Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2245935.
Edit: 4/15/2017 If you downloaded the sith mask before 4/15/2017 two detail were missing from the mask. The detail on the forehead and around the mouth were missing. See the forth picture for more information. If you did print the mask with the missing details and wanted those parts, I upload those two parts that could be added to your mask. They are labeled "Mouth Detail" and "Forehead Detail."
I decided to add details to my previous Sith Mask. I tried to make it look more like a Sith Acolyte Mask from Star Wars the Old Republic.
Since this is one of my favorite mask I will look to improve it more as my 3d designing skills increase.
From Wiki:
Sith Acolyte was a rank within the Sith Order prior to Darth Bane's reformation. The term was used to refer to Force-sensitive apprentices who had only just started on the dark path under the tutelage of a more experienced Sith Lord to rightfully bear the mantle of Sith.