Caspar de Vries
Sep 14, 2016
We know that 3D printing can be used to shape the future. However, it may surprise you to know that it can uncover the past too. The University of Melbourne has achieved just this; harnessing the power of 3D printing to recreate the face of a 2,000-year-old Egyptian mummy.
No one knows how the skull of Meritamun, a young woman from ancient Egypt, ended up at the University of Melbourne. Lying forgotten in the archives for years, its origins were mysterious. Dr. Ryan Jefferies, the curator who discovered her, was concerned that the remains could be decaying slowly from the inside – but without technology, there would be no way of telling.
Mapping the skull
CT-scans provided experts at the university with clear images of the skull within – which was still in excellent condition. The results showed that Meritamun, which means ‘beloved of the god Amun’, had been in her mid-twenties when she’d died. She had tooth abscesses, which could have resulted from eating sugar or honey. Bone marrow swelling suggested that the woman had also suffered from anaemia, which was common in those days and was often caused by malaria parasites.
Completing the face
Wonderful though the images were, they didn’t provide the complete picture. The research team wanted to discover what the woman had looked like when she was alive, so they set about using 3D printing technology to find that out.
After they’d gathered a full range of CT images, they used a 3D printer to create a replica of the embalmed skull inside the bandages. Using this as a base, specialist sculptor Jennifer Mann began to reconstruct Meritamun’s face.
The 3D printing workflow
When the head was scanned the CT files contained more than just the bone information that was used in the end. Soft tissue, cartilage and bandages were also included in the file. In order to extract just the bone information, the researchers needed to select the appropriate density range from the scans. The generated 3D file still contained some of these other materials, and they were removed in Blender. The skull model was split in half to ensure an optimal print quality. Fairly standard Cura settings were applied to execute the print. A standard nozzle (0.4 mm) was used with no particularly high resolution settings, as they would exceed the CT scan's resolution and increase the already extensive printing time of 140 hours. Most of the adjustments that were made in Cura concerned the support material that was used for the entire skull and its eye sockets in particular. Finally, the size of the skull was assessed against the initial CT scans and historic data of ancient Egyptian skull sizes.
After the skull had been printed, the face was reconstructed. The technique used for this was highly sophisticated and involved the placement of plastic fiduciary markers to suggest where tissue might be thicker or thinner on the face, based on population data averages. The team then had to make an educated guess on the nose shape, based on the size of the skull’s nasal cavity. Finally, hair, pigmentation and make-up was applied to provide a detailed impression of what the young Egyptian woman might have looked like.
The past retrieved
Without CT scans and 3D printing, researchers would need to remove the bandages from her face to see what is underneath - which would damage the mummy and desecrate her remains. With these technologies at hand, the skull of a woman who lived at least two millennia ago could be replicated without removing these bandages.
Mann points out that all reconstructions are approximations, and cannot be taken as precise representations. However, her work on Texan murder victims’ skulls proved to be highly accurate - which suggests that the reconstructed face of Meritamun may be too.
When commenting to the university’s newspaper, imaging technologist Gavan Mitchell said:
It has been a hugely rewarding process to be able to transform the skull from CT data on a screen into a tangible thing that can be handled and examined.
Janet Davey, the forensic Egyptologist who worked with the team to discover more about Meritamun, adds: “By reconstructing her, we are giving back some of her identity.”
The retrieval of her face only marks the beginning of getting to know how Meritamun lived. According to Dr. Varsha Pilbrow, a biological anthropologist at the University's Department of Anatomy and Neuroscience, students can learn how populations can be affected by their environments through Meritamun's case. More can be read about the unraveling of Meritamun's past on the University of Melbourne's website.
3D printing not only allows you to get creative, but can be used in scientific and historic endeavours too. Ready to discover more? There's a lot to explore!
Hero image by Paul Burston, University of Melbourne.