If you use Darker Nights, or Interiors Enhanced, or any other mod that makes things quite dark, you may have noticed that NPCs and the player's mouths stay glowing red.  This is really distracting.  I poked around a couple times and the fix wasn't obvious, but now that I know a bit more about how things work I was able to solve this finally.

There is an extra mesh that gets attached to the mouth for shadowing/simulated subsurface, with an effect material that renders a color gradient that retains its emission color regardless of the light.  So, I just cut that gradient alpha way down.  The insides of mouths are a tiny bit darker overall, but it looks more real IMO and you don't have the glow-in-the-dark mouth.

I put this under bug fixes because it seems like the best place to go.

Enjoy!

MOD AUTHORS -- IF YOU HAVE A MOUTH MOD AND WOULD LIKE TO INCLUDE THIS, BE MY GUEST, just give me credit please!