How many teeth does he have? All together should be 20 -10 top and bottom. There should be 4 incisors 2 canines and 2 molars. The first permanent molar erupts behind the last baby molar around 6 years old, usually around the same time as the front bottom incisors start to wobble. It can happen younger (or older) but I've never seen one come though in a 3 year old. Incidentally teething symptoms for permanent teeth are generally mild compared to baby teeth.