Animal teeth and their functions

In a nutshell

Humans use teeth to chew and break down the food they eat before it is swallowed. As humans are omnivores, they have different types of teeth to help break down different types of foods.

Types of teeth and their functions

Humans have four types of teeth: incisors, canines, molars and pre-molars.

type	function	Image
Incisors	Found at the front of the mouth, these teeth cut and chew food.
Canines	Found at the front of the mouth, these teeth tear and grip food.
Pre-molars	Found in between canines and molars, these teeth tear, grind and crush food.
Molars	Found at the back of the mouth, these teeth grind and crush food.

Milk and permanent teeth

The number of teeth humans have change as they grow.

Milk teeth

At around five months, babies start to develop milk teeth (baby teeth). Between five months and age five, around $20$ milk teeth develop. These teeth are softer than adult teeth and are more vulnerable to damage.

Permanent teeth

After age five, baby teeth start to fall out and are replaced by $32$ permanent teeth (adult teeth).

Teeth and diet

The mouth is moist and warm and it regularly comes into contact with sugar from food. This makes it a favourable environment for bacteria to grow. Eating lots of foods that are high in sugar can increase the risk and rate of tooth decay.

Tooth decay

Teeth have a hard outer layer called enamel. Sugar in food feeds bacteria in the mouth which grow to form a sticky layer on teeth called plaque. These bacteria produce acid which erodes the enamel and causes damage resulting in tooth decay.

Preventing tooth decay

There are many ways to prevent tooth decay.

Examples

Eat foods low in sugar.
Brush teeth with fluoride toothpaste (fluoride is a substance that strengthens enamel).
Floss in between teeth to remove plaque and bits of food.
Go to the dentist regularly for check-ups.

Teeth in carnivores and herbivores

Animals have different teeth based on their diet.

Carnivores	Carnivores have canine teeth as they kill other animals and need to tear flesh. They also have molars which help them to grind and crush bones.
Herbivores	Herbivores have incisor teeth as they only eat plants and need to tear plants. They also have molars which help them to grind and crush hard stems.
Omnivores	Omnivores have incisors, canines and molars to help them cut, rip and crush both animals and plants.