The Teeth

Teeth are one of the most important parts of the digestive system.  Unlike animals, humans have to break their food down into smaller pieces in order to be able to swallow the food.

In order for this to happen, the teeth must help with chewing the food by shearing, cutting, and tearing down the food.

The Mouth

The mouth helps this to happen by muscles in the mouth that move the mouth in a chewing motion and the teeth, along with saliva that comes from the salivary glands, moistens the food and the chewing helps to break it down.

Two Sets of Teeth

Humans have two sets of teeth in their lifetime and the adult human has 32 adult teeth.

When someone is a child, they start out with 20 teeth and these teeth are called “milk teeth” because these are the teeth that we have as babies and toddlers.

When we get older, usually around thirteen years old, we grow more teeth and we have 32 teeth that are different shapes and in different positions, all to help us be able to eat. These teeth will last for the rest of your life.

Different Kinds of Teeth

There are four different kinds of teeth that we have, incisors, canines, premolars, and molars.

The incisors – are at the front of the mouth and they are sharp to help you be able to bite down. The incisors help to cut up food into smaller pieces so that we can chew the food.

The canine – are at the corner of the arches.  They are pointed and sharp and they are used to help hold the food and to tear it into smaller pieces.

The premolars – are a flat tooth and the premolars are used for crushing and tearing food.

The molars – are the biggest teeth in our mouth, and they are also flat, like the premolars.  The molars are used to crush, grind, and chew the food.

There are also other teeth called wisdom teeth that are also called third molars.

These third molars normally grow between the ages of 17-21, but this can differ, depending on the person.

What Are Teeth Made of?

Teeth are small structures that are made out of calcified material.  These teeth are found along the jaws of both humans and animals.

The tissue that seals the side of the teeth in order to stop the infection from happening is called the gums.  The teeth are fixed into the jaw bone and they are held in by the gums.

Different Layers

Teeth have three different layers, the living layer, which is called the pulp, the dentin, and the enamel.

The enamel is the hardest material that is inside the body and this coats the teeth to make sure that they are protected.

A layer of tissues that covers the root of the tooth is called the cementum and it is a yellow looking, bone-like tissue that is tough.

The visible part of the tooth is called the crown.  Each tooth has nerves and these nerves help us to know if something is hot or cold.

Root

If the root becomes sensitive, a dentist may make the patient get a root canal.

The root canal will kill the root in the tooth and help it not to be sensitive anymore.

The flesh-like material found between the tooth and the tooth socket is called the periodontal ligament.  This tissue helps to keep the tooth in place in the gums.

Tooth Decay

People that have teeth know that brushing is important, but sometimes, people still get cavities.  A cavity is another name for tooth decay.

Everyone’s mouth has bacteria on their teeth, gums, lips, and tongue and sometimes the bacteria help to break down food, but other times, the bacteria is bad, and it attaches itself to hard surfaces such as the enamel of the tooth.

When this happens, a yellow looking film is produced on the teeth, called plaque. Too much plaque can cause cavities and cause teeth to need to be filled or sometimes even pulled.

This is why it is important to brush your teeth after eating and drinking, especially with sugary foods and drinks.

Keeping Teeth Healthy

It is important to keep teeth healthy since we only have two sets in our entire lives.

If teeth are not brushed or cared for, they will have a buildup of plaque, and this plaque will rot your teeth and cause cavities to form.

Microbes are the small germs of bacteria that grow in the mouth, they can only be seen with a microscope and that is why they are called microbes.

Microbes feed on the food particles.  Viruses, bacteria, fungus, and protozoa are the four different microbes that are found in the teeth.

Calcium and Bacteria

Calcium helps to keep teeth strong.

Teeth Facts for Kids

• A human child has 20 teeth which will start to grow around the age of 5 months.
• Fun fact!  Sharks get a new set of teeth every two weeks, and they will have at least 40 sets of teeth in their lifetime.
• Teeth help people to speak clearly.
• Newborn children are born without teeth.
• Milk teeth are called temporary teeth.
• The second set of teeth is called permeant teeth.
• Incisors are nicknamed “cutting teeth.”
• Canines are nicknamed “tearing teeth.”
• Premolars are nicknamed “grinding teeth.”
• Molars are nicknamed “crushing teeth.”
• A tooth has a crown, root, enamel, dentin, pulp, and blood vessels.
• A tooth is white because of the enamel.
• A tooth’s root is protected by another hard layer called the dentine.  It is not as hard as the enamel but together they make the teeth very strong.
• When tiny food particles get stuck on the teeth and in between the teeth, this is called tooth decay.
• Bad breath is caused by food getting stuck between and in teeth.

What Did You Learn?

•  How many different types of teeth are there?  There are four different types of teeth; the molars, premolars, incisors, and the canines.
• What makes teeth so hard?  Teeth have different layers and the hardest layer is the enamel.  Enamel is the hardest material in the body.  With the enamel and the dentine, teeth are very hard.
• What is the purpose of teeth?  Teeth help the body to be able to chew food so that they can swallow it.
• What system do the teeth help?  The teeth help with the digestion system.  Actually, digestion starts with the teeth.
• How many teeth do adult humans have?  Adult humans have 32 teeth.
• What is the first set of teeth called in a human?  A human has the first set of teeth and these are called Milk Teeth or temporary teeth.
• Which tooth helps with cutting?  The incisors help with cutting food to make it smaller for swallowing.

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