Human teeth are crucial when it comes to chewing food. Teeth are made of bone and begin to appear in humans around 6 months of age. Babies are born with no teeth and when they first start to appear they tear through the gums and the process can be quite painful.
Humans first grow what's called primary teeth, and there are 20 of them, 10 on the top (maxilla) and 10 on the bottom (mandible). These teeth will fall out, one by one, as they are pushed and replaced by permanent teeth. There will be a total of 32 permanent teeth, 16 on the maxilla and 16 on the mandible.
To name the (permanent) teeth we can divide the mouth into 4 parts: top left, top right, bottom left, bottom right. We can do this because these 4 parts are identical. On each part, starting from the back, we have, 1 wisdom, 3 molars, 2 premolars, 1 canine, and 2 incisors. Total of 32 teeth. In some people wisdom teeth will also show up making the total 36.
Incisors are sharp and are used for cutting when you first bite down on food. Canines are also sharp, are pointy and are used for tearing food. Molars are very strong, they are wide, they have ridges, and are used for grinding food before it is swallowed.
The outer most layer of the tooth is the enamel. It is the hardest part of the body. This is the part that must be cleaned regularly to prevent cavities. The second layer is the dentine and provides support to the enamel. The third layer is the cementum which covers the root. The fourth layer is the pulp, which makes up the centre and is living tissue. The pulp is where blood vessel and nerve endings are found.
- Plaque: a film that develops over the teeth that is comprised of bacteria. If it is not removed it can lead to cavities and/or gingivitis. If allowed, plaque will mineralize and become tartar.
- Cavity (caries): Also known as tooth decay, it is a disease which damages the tooth structure. It can lead to pain, tooth loss, infection, and sometimes death from a severe infection. Cavities are caused by bacteria, which are not cleaned regularly, which produce acid. This acid damages the enamel. These bacteria feed primarily on the various sugars we eat.
- Discoloration: This is primarily an aesthetic problem and can be caused by tea, coffee, tobacco, bacteria, etc. There are many products on the market now that claim to make teeth whiter, but many of them can damage the enamel and make the tooth more susceptible to cavities.
- Other problems that can arise can include larger than normal teeth, poor spacing, teeth not being straight. Many times braces and retainers are recommended to correct these problems.
- Wisdom teeth: these are 4 teeth that grow in the back of the mouth. Sometimes there is not enough room for these teeth and they need removal. If they are not removed then they end up squeezing the other teeth which can cause crowding.