Teeth
Most adults have 32 teeth, called permanent or secondary teeth:
- 8 incisors, 4 canines, 8 premolars, 12 molars, including 4 wisdom teeth
Children have just 20 teeth, called primary, temporary, or milk teeth. They include the same 10 teeth in the upper and lower jaw:
- 4 incisors, 2 canines, 4 molars
Primary teeth start to erupt through the gums when a baby is about 6 months old. The lower incisors are usually the first primary teeth to come in. Most children have all 20 of their primary teeth by age 3.
Children tend to lose their primary teeth between the ages of 6 and 12. They’re then replaced by permanent teeth. Molars are usually the first permanent teeth to come in. Most people have all of their permanent teeth in place by age 21.
Incisors
Incisors are shaped like small chisels. They have sharp edges that help you bite into food. Whenever you sink your teeth into something, such as an apple, you use your incisor teeth.
Canine
Canines have a sharp, pointy surface for tearing food.
Premolar
Premolars are bigger than canines and incisors. They have a flat surface with ridges for crushing and grinding food into smaller pieces to make it easier to swallow.
Molar
The large surface area of your molars helps them grind up food. When you eat, your tongue pushes food to the back of your mouth. Then, your molars break up the food into pieces small enough for you to swallow.