I used this to

1. Teeth

2. Are you
less than 14
years old? If
so, chances
are you have
had at least
one loose
tooth.

3. Having loose teeth when you are young is normal.
In fact, after spending the first three years of your life
getting a set of teeth, you then spend the next ten
years slowly losing them one by one.

4. 1. How many years
does it take to grow
your first set of
teeth?
a) 3 years
b) 4 years
c) 6 years
d) 7 years

5. Do you
have a loose
tooth, or have
you lost one
lately? If
so, this topic
will interest
you.

6. Teeth
aren’t organs
like our heart
or brain –
they aren’t
there and
ready to work
as soon as we
are born.

7. 2. Which one is different?
– Heart
– Lung
– Brain
– Tooth

8. Although as
babies we have the
beginnings of our
first teeth, they
aren’t visible until
we are about six or
seven months old.
Once the teeth
begin to
appear, most
children get all of
them by the time
they are three years
old.

9. These are called primary
teeth, and there are twenty
of them in all. These teeth are
also known as baby teeth. As
we get older, one by
one, these teeth begin to
loosen and eventually fall
out. The first primary tooth
usually falls out when a child
about five or six years old.

11. 3. How many
baby teeth
should a
person
have?
– 16
– 20
– 28
– 24

12. Primary
teeth fall out
because they
are pushed out
by the
secondary
teeth, which
are beneath
them in the
gums.

13. 4. What makes the baby teeth fall out?
– They get old and decay.
– They have no root and fall out.
– They are pushed out by the adult teeth.
– They must be pulled.
5. In the above question, who is they?
– Baby teeth
– Adult teeth
– Your Tongue
– The Class

14. Secondary teeth are also called
permanent teeth. Slowly, the
permanent teeth grow in and push
the baby teeth out, and by age
fourteen most children have all their
permanent teeth. There are twenty-
eight teeth in a permanent set. That
is eight more than in the first set of
primary teeth.

15. By age twenty, four more permanent teeth will
have grown in at the back of the mouth. These last
four are called wisdom teeth. They don’t make us
smarter, though. In fact, they sometimes cause
problems and have to be extracted by a dentist.

16. 6. Draw and Label

17. The part of
the tooth that
you can see
above the gums
is called the
crown.

18. The crown of
each tooth is
covered with a
very hard, shiny
material called
enamel. Enamel
is the hardest
substance in your
whole body. It is
the tooth’s
shield, protecting
it from being
cracked by hard
things you eat.

19. 7. What part of the tooth can you see and what
is it made?
– You see the Tierra and it is made of bone.
– You see the Root and it is made of Hairs.
– You see the Head and it is made of bone.
– You see the Crown and it is made of Enamel.

20. The next
layer of a
tooth is called
dentin. It
makes up the
largest part of
the tooth and
is similar to
bone.

21. The pulp contains the tooth’s nerves and
blood vessels. The nerves inside the pulp
allow us to feel pain by sending pain messages
to the brain.

22. The root is covered by
cementum, which is a kind
of glue. This cementum
connects the root of each
tooth to the
jawbone, keeping each
tooth in place.

23. 8. Draw and Label the Parts

24. 9. Why do primary teeth fall out?
–The root breaks off the jawbone.
–They are pushed out by the permanent
teeth.
–The enamel begins to crack.
–The cementum begins to dissolve.

25. 10. What does the word enamel mean in this
passage?
– The layer of the tooth next to the root.
– The part of the tooth that sends messages to the
brain.
– The part of the tooth that connects to the
jawbone.
– The very hard shiny coating on a tooth.

26. 11. Why do you think it is important to take
care of your secondary teeth?
– Secondary teeth are the last teeth a person gets.
– Secondary teeth will fall out in about seven years.
– Secondary teeth have nerves that connect them
to the brain.
– To make sure there is room for the wisdom teeth.