I'm not going to delete what I wrote above or edit it, but after re-reading what you seem to want to do, I doubt my suggestion will help.
You're using Poser to Pose and animate him talking, planning on using the scene export form S-M or Kurv to get it into LW, aren't you? So that's why you need all the morphs to work in Poser, so it all follows through in the export.
I suppose you could do the above, but you'd still have to build your own teeth morphs, and you'd have a second figure to have to export. I don't know how either of those plugins work, so I can't help there, and I can't get the smith micro scene export thing to work to try it out on something.

Personally I think you'd be better off just  assembling your new mesh in Lightwave and using the  BGtoMorph plugin to add the MTs you want to your new figure and animating it entirely in Lightwave. (9.6, not 5.5). ;-)

But yeah, that's really time consuming, and probably not want you want to do. Can't you just make new morph targets for the "bad" teeth to make them closer to what you want?