Molars

Molars are a type of tooth in humans and other mammals, located at the back of the jaw. Their primary function is to break down and grind food before swallowing. The English term "molar" derives from a Latin word meaning stone-grinder.

Molars differ from front teeth (incisors) in form: their upper surface is broad with ridges and small grooves. This broad surface enables food to be crushed when the lower and upper jaws come together.

Structure

A tooth consists of a crown (the part visible in the mouth) and roots (the part embedded in the jaw bone). The crown surface is covered by enamel, the hardest substance in the body. Below it lies dentine, and at its core is the pulp cavity containing blood vessels and nerves. Molars typically have two to three roots; those in the upper jaw usually have more roots than those in the lower jaw.

Number and eruption

Primary teeth (baby teeth) do not include true molars counted among permanent teeth; instead, smaller teeth occupy those positions and are later replaced. A fully developed adult has 32 teeth, of which 12 are molars—three on each side of each jaw. The third molar at the back is known as the wisdom tooth and typically erupts in late adolescence.

Health

The grooves on the molar surface readily trap food and bacteria, making molars the most common site where tooth decay begins. Oral hygiene—regular brushing and reducing sugar intake—lowers the risk. When decay reaches the pulp, pain and infection can occur, requiring dental treatment.