You could but i woudl take time to select each one and manipulate them, depending on how crooked they were you could cut the sides off, use the clone brush to fill in bits of teeth - or replace the whole section of teeth from another photo
If you google fix teeth Photoshop a whole bunch of stuff will come up - thsi tutorial is followable in DIP
http://www.lunacore.com/photoshop/tu...s/tut018_4.htm and you can modify teh ideas to suit.
Otherwise shoot me the photo and I might be able to come up with some advice