I am always puzzled how hrt can seem to round off the head to a more feminine shape from most of the pics i have seen.

Even if the hair is finer and regrowing at the temples and with a rounder face, the skull shape shouldn't change and i thought the shape when the hair is grown longer should be the same like a guy's; thick at the top, flat at the 10 & 2 o clock positions, and thick at the sides.

Is fat also added under the scalp to give a rounder look or some other effects? Hope some of the sisters here can give your personally experience on this.

Subcutaneous fat can indeed help out.

Some CIS women have the same problem. Certain hair styles work and others make the issue worse. A hairdresser will tell you that side swept cuts like bobs and avoiding angular bangs etc will help round out a squarer face.