bad breath and other dental disorders.

Brush your teeth twice in a day.

Regular dental check up is also recommended.

A.R.Ten Cate(1998), Oral histology:development, structure and function, 5th edition, mosby year book

Clemente(1987), Anatomy,a regional atlas of the human body, ISBN 0-8067-0323-7

Johnson nad Clarke(1998), Biology of human dentition

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