Tooth Development Guide

Primary Teeth Permanent Teeth

Incisors are the first of four distinct types of teeth you have. These are the most visible and are located in the center and front of your mouth. There are eight of them, four in the upper jaw and four in the lower jaw. Each incisor has one root and the primary purpose is to shear or cut food.
Canines are the next most visible teeth, and they are located at the corners of the mouth. These teeth are sometimes called cuspids. Each person has four canines, two in each jaw. Like the incisors, canines have only one root, but it is a heavy root, and the tooth has a pointed crown.
Premolars are sometimes called bicuspids and are the second type of teeth to appear in your mouth. They are located just back of the canines, and there are eight of them; four in the upper jaw and four in the lower jaw. These teeth may have one or two roots. They have as their primary purpose, the crushing and tearing of food.
Molars are the last teeth to appear in your mouth, and they are located in the back section. You have twelve permanent molars, six in each jaw. In the upper jaw, the molars usually have three roots, in the lower jaw you find two roots. Your molars are used to grind food.

Primary Teeth (Baby Teeth)

When a baby is born, the teeth, though not visible, are present under the gums. At the age of three months, the gums begin to harden and then become red and swollen. This means that soon (about the age of six months) the first teeth will appear. The pre-school child has a set of 20 teeth, and by the time the child is 2½ years old, all have erupted. These teeth are known as the primary or deciduous teeth.

Approximate Eruption Dates of Primary Teeth

Tooth:	Age at Eruption:	Shed at:
4 Central Incisors	5th to 9th month	6 to 7 years
4 Lateral Incisor	7th to 10th month	7 to 8 years
4 First Molars	12th to 14th month	9 to 11 years
4 Canines	16th to 20th month	10 to 12 years
4 Second Molars	20th to 28th month	9 to 11 years

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Permanent Teeth

Approximate Time of Eruption of Permanent Teeth

Tooth:	Age at Eruption:
4 First Molars	5½ to 6 years
4 Central Incisors	6 to 7 years
4 Lateral Incisors	7 to 8 years
4 First Premolars	10 to 11 years
4 Second Premolars	11 to 12 years
4 Canines	10 to 12 years
4 Second Molars	12 to 13 years
4 Third Molars (wisdom teeth)	16 to 21 years

About the time a child is six years old other teeth have formed in the back of the jaws behind the primary teeth. The first to appear are called the six year molars, and these are the first "permanent" teeth you get. There are four six year molars, two in each jaw. Since these teeth do not replace any primary teeth, they are sometimes mistaken for deciduous molars. The six year molars are extremely important teeth and must be well cared for since the shape of the mouth depends to a large degree upon these molars.

After the first molars come in, the first of the primary teeth become loose and either fall out or are pulled out very easily. From now on, the temporary teeth begin to be lost and the teeth that take their place are permanent. Eventually, there will be 32 of them.

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