It looks like your Face normals are inverted. This is why you cannot see the head in the render. This happens to me at times when creating characters.

Try selecting the faces that don't appear in the render and go into Normals-Reverse

You can also check what direction your normals are facing by going into Display-Polygons-face Normals

I hope this helps. I'm also new to this site so apologies if im incorrect or am too late in the reply.