I built it using a 3d skull from Turbo Squid that was a scan of a real skull, but unfortunately the mesh was a set of incomprehensible triangles.
The model skull overlaying it is all quads.
I haven't added teeth yet, so that you can use the latest MH teeth.

You can download the model from: http://www.geekopolis.ca/blender/skull1_249b.blend
And here is the video:
http://www.youtube.com/watch?v=7QV1rlrb-CU