I just got a car with a dented frame up front from a front end collision, obviously. The bumper appears to be pushed in a little so that the bumper cover is no longer flush with the hood, which overhangs by about 1 cm. My question is if anyone has been successful with unbending frame damage like this or not?

 

Without seeing any pics of the damage, it sounds like you have a bent rad support wich could easily be pushed out. Especially if it is only 1cm. You could probobly just pop the hood and pull it out by hand lol.

 

Just because the bumper dose not line up dosent mean the frame is bent...like Disease said, it can be your rad support, or bumper support if it has one.

 

Try to get some pics up so we can see what is going on.