I agree with Sharp... The red shading on the teeth looks odd. other than that though I really like the originality. Keep up the great work.

The shading on the teeth looks off to me, but I like the concept!

You shouldn't be shading the back of the teeth red. Maybe pink, but why red? Look up a ref for the shape of the teeth too.

I love it!  

@Tpoe: have you ever looked at a white ceiling?  Do you see white or do you see the purples, yellows and greens in there too? 

I don't really like the amount of colors, it looks like there's too much to me.