i believe fangs are determined by morph data.
it is not a separate mesh. it uses the same mesh as regular human teeh, they just stretch the vertices of the canines according to the morph data.
same goes for elf ears (they are just regular human ears with stretched vertices
Yes, and as of Dawnguard, vampires will no longer have fangs, which likely means that the CK will no longer support morph data for the teeth. I don't think it will be possible to add fangs to the races that don't have them or to add the fangs back once Dawnguard does away with them, but it definitely doesn't hurt to see if there is a way to do add fangs anyway, even if it's through an unconventional way.
Also, the CK is refusing to launch right now. 
There, it finally loaded.
How are the fangs determined by morph data, anyway? It looks like it's probably determined by an unspecified FaceGeom file, and is very likely hardcoded into the different races from the looks of it.
The fangs are attached to the keyword "vampire," which will likely no longer hold true for Dawnguard. Now I am going to try and see if it's possible to find out how the fangs are attached through the keyword. It looks like hardcoding of some form, though.