Wisdom teeth are third molars.
The first molars usually grow into the mouth at around six years of age. The second molars grow in at around age 12. The third molars usually will try to grow in at around age 18 to 20 years. Actually, they are no different than any other tooth except that they are the last teeth to erupt, or grow into the mouth. They are just as useful as any other tooth if they grow in properly, have a proper bite relationship, and have healthy gum tissue around them.