this is the mask of Enji Koma also known as the Devil Ape in the Anime Tokyo Ghoul.
soldier and paint
Use a soldering iron at the temperature of your plastics melting point to weld the two pieces together.
paint the teeth white and wait for it to dry then cover the teeth up and paint the everything thing red.
blender
I used a reference image from the anime and modeled everything of of that in blender.
