The back molars are the last of the baby teeth to fall out and are replaced by permanent premolars that fill in the gap from the canine teeth to the permanent molars further back in the mouth. The first permanent molars come in around age 6 and arrive in the back of the mouth behind the primary molars, without any other teeth falling out. The second set of molars follows behind the first at ages 10-12 (aka “12 year molars”) and the third molars (aka “wisdom teeth”) start developing under the gums around ages 14-16 and coming in around ages 16-18. Therefore, the second molars come in between 11 and 13 years.