Schools usually all fill up thier seats at somewhat the same rate. This is becuase upon granting acceptance on Dec first, all have holes to fill thereafter. True, some offer less than 100% of their seats on dec first, but most aim to get the best students asap.
If you are talking about interviews only, you are right on...Case, Nova, OSU, Creighton, VCU, Temple, Marquette, etc. all send out invites sooner rather than later.
You need to keep in mind that this is a business, the sooner a school can fill their spots, the less time they need to pay faculty/staff to conduct these interviews and the sooner the faculty/staff can work on other things. And by accepting the best students a school can find, the school is essentially investing in its financial future. Granted that these great predents morph into great dentists and even better businessmen then trun around and donate to the ol' alma mater. Phew! What a long post full of generalizations. 🙂
IMO, if I were a school, I would begin this process ASAP and try to nab up all the best students early in the process because many predents withdraw themselves from interviews after they have secured a handful. They do this for many reasons: time away from work/school, confidence in at least one acceptance on dec one, expense, and so on.....
In my case, I withdrew from a half dozen schools since I knew I was going to get in somewhere. Though I would have attended any of these schools if I were offered an interview earlier, the fact that they started late killed their chance at getting me. (sounds cocky, but it's true)
anyway, I am done here.....