Craftster user gorgaus, as an art installation, put on a fashion show in which the women participating wore enormous plastic sleepy-eye doll heads.
They are made from fibreglass. They are quite light, they have a stem at the back of the neck that leads down to the waist where there is a back brace so all the weight is on their hips. The wigs are heavier than the heads, especially the geisha style one. They used dancers instead of models cause they thought they might have more strength and balance.
More pictures at the link. And in the comment thread, gorgaus provides detailed technical descriptions.
Link via Matthew Caverhill