How long does it take for wisdom teeth to grow in?

Quite a while: The wisdom tooth (or third molar) starts forming in the mandible behind the second molar at about age 12. The tooth slowly forms the crown and roots over many years. If there is room, the tooth will start to erupt into the mouth around age 18. The tooth can partially erupt, completely erupt, or not erupt at all into the mouth. The dentist will have to determine what treatment each case requires.

Age 20-22: If your wisdom teeth have not erupted by age 22 then they are probably impacted. Have your dentist x- ray and evaluate. Impacted wisdom teeth can cause serious problems and should be removed!

Takes some time: Wisdom teeth may never grow in (fully erupt) and stay impacted. They do not always need to be removed if they are not symptomatic and cause problems.