Someone else will probably post a better suggestion.. If I'm right, you want to actually shape the head itself to be more oblong, not just the face?  I see two options:

1. Use magnets to reshape the head a bit, and make a head morph out of it (You can then use this headmorph in a program like MorCloth and apply it to hairs and such too. There are plenty of magnet tutorials around.

2. Export the head part into a 3rd party modeller and scale it. It seems daunting, but is actually really easy to do if you get a hang of it. Especially in a newbe friendly one like Wings (which I've used to make custom morphs) Then you apply the scaled head as a morph, just like you would have if you'd used magnets.. The advantage of this if you get the hang of it, is that you can really customize the shape, beyond just scaling.