A delicately sculpted face on the interior, revealed when the bust underwent a computed tomography (CT) scan, indicates that Nefertiti may not have been the flawless beauty depicted on the bust's exterior.
Compared to the outer stucco face, the hidden limestone visage had less depth in the corners of the eyelids, laugh lines around the corners of the mouth and cheeks, less prominently regal cheekbones and a tiny bump on the ridge of the nose.
"We acquired a lot of information on how the bust was manufactured more than 3,300 years ago by the royal sculptor," said the chief author of the study published Tuesday in the April issue of Radiology, Alexander Huppertz.
Huppertz, who is director of the Imaging Science Institute at Berlin's Charite teaching hospital, said that advances in CT technology allowed the team to do a deeper analysis of the bust.
The 3-D surface reformation of the inner limestone sculpture indicated that it was created in several steps, and the artist's makeover may have reflected the aesthetic ideals of the era.
The study said that the CT scan, which is most commonly used in screening patients for disease, could reveal vulnerable areas of the fragile bust to help protect it in its handling.
"Non-invasive CT technology and very advanced 3-D post-processing tools allow us greater insight into the internal composition and conservation status of the sculpture," Huppertz said.
"This knowledge will greatly contribute to the preservation of this priceless antiquity."
Nefertiti, renowned as one of history's great beauties, was the wife of Pharaoh Akhenaton, remembered for having converted his kingdom to monotheism with the worship of one sun god, Aton.
German archaeologist Ludwig Borchardt brought the figure to Berlin in 1913, a year after it was unearthed on the banks of the Nile.
It is a prime attraction at the city's Altes Museum but will move into its own hall at the newly renovated Neues Museum when it reopens to the public in October.
The bust has long been a source of friction between Egypt and Germany. Cairo alleges that Borchardt fraudulently spirited it out of the country and has demanded its return.
German authorities have reportedly said they are willing to consider whether the statue could be returned to Cairo temporarily for display and the study's findings could help determine whether it could safely make the trip.