But the tissue depth markers are not the whole picture.

Building a face from a skull requires more than hitting target depths at discrete points.

It requires integrating knowledge of how muscles, particularly the muscles of facial expression and mastication, attach to the bone and what shape they produce under the skin.

It requires making decisions about soft tissue features — the nose, the ears, the lips, the eyelids — that are not directly determined by the underlying bone structure.

The nose is a particular challenge.