Wisdom teeth, or third molars, normally begin to erupt between the ages of 17 and 21. Some people may notice them trying to come in after the age of 21, but their late arrival may be because the structure of the mouth has slowed their progression. The size of the mouth and the teeth are different for every individual. Many people have more than enough room for their wisdom teeth to grow in naturally. Others have much less space at the back of their mouth. This can be due to the size of their teeth or the length of their jaw bone. Wisdom teeth are normally larger than the rest of the teeth in the mouth and may grow in at an angle if there is not enough room for them to move freely into place.