WHAT ARE THE PARTS OF TEETH?
Almost every animal on Earth seems to have small, hard and white structures in their mouths called teeth. We can divide teeth into 2 parts – the crown and the root. The crown is the part of the tooth that we can see. The root is the part which is planted into the jawbone. Teeth have 3 layers: the enamel, dentine and pulp. The enamel is the hard, protective outer layer covering the crown. The dentine covers the nerves of the tooth. The pulp is the soft middle of the tooth containing the blood vessels and nerves.
WHY DO ANIMALS HAVE TEETH?
The main function of teeth is to help animals chew their food regardless of their diet. In general, meat-eating animals (carnivores) use their teeth to rip through flesh and bone. On the other hand, plant-eating animals (herbivores) use their teeth to grind tough vegetation. This means the shape and size of an animal’s teeth varies depending on the food they eat. As humans eat both animals and plants, we have a combination of different types of teeth.
WHAT ARE THE TYPES OF HUMAN TEETH?
The shape of human teeth can be broadly divided into 4 types: incisors, canines, premolars and molars. The incisors are 8 small chisel-shaped teeth (4 on each row) in the front of your mouth that bite into food. Sat next to the incisors are the 4 sharp and pointy canines that tear into food. Your 8 flat premolars (4 on each row) then sit next to your canines and help grind food into smaller pieces. Finally, the 12 molars at the back of the mouth are the biggest and strongest teeth that grind food.
WHEN DO TEETH GROW IN?
Humans have 2 sets of teeth in their lifetime: an initial ‘baby’ set (also called deciduous teeth) and an adult set. The baby set consists of only 20 teeth which usually start to grow about 6 months after birth. They are then gradually replaced by the second set of 28 adult teeth by the age of 13. Then, from the age of 17, the final 4 molar teeth (called wisdom teeth) begin to grow at the back of the mouth. Once fully formed, this second set of 32 teeth can last until the end of your life!
WHY DO WE NEED TO CLEAN OUR TEETH?
However, if we do not clean our teeth properly, our teeth may rot or decay. This is because sugars on our teeth allow bacteria to grow in our mouth. The bacteria then produce acids which destroy the enamel. This can damage the structure of teeth and lead to cavities. This has become a major problem in parts of Africa. For example, it has been estimated over 50% of adults in sub-Saharan Africa may suffer from tooth decay. In order to prevent this, we should brush twice a day with fluoride toothpaste and floss regularly to remove the sugars and prevent bacterial growth.