Teeth and their structure - Class 4 Notes & Olympiad Questions

Teeth

Teeth are hard, calcified structures that are found in our mouths. They play an important role in helping us chew and break down our food, speak clearly, and maintain the structure of our faces.

Sets of Teeth

a) We actually have two sets of teeth in our lifetime. The first set is called "temporary teeth" or "milk teeth," and the second set is called "permanent teeth" or "adult teeth."
b) Most people have 20 milk teeth, which start to come in when we are about six months old. These teeth are smaller and not as strong as adult teeth.
c) Around the age of six, our baby teeth start falling out, and our permanent teeth begin to come in.
d) We get a total of 32 permanent teeth, which are stronger and bigger than baby teeth. These teeth are meant to last us for the rest of our lives if we take good care of them.

Difference between Temporary teeth and Permanent teeth

Types of Teeth

There are four main types of teeth: incisors, canines, premolars, and molars.

1. Incisors

a) These are the sharp, flat teeth at the front of our mouths.
b) We have four incisors on the top and four on the bottom.
c) Incisors help us bite into our food.

2. Canines

a) These are the pointy teeth next to our incisors.
b) We have two canines on the top and two on the bottom.
c) Canines help us tear and grip our food.

3. Premolars

a) These are the flat teeth behind our canines.
b) We have four premolars on the top and four on the bottom.
c) Premolars help us crush and grind our food.

4. Molars

a) These are the big, flat teeth at the back of our mouths.
b) We have six molars on the top and six on the bottom.
c) Molars also help us crush and grind our food.

Structure of a Tooth

A tooth has three main parts:

1. Crown

a) This is the part of the tooth that you can see in your mouth.
b) It's the white, hard part that helps us chew.
c) The crown is covered in a tough substance called enamel, which is the hardest material in our bodies.

2. Dentin

a) This is the layer beneath the enamel.
b) Dentin is not as hard as enamel, but it's still strong.
c) It gives the tooth its shape and supports the enamel.

3. Root

a) This is the part of the tooth that is hidden below the gumline.
b) The root helps hold the tooth in place in the jawbone.

Inside the tooth, there is a soft, living part called the pulp. The pulp contains blood vessels and nerves that keep the tooth healthy and alive.

Tooth Decay and Care

a) Tooth decay happens when the bacteria in our mouths combine with the sugars from the food we eat to create acids.
b) These acids can damage the hard outer layer of our teeth called enamel and create tiny holes, which are called cavities.
c) If left untreated, cavities can become bigger and cause pain or infection.

Taking care of your teeth is essential to prevent tooth decay. Some important tips for good oral hygiene are:

1. You should brush your teeth at least twice a day, using a soft-bristled toothbrush and toothpaste.
2. Flossing is important because it helps remove food particles between the teeth, where toothbrush can't reach.
3. Try to limit sugary and sticky foods, like candies, cookies, and sodas. These foods can contribute to tooth decay. Instead, eat more fruits, vegetables, and dairy products like milk and cheese, which are good for your teeth.
4. Regular dental visits help keep your teeth healthy and catch any problems early. The dentist can examine your teeth, clean them, and check for any signs of decay or other oral health issues.