I really do not think it matters (for getting into an OMS residency) where you go to dental school…at least not much. There are advantages and disadvantages of all of them. Both of those schools are excellent, as is UNC Chapel Hill. Go where your gut tells you.
Not knowing anything about either of those two schools, I can tell you that Ohio historically has had a strong Anesthesia background. If you go to Florida, you would perhaps have an opportunity to do some work or externship-type work at the OMS program in Jacksonville, which is excellent.
I have to disagree about preferring a school that is pass/fail. A friend of mine used to be the Program Director at a major OMS program, and he was reluctant to invite for an interview candidates from pass/fail schools, because they could not determine how well those candidates would do with the thinking part. Indeed, I think this is probably why the CBSE started?