Actually, the U. of Kentucky had a DMD/MD pilot program about 7-8 years ago which was a 5 year program out of college. They took only a handful of students to complete what was basically 4 years of dental school plus the 3rd year of med school (which is really all that you miss out on in dental school). My understanding was that it was a complete flop and nobody was interested...and why would they be? It's way overkill no matter which side (MD or DDS) you decide to specialize in. I don't think it helped OMFS people much because you could'nt fit into the 6-year track and if you did a 4-year pathway, you still had to do another year of general surgery to be licensed as an MD.
This is all just hearsay from buddies at U of K years ago, I didn't go there.