I'm often asked "what is the difference between a dentist with a D.M.D. degree, and one with a D.D.S. degree?"  Actually, very little, except the dental school from which they graduated.

My Alma Mater, The University of Pennsylvania awards a D.M.D. degree to emphasize their focus on oral medicine, rather than oral surgery.  However, I think that every dental school recognizes and teaches the connection between oral and systemic health.