Judy Freitag, Age 10, Of Sarasota, Fla., for her question:
How do teeth begin to grow? '
A baby cuts his very first tooth when he or she is six to nine months old. It is an incisor or cutting tooth in the front of the mouth, and the eruption often causes the baby a lot of trouble. This, however, is long after the tooth began to grow deep in the jawbone.
Your teeth grow from seeds or buds, somewhat like pumpkin plants grow from crisp coated seeds buried in the ground. These tooth buds began to form inside your baby jaws almost six months before you were ready to leave your mother's body and be born into the world. No teeth appeared until you were about half a year old, but all this time the seed buds in your jawbones were preparing your teeth. At the age of two and a half you should have 20 pearly milk teeth a row of 10 in your top jaw and a row of 10 in your bottom ,jaw.
Teeth are tougher than the hard bones and the strong nails on the fingers and toes. The body builds them from the calcium we get from milk and from scraps of chemicals we eat with health giving salads and vegetables. If we fail to eat the right foods our tooth buds cannot grow good, strong teeth for us.
The crown of a tooth is the round pearly hump that pokes above the gums. Each tooth bud starts its work by building the crown of white enamel, harder than hard. When the crown is all finished, the bud begins to build the roots that reach down like tough fingers into the jawbone. Meantime the crown is pushed up higher and higher above the jaw, and when the roots are about two thirds grown it breaks through the tender pink skin of the gum.
The 20 milk teeth are meant to last only a few years. The permanent teeth begin to form deep in the ,jaws while these baby milk teeth are still growing. The material in the roots of the baby teeth may be taken and reused to build the second teeth which are meant to last for the rest of your lifetime. When time comes for the baby teeth to go, they often fall away with no trouble at all because their roots are no longer there to hold them in the jawbones.
When you are about 12, you should have 14 permanent teeth in your upper jaw and 14 in your lower jaw. Between the ages of 17 and 21 your tooth buds should produce four more grinders called wisdom teeth. But sometimes these wisdom teeth in the back of the jaws fail to break through the gums.
Our tooth buds can produce only two sets of teeth, and if we 10se one of our precious permanent teeth it cannot be regrown. Its coating of glossy enamel is the hardest substance in the body, but if damaged it cannot mend or repair itself. A tooth cannot cure or heal a cavity. For this reason sensible people keep their pearly teeth well brushed and twice each year they trot bravely along and let the dentist check to see that all is well.