The wisdom teeth grow at the back of your gums and are the last teeth to come through. Most people have four wisdom teeth – one in each corner.
Wisdom teeth usually grow through the gums during the late teens or early twenties. By this time, the other 28 adult teeth are usually in place, so there isn't always enough room in the mouth for the wisdom teeth to grow properly.
Because of the lack of space, the wisdom teeth can sometimes emerge at an angle or get stuck and only partially emerge. Wisdom teeth that grow through like this are known as impacted.