How old are they when their baby teeth faal out?

Ben has lost his two top teeth, he is just over 4 months old - is this normal?

Scooby's started falling out at that age and it also depends whether he is playing tug of war on tug ropes. But as far as i can tell he has all of his adult teeth and he is now 6months old.

Lisa & Scooby
*doggiehug*