Chapter X: Dangers From Poor Teeth

We have learned that chewing is not merely a process of cutting our food into such lumps as we can swallow without hurting ourselves; but that the food must be ground up fine and thoroughly mixed with the saliva, that the saliva may reach every particle of starch. If we do not have good teeth, we cannot grind our food as fine as it ought to be ground, and, as a result, a great deal of the starch will not be reached by the saliva.

Nature starts every child with a full set of good, strong, clean teeth. These teeth, which we call first, or milk, teeth, are not very large, but they are perfect in every respect and last until the second, or permanent, teeth come in. That is, they will last so long _if they are taken care of_. If they are not taken care of, they will decay just as the later teeth will decay, and they must be cared for in the same way.

[Sidenote: Why we have baby or milk teeth]

Boys and girls sometimes wonder why they have a set of teeth that come out before they can have the teeth that must last them the rest of their lives. This is simply because there is not room enough in a child's mouth for the big, permanent teeth. We must have teeth while our jaws are growing, so we have first a set of little teeth. Then just as soon as our jaws get large enough for the big teeth, the little teeth come out and the big ones come in.

Teeth are about the hardest substance in the body. If we take care of our second teeth, they should last as long as we live. The only reason they do not last is because we do not take care of them. If a person would keep his teeth clean all the time, he would rarely be obliged to have a single permanent tooth pulled.

[Sidenote: Why teeth break easily]

Teeth are so hard that they are brittle, that is, they break easily. Glass is brittle, and you can chip off a piece of glass with a pin by sticking the pin into a crack in the glass. In just the same way you can chip off a piece of a tooth by sticking a pin between two teeth. That is what often happens when people pick their teeth with pins, or with any other hard substance. A metal toothpick is just as bad as a pin.

Another way by which little pieces are chipped off the teeth is by biting hard things. Sometimes we see boys and girls cracking nuts with their teeth; again we see them trying to bite wires in two. They put their teeth to many uses for which teeth were never made. They do not realize, while they are abusing their teeth in this way, that they are probably chipping the enamel, which is the hard, shiny covering of the tooth, and are destroying the one protection that their teeth have against decay.

[Sidenote: Why teeth decay]

When a little piece is chipped off a tooth, an opening is made through the enamel. Through this opening germs may lodge in the inner part of the tooth, which is soft. When this happens, a little black speck appears on the tooth, and after a while the tooth begins to ache. If you have a toothache, you go to a dentist, and he probably finds that germs have caused the tooth to decay until there is a hole extending into the very center of it.

Teeth grow very close together, but there is always a little space between them. Whenever you eat anything, particles of the food get into these spaces and if allowed to remain there, soon decompose. These decomposing particles of food between the teeth will gradually soften even the enamel, and in this way little openings are made for germs to get into the teeth.

[Sidenote: How to care for the teeth]

Never pick the teeth. You cannot make them clean by picking them. Every morning and night brush your teeth with a stiff toothbrush and a little tooth powder. Brush them both crosswise and up and down, to get out everything from between them. Do not think you have done your duty if you brush only your front teeth, the ones that show. Brush the back teeth just as thoroughly as you do the front teeth. Very few people will see your back teeth, but these decay just as fast as your front teeth, if they are not kept clean.

[Sidenote: How often one should go to the dentist]

Twice each year you should have a dentist examine your teeth, to see if there are any little spots where decay has started. If you have kept your teeth perfectly clean all the time, and have not chipped off little pieces, there will be none of these decayed spots. But it is a safe plan to have the teeth looked over at least twice a year, for you may have broken a tooth without knowing it, and by the time a decayed spot is large enough to cause pain, or has made a hole that you can feel with your tongue, it has advanced much farther than it should have been permitted to do.

=Questions.= 1. Why should you chew your food thoroughly? 2.
Why is it necessary to have baby teeth? 3. How are teeth easily
broken? 4. Why do teeth decay? 5. What must you avoid in order to
protect your teeth? 6. How should your teeth be brushed? 7. Why
should you have your teeth examined twice each year by a dentist?

=Remember.= 1. Take care of your teeth and they will last you as
long as you live. 2. Do not pick them with pins, or toothpicks
of any kind. 3. Do not use them for nutcrackers or wire-cutters.
4. Do not use them for tack pullers. 5. Keep them clean at all
times. 6. Brush them up and down as well as crosswise.