It was with a force greater than an atom bomb that Mount Vesuvius erupted and blotted out Pompeii in 79 A.D.

Or, not blotted out, exactly.

The city’s destruction, and the thing that has kept Pompeii so fascinating over the centuries, entails a paradox: The surge of ash and hot gas that blanketed thousands of victims also, simultaneously, preserved their bodies—along with their colorful art, sparkling jewelry, wine jugs, scrolls, and other cultural remnants.

Now, scientists are using new imaging technologies to examine in detail the bones and teeth of those killed in the blast.

Detailed casts of Pompeii’s victims—made by pouring plaster into the small cavities in their ash-encapsulated remains—have long prevented sophisticated scanning of this nature. The 19th-century plaster is so dense that today’s standard imaging technology can’t distinguish between the thick outer cast and skeletal pieces inside. But researchers recently used a multi-layer CT scan to obtain imagery never before possible, then used software to make digital 3-D reconstructions of skeletons and dental arches.

The initial images reveal two major surprises.

For one thing, these ancient people had “perfect teeth,” according to Agenzia Giornalistica Italia, a discovery that scientists linked to a healthy diet and high levels of fluorine in the air and water near the volcano.

ANSA

The scans also support a theory that many of those who were killed after the eruption died from head injuries—caused by falling rock or collapsing infrastructure—and not from suffocation.