Medicine??

I posted a similar Q before but basically I want to do medicine but I've been told by a lots of teachers that my grades aren't good enough. I went to a grammar school and I got 4 A* 6 A 2B and in the main subjects:
English language- A* English lit A
Biology/Chemistry/physics (triple award)- I got A for each of them
Maths- B (this is a let down)

I go to the same grammar sixth form and for AS levels I'm doing 6 including maths,bio,chem,psychology, english lit and general studies. I'm doing maths out of school and self-studying and am working really hard on it. For A2 I'm carrying on bio,chem,psychology.

'IF' I get AAAAAA for AS and A*A*A* for my A-levels plus work experience and volunteering, will they look past my bad gcse grades (considering I went to a grammar school). I know I can do better as I didn't bother much with GCSE's and I wasn't as motivated but now that I'm trying harder for AS, is there a possibility of getting into any uni course for medicine?

Im choosing between medicine and dentistry at the moment but most likely medicine