Is my son developing too early???

I have asked many times this question but nobody seems to want to answer
me!!!
My son is 16 months old and has 8 teeth and has 4 mollers coming
through...
the 2 on top are almost completely down and the bottom ones are giving him
a
bit more trouble...His sleeping is all out of contole and I would just
like
to know if this is unusall for a child to get these so early!!!