Wisdom teeth are the third set of molars that typically erupt into a person’s mouth between the ages of 17 and 21, although they can emerge in a person's mid-twenties. They are called wisdom teeth because of the age the teeth usually emerge, during the so-called “age of wisdom.” When these teeth are healthy and properly positioned, they help a person to chew more effectively.

However, wisdom teeth frequently fail to completely emerge through the gums, or come in sideways, tilted or otherwise positioned incorrectly. This may cause complications that can only be solved by removing the tooth. About 85 percent of wisdom teeth eventually must be removed, according to the American Association of Oral and Maxillofacial Surgeons.

Wisdom teeth erupt at the back of the mouth. By the time a person is about 9 years old, the crown of the wisdom tooth begins to develop in a small sac inside the jawbone. Most people have four of these teeth – also known as third molars – and they usually come in between the ages of 17 and 25 and are fully rooted in the bone of the jaw by a person’s 40s. The likelihood of complications developing is lessened if extraction occurs before the roots become fully imbedded in the jawbone.

Wisdom teeth are the last teeth to erupt, and as a result often cause problems when they finally emerge. In many cases, wisdom teeth come through the gum only partially or not at all (impaction). An impacted wisdom tooth may grow in sideways, emerge only partially from the gum or remain trapped beneath both the gum and the bone.

An impacted wisdom tooth usually must be removed (extracted). A tooth that only partially erupts creates an opening for bacteria to create an infection. Wisdom teeth that emerge in a poorly aligned fashion may damage adjacent teeth. In some cases, a cyst may form near the tooth that can destroy bone or tooth roots.

Many people who need to have wisdom teeth extracted become nervous because of stories they have heard about unpleasant extractions. Patients are urged to talk to their dentist about their concerns. Many dentists provide information about the process and an atmosphere designed to reduce such anxieties. For instance, patients may be allowed to listen to music or watch videos during the procedure. Relaxation techniques such as deep breathing also may help patients relax. Full sedation is also available for patients who prefer to remain asleep during the procedure.