The weird whiteness of back teeth
in The Commons
I have been struggling for some time attempting to get open-mouth poses (for singing animation) that don't look like all the teeth are emissive, or have a dentist's light shining on them. It's a weird but pervasive phenomenon I see in promos all the time.
It's almost as though the cheeks and mouth don't cast shadows, and the light goes straight through them, making the back teeth practically glow eerily (and non-humanly).
Does anybody have any explanation for why this happens—and better still, a solution? Man, if somebody made a "Humanized Teeth" product, my wallet would open up by itself.

Comments
I don't know about Iray, but if you are working in 3DL you need to turn shadows on the lights. They are off my default.
Thanks, @JOdel. No, I only work in Iray. I think the last time I did anything in 3Delight was sometime before the flood.
I searched the shop on "teeth" and found something that may be my salvation—or my undoing.