Its all nice & smooth...I just don't like the teeth. you shouldnt use black lines to outline each one: instead, imply the outline. Leave the black on the top and bottom where it 'starts' to show the vertical line between the teeth. Leave the beginning, but remove the line itself. Remove the horizontal lines as well: leave the single dots of black...one dark pixel in the corners of teeth where 4 meet, but make everything else white.
edit: Scratch that
it didn't work as well as drawing on paper.
i quick checked it out to see how it would be
edit again: but it does work out if you do that + a fade to black towards the back molars