I've read information about how to shrink doll heads. Some pages I've found:
To be honest, I don't want to do anything this drastic to my dolls. I don't want to mess with the doll's makeup as much as possible because I don't want to repaint! I've read that their heads get really hard as rock after shrinking too and I don't want that either!
The shape of their heads do not really bother me. I mean, I know Ever After High dolls have round faces, but I'd rather keep my Madeline Hatter's face as it is because when altered, it would resemble a Princess Malucia doll. Not that it's a bad thing, but I bought Maddie because it is an Ever After High doll. I bought it for what it is.
Shrinking doll heads and reshaping them is cool if you want your dolls to look as proportionate as possible, but I've realised that these are fashion dolls. The big doll head is a statement and shows off the makeup and hair styling much better. It's just my opinion though. If you want to try this method on your dolls, go ahead. Just be careful because there's lots of acetone involved.