I was in this position last year. Some schools didn't decide to tell me anything until April or even May. I'd get ready to re-apply just in case. If any of the schools offer exit interviews with the dean I'd jump all over that opportunity. They'll tell you why you weren't accepted/interviewed and that can give you a lot of help for polishing up your application. After my exit interviews last year I changed a lot about my app and now I have 3 acceptances!
This is what I did:
1. Applied earlier
2. Applied more broadly
3. Overhauled personal statement per suggestions of adcoms
4. Emphasized some ECs differently (amazingly some schools will ignore ECs if they aren't categorized how they expect them to be, nice huh?)
5. Got more clinical experience
Now I suppose SDN could have told me all of that too but it was very reassuring to hear straight from the adcoms what they thought was lacking in my app.