Download the model in the .wings file format here Also, check out the tutorial to see how it was made here

There's a few n-gons in the final mesh that might be an issue tho, especially in deformation areas like the cheeks. I've not worked a lot with n-gons, but I think they're best avoided if possible, at least in deformation areas.

Poles, and tris can both lead to problems, and in my experience you're almost always stuck with a pole in the cheek like you have now, but I think the n-gon can be avoided with a quick change.

I'd make the these [see attached image] changes to it. Preferably the middle suggestion, tho both do work out two n-gons in favor of quads, and it could be a matter of trying both and seeing which looks better.

I can't download your mesh, for w/e reason I'm not clever enough to work the download site I guess. So I grabbed one of the images from your tutorial. I hope you don't mind the paint-over, I'm just trying to offer some hopefully usefull feedback.

Cheers.

*EDIT - Found the trick, you need to have cookies turned on.

Thanks for the comments. I like your method for fixing the cheek n-gons, Warlock, just did exactly what you said. (didn't feel i needed to re-upload the mesh though)