Well, let's put this in its proper perspective... I'm from the deepest, darkest heart of Appalachia, and in fact both sides of my family settled there in the late 18th century (just after the Revolutionary War). But 90% of the people there are not as impoverished or ill-educated as many believe. Most of the folks from my neck of the woods are thoroughly middle class with nice homes (and yes, running water and in-door plumbing---my grandparents bought their first television in the early 1960s so that they could keep up with NASA and the Mercury space program) and hold down decent jobs in the professions and journeyman trades. The men in my family are all coal miners, but I went to a good high school and then left home in the early 1990s, went to college, and now work as a white collar professional in the work force. Everyone else in my community had the exact same opportunity as me to achieve higher education, and some did, but many did not, choosing to remain home close to their roots. Its been that way since before World War II, but unfortunately, the "Beverly Hillbillies" and Lyndon Johnson's "War on Poverty" has projected the myth that the entire region still lives in the 19th century. This is not true. However, small pockets of individuals living in the "hollers" do live up to those stereotypes, but it's largely by their own choice, not because modern American society has somehow by-passed them during the country's march to modernity. I just want to get this into the discussion before some well meaing folks paint the entire region with a broad brush.
Concerning the availability of dental services, it's always been there, but like in the rest of the country, its high cost and the lack of dental insurance preclude many folks from getting proper treatement. It's no different in Appalachia than it is, say, in East L.A. or Harlem.