The teeth are the hardest substances in the human body. Teeth play an important role in speech besides being essential for chewing. A normal adult mouth has 32 teeth.
Parts of the teeth
A tooth is basically made up of two parts
- The crown is what you see when you smile or open your mouth. It’s the part that sits above your gumline.
- The root is below the gumline. It makes up about 2/3rd s of the tooth’s total length.
When considering cross section, there are five parts of a teeth.
Enamel: The hardest, white outer part of the tooth. Enamel is mostly made of calcium phosphate.
Dentin: A layer underlying the enamel. Dentin is made of living cells.
Pulp: The softer, living inner structure of teeth. Blood vessels and nerves run through the pulp of the teeth.
Cementum: A layer of connective tissue that binds the roots of the teeth firmly to the gums and jawbone.
Periodontal ligament: Tissue that helps hold the teeth tightly against the jaw.
Babies start growing their first teeth before they are born, but we can’t see them until they are about 6 to 12 months old.
Humans grow two sets of teeth during their lives.
- The first set has 20 teeth baby teeth. When a child is about 6 years old, these teeth become loose and fall out.
- Over the next few years 28 permanent teeth replace the baby teeth. When a person is around 20, four more back teeth, called wisdom teeth grow in.
The four front teeth are called incisors. They are very sharp and are used for cutting and chopping food. You use your incisors, for example, to crunch the skin of an apple.
Types of Teeth?
We have different types of teeth in our mouth. Each one has a different function or specific job.
- Incisors : The sharp, chisel-shaped front teeth Incisors are used for cutting food. There are four upper, four lower (8 Total) Incisors.
- Canines (Cuspids) : Canines are shaped like points (cusps) and are used for tearing food. There are 4 total Canines.
- Premolars : Premolars have two pointed cusps on their biting surface and are sometimes referred to as bicuspids. The premolars are for crushing and tearing. There are 8 Premolars.
- Molars : Molars used for grinding, these teeth have several cusps on the biting surface. There are 8 Molars.
- Wisdom teeth or third molars: These teeth erupt at around age 18, but are often surgically removed to prevent displacement of other teeth. There are 4 wisdom Teeth.
Each dental arch is divided into a right and a left quadrant:
- Quadrant 1 (upper right)
- Quadrant 2 (upper left)
- Quadrant 3 (lower left)
- Quadrant 4 (lower right)
Each quadrant consists of a central incisor, a lateral incisor, a canine (cuspid), 2 premolars and 3 molars.
