Dental School Opinions?

Alright, I would like to go to dental school in the future and plan to stay in the Pittsburgh, Cleveland, Buffalo vicinity, or Ann Arbor. I know of Case Western, UPenn, Pitt, and Michigan having good dental schools, so which one, in your opinion, would be the best for specialization in orthodontics?
Also, I have heard that going to the same school for undergraduate and graduate school is not a good idea. I am mostly concerned because because my two front runners for undergrad school would be michigan and pitt. Any feelings on that?