Teeth
Have you had a wobbly tooth? The chances are that you have a wobbly tooth at the moment. You have had your wobbly teeth since before you were born but they did not wobble then. They were forming deep in your gums. Let us see how the teeth in your mouth have changed over your life.

When you were born there were no teeth sticking out of your gums. This did not matter as you only had liquid food ? milk. Teeth are needed to deal with solid food. At about the age of six months the first teeth started to appear. They were the first incisors and they grew in the middle of the top and bottom jaw. There were two in the top jaw and two in the bottom jaw. About a month later the second incisors broke through the gums and started to grow. They grew on either side of your first incisors. The total of teeth in your mouth rose to eight.

When you were about one year old four teeth broke through the gums further back in your mouth. These teeth were the first molar teeth. Your total tooth count rose to twelve.
At the age of about eighteen months teeth grew up in the gaps between the incisors and the molars. These four teeth were the canines and the number of teeth in your mouth reached sixteen.

Between the ages of two and three years, four more teeth appeared at the back of your mouth. These were your second molars. The tooth total was now twenty and you had your first set of teeth. This set is known as the milk teeth.

For three years your milk teeth served you well then some of them began to wobble and fall out. The first teeth to go were the first incisors and first molars. They left gaps but soon out of the gums rose the white tops of more teeth. If you are eight now, you may be losing your second incisors and later when you are nine you will get new canines too. At about ten years of age you will start to get some teeth you have not had before. They are called premolars and there are two of them on each side of each jaw. As you get the last of your premolars you will lose the last of your milk teeth ? the?second molars at the back of your mouth. When the new ones have grown you may have to wait for about four years, until you are seventeen, until your last four teeth arrive. They are new too. They are large molars and are called wisdom teeth.

The second set of teeth is called your adult set and there are thirty two teeth. These teeth are not replaced by a third set. They are called permanent teeth. If you take care of them they will last a lifetime. How many of your permanent teeth do you have now? You should have four chisel-shaped ones at the front in your top and bottom jaws. These are your incisors. You may also be getting four new pointy ones next to them. These teeth are your canines. Go and look in a mirror, smile and don't mind the gaps.

Why do children need new teeth?
Once a tooth is fully formed it cannot grow any more. This is unlike a
bone, which keeps on growing and makes you larger. The bones in the jaw grow and make the mouth larger so more foods can be eaten to feed your growing body. The milk teeth are too small for the jaw and too small to deal with the extra food so the body grows a new larger set of teeth. These teeth fill the jaw and can deal with the size of the meals that adults eat.

What makes milk teeth wobble?
When a milk tooth is ready to be lost the body takes back materials from the root. The body recycles these materials and uses them again. As the materials are taken from the root, the root gets shorter and shorter. The purpose of the root is to hold the tooth in the gum. As the root gets shorter it can no longer hold the tooth and the tooth starts to wobble. Eventually the tooth falls out and makes way for the tooth growing below.

Do permanent teeth wobble?
They shouldn't do. The roots of the permanent teeth should hold them firmly in place all your life.

Why are teeth different shapes?
They are different shapes because they have different tasks to do. The incisor teeth are chisel-shaped because they bite into the food and cut it up. The canine teeth are pointed so they can tear. The molars have large bumpy surfaces so they can grind up the food.

Why are the incisor teeth at the front?
The teeth are in their various positions because the positions are the best for their work.
The biting incisor teeth and tearing canine teeth need to be at the front so they can deal with the food first and break it up into lumps which can be taken into the mouth. The molar teeth are further back in the mouth so that they can grind up the lumps into smaller pieces. The muscles, which work the jaws, are at the back of the mouth too and they can help the molars with their work.

Why do we have teeth?
To break up food into small pieces so that it can be swallowed and digested inside the body.

What causes toothache?
The tooth is covered by a hard white coat called enamel. Underneath the enamel is a softer living substance with nerves in it. If the enamel is damaged and cool air or water can reach the living tissue, the nerves send messages to the brain and we sense the pain called toothache.

How can toothache be cured?
By a visit to the dentist. The dentist may drill out the damaged enamel and replace it with a material called a filling. This prevents cold air or water reaching the living substance in the tooth and the toothache goes away.

How can the enamel be damaged?
By poor tooth care. Teeth become covered in a sticky substance called plaque. It contains microbes, which feed on sugar in the food. As they feed they change the sugar into acid. The acid breaks down the enamel and damages it. This can lead to toothache or even the loss of the tooth.

How can teeth be kept healthy?
By regular brushing at least twice a day, once after breakfast and once at night just before you go to bed. The cleaning will remove plaque. You should also cut down on the amounts of sugary foods you eat and the sugary drinks you have. For example, you could change a snack in the following way. Instead of eating a biscuit, which contains a large amount of sugar, have a stick of celery or a piece of raw carrot. These foods do not contain sugar and act like your toothbrush by removing plaque.