I believe you need some lightsphere in MH for teeth. Done, with my recent upload "Normal_teeth lightsphere". I use it with different skin and it 's work ! Take me some hours to find the right way, work on my PC with it's gamma, maybe you can adjust it with the 'AdditiveShading' for your own.
It's just Normal_teeth not for Star_teeth with white feature.
You can add it in Windows >MH folder (inside Programm File (x86)) >Data >lightsphere. You can save that in your MH >document >V1 >Data >Teeth.
You can add the .mhmat and .thumb in the same way but in Teeth folder.
All the description are found in the Assets Contribution >Material : http://www.makehumancommunity.org/conte ... phere.html