Is there a way to determine how old a person is?

Question

I'm thinking about the Chinese Olympic gymnasts who have been question and thought to be under 16 and therefore should not have been allowed to compete. Are their any genetic tests or physical tests that can be done to prove it one way or another?

Answer 1

Cut them in half and count the rings..oh wait was that trees.. no i'm pretty positive it works for humans too  

Answer 2

Who ever heard of an adolescent lying about his age?  ;-)

The doctors must have cut through a bone and counted the rings !

... or perhaps they thought it would be simpler to check the gymnast's ID card !