Creating a facial depiction—a representation—from a skull is an anatomically-informed process with applications in the forensic and archaeological arenas. Practitioners may work in two dimensions (2D) or three dimensions (3D), using manual, computer-generated, or fully automated methods (using algorithmic and statistical shape modelling), with a wide range of presentation options. In forensic scenarios, such depictions can contribute to an investigation into unknown human remains when other scientific methods such as DNA profiling, fingerprints, or dental analysis are unavailable. An image might prompt recognition by someone who knew the individual in life, providing investigative leads. In archaeological contexts, depictions of historical individuals enable the distant past to come into contemporary focus through a recognition of common humanity.
There is robust scientific support for the methods employed to recreate the facial shape of the Goucher and Cohen mummies. 3D skull models for each were created from CT data and imported into a virtual sculpture system (Geomagic Freeform) that allows the artist to assess features of the skull by touch-feedback and to construct the major facial muscles accordingly. This process is guided by pegs placed at specific facial landmarks (shown in purple) indicating average soft-tissue depths for the relevant population group. As no soft-tissue data is available for ancient Egyptians, we use minimum-mean data from a modern study to account for diet and lifestyle changes between ancient and modern people. Recognized anatomical standards are then used to predict the appearance of individual features, such as the particularities of the eyes, nose, and mouth in relation to overall head and face shape.
The Cohen mummy presented an additional challenge in that her mandible (lower jaw) is missing. In order to suggest her living appearance, a mandible was estimated using an orthodontic method based on relative proportions of the upper face, yet it remains an educated guess. (Estimated structures are shown in blue.)
After extensive discussions between the co-investigators, it was decided to depict the Goucher and Cohen mummies in grayscale, with facial textures digitally applied from existing photographic sources to denote sex and age guided by the anthropological analysis, within the limits of what can be stated with confidence about the appearance of these ancient women. However, the application of facial textures should be carefully considered as this may influence how depictions are interpreted. For this reason, we tend to avoid introducing color into forensic depictions to mitigate misidentification, but some historical individuals may be presented in color if there are reliable archaeological records and scientific analysis associated with the remains. Facial texturing such as skin tone, hair, wrinkles, and other details like moles or superficial scars cannot be determined from skull analysis alone. Yet, without these details, faces are less relatable. Therefore, we avoid including textures that make too strong a statement about individual appearance and utilize techniques such as blurring and varying opacity to place focus on facial shape, which can be confidently predicted.