When you smile, you may show those white/ivory/yellowish things that we call teeth. Being a dentist, they are something that I spend a lot of time looking at and something I consider to be important. They are there for biting, for chewing and for smiling. I’m sure you’ve seen your teeth before but take another look.
We are all different and lots of people vary from the following general statements. It would be boring if we were all the same.
Humans will generally have 32 permanent teeth. That’s including wisdom teeth. Lots of people won’t have wisdom teeth so have less teeth than this. Some people will have 28 teeth. I have 30 teeth; I’ve got my top ones but not my bottom ones. I’ve got no idea why. And it’s not just wisdom teeth that you could be missing. Anyone can be missing any tooth. There is more on development in the parent’s section.
You have different types of teeth and they have different uses. The incisors are at the very front of your mouth. They are teeth made for slicing and cutting. So they are used to bite off a chunk of food that can then be chewed up. Most people have 8 permanent incisors; 4 on the top, 4 on the bottom.
Then you have your canine teeth. These teeth are for gripping on to the backside of a gazelle as it tries to escape away from you on the Savana. Lions are more effective at using these teeth. Humans; less so. We don’t use our canines to their full potential but I’m certainly not saying you should try taking down a gazelle with your teeth. Leave it to the professionals.
At the back of your mouth you have molar teeth. These are large teeth made for mushing up that gazelle once you’ve caught it and sliced off a chunk with your incisors. You will start with either 8 or 12 of these teeth, depending on your wisdom tooth situation.
Then you have premolar teeth. Most people have 8 of these. These are positioned between your canine teeth and molar teeth. Premolar teeth are essentially teeth that haven’t decided what they want to be when they grow up. Do they want to be the big, strong, workhorse teeth for chewing or do they want to be the nice, shiny, show-off teeth at the front which claim all the glory in a lovely smile? In the end, they didn’t decide and do a bit of both.
So what are your teeth made of? Despite the differences in shape and function, all of your teeth have roughly the same make up. The bit of tooth that shows above the gum is the crown of your tooth. The bit below your gum is called the root. On the outside of the crown of your tooth, the tooth will have a shell made of enamel. This acts as a hard, protective layer to keep out bugs and keep the tooth happy. Inside the enamel shell, the tooth is made of dentine. This is what the bulk of the tooth is made of. It’s much softer than the enamel. The whole root of your tooth is made of dentine.
At the centre of the tooth, there is a nerve. When the tooth is young, the nerve lives in a little box (or chamber) in the crown of the tooth and in a canal that runs down the root of the tooth, out of the bottom of the tooth and off to your brain. The nerve contains the stuff that built your tooth in the first place. With time, the nerve of the tooth gets bored and carries on building more dentine, filling in the nerve chamber and canal as it seems to retreat out of the tooth. So in older teeth, the nerve is much smaller.
Around the tooth is what supports and holds your teeth in place. Again, this is the same for all healthy teeth. There is bone that surrounds the root of the tooth. Between the tooth and the bone is a tiny ligament. This is a springy layer that helps you to control forces when you’re chewing. Overlying the bone and up to the neck of the tooth is a covering of gum. The gum forms a sleeve around the neck of the tooth. This sleeve is there to keep out food, bugs and anything that you wouldn’t want wedged in around your teeth such as chewed off fingernails.
Very simply, a tooth is made of dentine with a shell of enamel on the outside of the crown (the bit that shows above the gum). There is a nerve in the middle which tells your brain how your tooth is feeling day to day.
Now you know about your teeth, you need to know how to look after them.