The last teeth to develop and erupt into the jaws are called the third molars. Third molars usually erupt in the late teen years, which coincides with passage into adulthood and is referred to by some as the age of "wisdom teeth".

Wisdom teeth used to serve a useful purpose, but are now considered vestigial organs. A vestige is a degenerative or imperfectly formed organ or structure which no longer performs a useful function. Wisdom teeth have become "outdated" for many reasons. Our ancestors’ diet was made up of far coarser food than our own and a lack of hygiene meant that impurities such as dirt and sand were consumed regularly. This caused teeth to abrade significantly which meant they took up less space in the jaw. Permanent teeth were also frequently lost at an early age, which would create more space in the jaw. Due to the coarseness of the food it was harder to chew and the jaw itself would develop into a larger bone as it was working much harder. All of these factors would create more space for the wisdom teeth when they came in.

Wisdom teeth serve no useful function and will often cause damage because when a wisdom tooth becomes partially exposed through the gums it cannot be cleaned properly and can collect food debris, bacteria and plaque around itself. This can result in tooth decay, gum disease, infection and abscess of not only the wisdom teeth, but of the nearby molars and surrounding gum tissue. The molars in front of the wisdom teeth are sometimes lost because of cavities and gum disease caused by the inability to clean the wisdom teeth properly. Cyst formation and other destructive pathology are also seen around impacted wisdom teeth. There may be pain and swelling, or you may have no symptoms at all, even though the other teeth in your mouth may be at risk of damage.

If removal of the wisdom teeth is necessary, the procedure is recommended in the late teenage years, before the roots are completely formed. Surgical procedures in general are better tolerated when one is young and healthy, and the gum tissues tend to heal better and more predictably when young. Most people experience minimal disruption of their normal routines, and time off from work or school is usually minimal. At this point it is worth noting that the removal of wisdom teeth can be of great benefit to your ultimate oral and general health.