Like Father Like Son
Most of dental problems have a little thing to do with genetic. Tooth crooking is an exception.
David's father has a mild form of cross bite involving only one tooth (Fig.1,2: L (lateral incisor)). Usually our upper teeth are in the front of our bottom teeth. In cross bite, one or more top teeth can be behind the bottom ones.
When David is 7 years old, four of his top front teeth are behind bottom ones (Fig.3,4: LCCL; C: central incisor). David has more severe form of cross bite. It appears that his upper jaw is under development. So he needs early braces to bring the upper jaw forward.
Xin Wei, DDS, PhD, MS 1st edition 03/06/2012, last revision 03/08/2012