| Your Teeth |
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 straw through.
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!
Tiny Teeth
Unlike
your heart or brain, 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 primary 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 permanent teeth 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 25, four more teeth called wisdom
teeth usually grow in at the back of the mouth. They complete the adult
set of 32 teeth.
Tooth Tour
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 crown. The crown of each tooth is covered with enamel (say:
ih-NAM-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 dentin (say: DEN-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 pulp.
The pulp is where each tooth's nerve endings and blood supply are
found. When you eat 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 root of the tooth, which is under the gum. Cementum (say: sih-MEN-tum) makes up the root of the tooth, which is anchored to the jawbone.
Tooth Types
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 incisors (say: in-SY-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 canine (say:
KAY-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 food.
Next to your canine teeth are your premolars (say:
PREE-mo-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 food.
If you open your mouth really wide, you'll see your molars (say:
MO-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 in.
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
tongue 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 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 becoming older and wiser.
Tooth Talk
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 "l" sound.
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 cavities. But if you take care of your teeth now,
you'll be chewing like a champ for the rest of your life!
Reviewed by: Kenneth H. Hirsch, DDS
Article Source : http://kidshealth.org/
Related Video :
How to Brush Your Teeth Properly - For Kids
No comments:
Post a Comment