Wisdom teeth, or third molars, usually appear between the ages of 17 and 25. While it varies from person to person, when these teeth appear, they frequently cause problems. Most people have a small jaw, which can cause wisdom teeth to become impacted and unable to break through the gums. Some people's wisdom teeth only partially penetrate their gums, resulting in a flap in their mouth that traps germs. This can result in infections and other problems. Infections, damage to other teeth, and even cysts can result from an impacted teach. Another issue with wisdom teeth is that they are so far back that they can be difficult to clean. This also raises the risk.