Baby Teeth

A child's mouth has 20 initial teeth, also called primary teeth, baby teeth, or deciduous teeth:

• Four second molars

• Four first molars

• Four cuspids (also called canine teeth or eyeteeth)

• Four lateral incisors

• Four central incisors

  
  

For each set of four teeth, two teeth are in the upper arch (one on each side of the mouth) and two are in the lower arch (one on each side of the mouth).

Permanent Teeth

The adult mouth has 32 permanent teeth:

• Four third molars (also called wisdom teeth)

• Four second molars (also called 12-year molars)

• Four first molars (also called 6-year molars)

• Four second bicuspids (also called second premolars)

• Four first bicuspids (also called first premolars)

• Four cuspids (also called canine teeth or eyeteeth)

• Four lateral incisors

• Four central incisors

Teeth Functions

Your teeth are used for:

Biting and tearing. The central incisors and lateral incisors are mostly used for biting and cutting, and canine teeth are primarily used for tearing food.

Grinding and crushing. The premolars, molars, and wisdom teeth are mostly used for chewing and grinding food.

How Teeth Are Structured

Each tooth has three main parts: crown, neck, and root.

• The crown is the visible part of the tooth. A protective layer called enamel covers the crown.

• The neck is the area of the tooth between the crown and the root.

• The root is the portion of the tooth that extends through the gum and into the bone of the jaw.

  
  

The following chart shows when your child's primary teeth (also called baby teeth or deciduous teeth) should erupt and shed. Eruption times vary from child to child.

As seen from the chart, the first teeth begin to break through the gums at about 6 months of age.

Usually, the first two teeth to erupt are the two bottom central incisors (the two bottom front teeth).

Next, the top four front teeth emerge. After that, other teeth slowly begin to fill in, usually in pairs -- one each side of the upper or lower jaw -- until all 20 teeth (10 in the upper jaw and 10 in the lower jaw) have come in by the time the child is 2 ½ to 3 years old.

The complete set of primary teeth is in the mouth from the age of 2 ½ to 3 years of age to 6 to 7 years of age

Other primary teeth eruption facts:

• A general rule of thumb is that for every 6 months of life, approximately 4 teeth will erupt.

• Girls generally precede boys in tooth eruption.

• Lower teeth usually erupt before upper teeth.

• Teeth in both jaws usually erupt in pairs -- one on the right and one on the left.

• Primary teeth are smaller in size and whiter in color than the permanent teeth that will follow.

• By the time a child is 2 to 3 years of age, all primary teeth should have erupted.

Shortly after age 4, the jaw and facial bones of the child begin to grow, creating spaces between the primary teeth. This is a perfectly natural growth process that provides the necessary space for the larger permanent teeth to emerge. Between the ages of 6 and 12, a mixture of both primary teeth and permanent teeth reside in the mouth