The average adult has thirty-two teeth by age 18, sixteen on the top and sixteen on the bottom. Wisdom teeth are the last teeth to come in. They usually start to appear in the teen years. When they align properly, and gum tissue is healthy, wisdom teeth do not have to be removed. Wisdom teeth can be impacted, which means they have nowhere to grow. In these cases, they should be removed. This can usually be determined by 16 or 17 years of age. Removal of wisdom teeth in this age group is recommended, because the roots are not fully formed and the bone surrounding the impacted tooth is less rigid, making surgery less traumatic. Because these teeth come in the teen years, or the age of wisdom, they are called “wisdom teeth.”