You bite into an apple and then try to start talking to your
friend about yesterday's math homework. Suddenly something
feels funny - one of your baby teeth has fallen out! It's been
loose forever, and now there it is, right in your hand. And you
have an empty space in your mouth big enough to poke a drinking
Before you put that tooth under your pillow, did you know that
there is much more to that tooth than meets the eye? A single tooth
has many different parts that make it work. And teeth play an
important role in your daily life. They not only let you eat stuff
like apples, they also help you talk. So let's talk teeth!
, your teeth weren't ready to work from the day you were born.
Although babies have the beginnings of their first teeth even
before they are born, teeth don't become visible until babies
are about 6 to 12 months old.
After that first tooth breaks through, more and more teeth begin
to appear. Most kids have their first set of teeth by the time they
are 3 years old. These are called the
or baby teeth, and there are 20 in all. When a child gets to age 5
or 6, these teeth start falling out, one by one.
A primary tooth falls out because it is being pushed out of the
way by the permanent tooth that is behind it. Slowly, the
grow in and take the place of the primary teeth. By about age 12 or
13, most kids have lost all of their baby teeth and have a full set
of permanent teeth.
There are 28 permanent teeth in all - eight more than the
original set of baby teeth. Between the ages of 17 and 21, four
more teeth called
usually grow in at the back of the mouth. They complete the adult
set of 32 teeth.
Let's take a tour of your teeth. Look in the mirror at your
own teeth or check out a friend's smile. The part of the tooth
you can see, which is not covered by the gum (your gums are the
pink, fleshy part), is called the
. The crown of each tooth is covered with
-ul), which is very hard and often shiny. Enamel is a very tough
substance and it acts as a tooth's personal bodyguard. Enamel
works as a barrier, protecting the inside parts of the tooth.
If you were able to peel away the enamel, you would find
-tin). Dentin makes up the largest part of the tooth. Although it
is not as tough as enamel, it is also very hard.
Dentin protects the innermost part of the tooth, called the
. The pulp is where each tooth's nerve endings and blood supply
are found. When you eat very hot soup, bite into a super-cold scoop
of ice cream, fall and hurt a tooth, or get a cavity, it's your
pulp that hurts. The nerve endings inside the pulp send messages to
the brain about what's going on ("That ice cream is
too cold!"). The pulp also contains the tooth's blood
vessels, which feed the tooth and keep it alive and healthy.
The pulp goes all the way down into the
of the tooth, which is under the gum.
-tum) makes up the root of the tooth, which is anchored to the
You've probably noticed that you have different types of
permanent teeth in your mouth. Each one has its own function.
Your two front teeth and the teeth on either side of them are
-zurs). There are four on the top and four on bottom.
Incisors are shaped like tiny chisels, with flat ends that are
somewhat sharp. These teeth are used for cutting and chopping food.
Think back to that apple you ate: You used your incisors to crunch
into the skin of the apple.
The pointy teeth beside your incisors are called
-nine) teeth. There are four of them, two on top and two on bottom.
Because these teeth are pointy and also sharp, they help tear
Next to your canine teeth are your
-lurs), which are also called bicuspid teeth. You have eight
premolars in all, four on top and four on the bottom. You'll
need to open a bit wider to see these teeth, but when you do,
you'll notice that their shape is completely different
from both incisors and canines. Premolars are bigger, stronger, and
have ridges, which make them perfect for crushing and grinding
If you open your mouth really wide, you'll see your
-lurs). You have eight of these, four on the top and four on the
bottom. Sometimes these are called your 6-year molars and your
12-year molars because that is around the time when they come
Molars are the toughest of the bunch. They are even wider and
stronger than premolars, and they have more ridges. Molars work
closely with your
to help you swallow food. How? The tongue sweeps chewed-up food to
the back of your mouth, where the molars grind it until it's
mashed up and ready to be swallowed.
As we mentioned earlier, the last teeth a person gets are wisdom
teeth. These are also called third molars. They are all the way in
the back of the mouth, one in each corner.
Wisdom teeth aren't used for anything and they are often
removed because they can cause problems in a person's mouth.
Some people believe that wisdom teeth may have been used by people
millions of years ago to help them chew food. It's believed
that they're called wisdom teeth because they come in later in
life, when a young person is older and wiser.
Your teeth are great for chewing, but you also need them to
talk. Different teeth work with your tongue and lips to help you
form sounds. Try saying the word "tooth" slowly and
notice how your tongue first hits the inside of your incisors to
produce the hard "t" sound and then goes in between your
upper and lower teeth to make the "th" sound.
And if you love to sing "la la la la la," you can
thank those teeth every time you sing a song. Pay attention to what
happens to your teeth and tongue every time you make the
Treating Teeth Kindly
Brushing your teeth with fluoride toothpaste is your best bet
when it comes to keeping your teeth in tip-top shape. Try to brush
after eating or at least twice a day. It's especially important
to brush before bedtime.
The best way to brush your teeth is in little circles - go
around and around until you have covered every surface of every
tooth. Brush up and down, rather than side to side. You'll also
want to clean between your teeth with dental floss (a special
string for cleaning your teeth) at least once a day. That removes
food and plaque (sticky stuff that can cause cavities or gum
disease) that get stuck in between your teeth. You can also brush
your tongue to help keep your breath fresh!
It's also important to visit your favorite tooth experts -
your dentist and dental hygienist. During your appointment,
they'll look out for any problems and clean and polish your
teeth. Sometimes the dentist will take X-rays to get a better
picture of what is going on in your mouth. You also might get a
fluoride treatment while you're there.
In between dentist visits, you can prevent problems by eating
fewer sugary snacks and sugary drinks, such as soda. Sugar can hurt
your teeth and cause tooth decay, or
. But if you take care of your teeth now, you'll be chewing
like a champ for the rest of your life!
Kenneth H. Hirsch, DDS, and Larissa Hirsch, MD
Date reviewed: May 2007
Originally reviewed by:
Lisa A. Goss, RDH, BS, and Garrett B. Lyons, Sr., DDS
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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