(3) 3rd molar teeth Explanation: A wisdom tooth, in humans, is any of the usual four third molars. Wisdom teeth usually appear between the ages of 16 and 25. They are generally thought to be called wisdom teeth because they appear so late - much later than the other teeth, at an age where people are presumably "wiser" than as a child, when the other teeth erupt. The term probably came as a translation of the Latin dens sapientiae.