Wisdom teeth are very much like your other permanent teeth. The main difference is that they are the last to develop and grow in (when you're "older and wiser"). Most people have four wisdom teeth, one in each corner of the mouth. Some people naturally lack one or more of their wisdom teeth.
Wisdom Teeth and Your Dental Anatomy
There are several types of teeth. Each type is designed either for biting or for chewing. The wisdom teeth are molars, or chewing teeth. Both the upper and lower jaws have three molars on each side. The wisdom teeth are the last in line, which is why they're called "third molars." Because there are eight other molars to do the chewing, most people can get along fine without wisdom teeth.
Anatomy of a Tooth
The crown is the part of the tooth that has a hard chewing surface. Below the gumline, the root anchors the tooth to the bone. Nerves and blood vessels enter and exit the tooth through the roots.