The tooth’s structure
How many teeth do you have in your mouth, and how many more will you get? What does the tooth look like under the gums?
A tooth is made up of a crown, which is the upper part of the tooth and a root that is the lower part. The tooth is attached to the gum and jaw bone. A tooth has three different layers:
- The enamel. Coats the outside of the tooth. It is the body’s hardest tissue.
- Dentine. Makes up most of the tooth.
- The pulp. Contains blood vessels and nerves from the roots. The roots are lined with cementum. This moulds around the teeth in fibres and holds the tooth in place in the jaw.
A human has 20 milk teeth that fall out when you are a child, and 28 adult teeth or up to 32 teeth if all your wisdom teeth develop.
Milk teeth start to develop in week 14 of pregnancy. The crown forms first. Children’s first teeth become visible when they are between six and eight months old, however their roots are not fully formed until a child is 1-1.5 years old.
Children grow 20 milk teeth that start to fall in the late primary school years. When the milk teeth loosen and the adult teeth erupt, the roots of the milk teeth absorb into the dentine.
The first permanent crowns start to form shortly before childbirth. The process continues until a child is between six and seven years old. The roots of the adult teeth are fully formed approximately three years after the teeth have erupted. The foundations of the adult teeth are in the jawbone. They erupt when a child starts to lose their milk teeth.
