Teeth are one of the most important structures in the human body. They are essential for chewing and biting food, which is the first step in digestion. Teeth also help to form words when we speak.
There are two main types of teeth: incisors and molars. Incisors are the eight teeth at the front of the mouth, used for biting off pieces of food. Molars are larger teeth at the back of the mouth, used for grinding food into smaller pieces before swallowing.
The adult human mouth has 32 teeth. However, baby teeth (also known as primary or deciduous teeth) start to fall out from around 6 years old, and by about 12-13 years old, all 32 adult teeth should have come through.
Most people have four wisdom teeth (two on top and two on bottom), which usually come through during late adolescence or early adulthood (between 17-25 years old). Wisdom teeth can sometimes cause problems as they may not have enough space to grow properly and can become impacted (stuck). Impacted wisdom teeth may need to be removed by a dentist or oral surgeon.
Teeth are made up of three main parts: enamel, dentin and pulp.
Enamel is the hard outer layer that you can see when you look in your mouth; it is white in colour. Dentin is a yellowish layer under enamel that makes up most of each tooth; it is harder than bone but not as hard as enamel. Pulp is the innermost layer of each tooth; it contains blood vessels and nerves that keep each tooth alive and healthy.
Tooth decay occurs when acids produced by plaque (a sticky film of bacteria that constantly forms on our teeth) break down enamel; this process starts at sites where there is already damage to enamel from cavities or cracks. Once decay reaches dentin, it spreads more quickly because dentin is softer than enamel. If Decay progresses all the way through to pulp, it can cause an infection or abscess (a buildup of pus); this requires root canal treatment to save the tooth from being extracted/removed entirely