Be careful here. What you mainly want is to remove yellowing--do this by moderate desaturation first. Then lighten only a small amount. There should be more desaturation than lightening. You might have to work some teeth individually. I usually select the teeth and work them on a separate layer, then adjust Opacity.
The same thing is true of eyes. First desaturate yellow and red--maybe 'touch out some veins, then lighten only slightly. The most important thing about eyes is to remember that eyeballs are balls. And remember that a healthy eyeball is actually light gray or very light beige, not white.
The curvature of the ball causes cause the edges and into the corners to be slightly shadowed. As well, the upper lid casts a narrow shadow over the ball. It's a very common mistake to lighten out the shadows that create the rounded shape of the eyeballs.
When working on eyes and teeth, evaluate the results at a smallish magnification. If you've gone overboard, it will show up when you pull back from the image.