Saqqara, Egypt ? The arrest of tomb robbers led archaeologists to the graves of three royal dentists, protected by a curse and hidden in the desert sands for thousands of years in the shadow of Egypt’s most ancient pyramid, officials announced Sunday.

The thieves launched their own dig one summer night two months ago but were apprehended, Zahi Hawass, chief of Egypt’s Supreme Council of Antiquities, told reporters.

That led archaeologists to the three tombs, one of which included an inscription warning that anyone who violated the sanctity of the grave would be eaten by a crocodile and a snake, Hawass said.

A towering, painted profile of the chief dentist stares down at passers-by from the wall opposite the inscription.

The tombs date back more than 4,000 years to the 5th Dynasty and were meant to honor a chief dentist and two others who treated the pharaohs and their families, Hawass said.

The tombs did not contain mummies.

Their location near the Step Pyramid of King Djoser – believed to be Egypt’s oldest pyramid – indicate the respect accorded dentists by Egypt’s ancient kings, who “cared about the treatment of their teeth,” Hawass said.

Hieroglyphic details including eye and tusk symbols representing the dentistry profession are seen at right on the entrance to 4,200-year-old tombs honoring a chief dentist, pictured on the wall at left, and two other dentists who served the nobility of the 5th Dynasty. The tombs are at the Saqarra pyramid complex south of Cairo, Egypt.

During a visit to the site, Hawass pointed out two hieroglyphs – an eye over a tusk – which appear frequently among the neat rows of symbols decorating the tombs. He said those hieroglyphs identify the men as dentists.

The pictorial letters also spell out the names of the chief dentist – Iy Mry – and the other two – Kem Msw and Sekhem Ka. Hawass said the men were not related but must have been partners or colleagues to have been buried together.

Although archaeologists have been exploring Egypt’s ruins intensively for more than 150 years, Hawass believes only 30 percent of what lies hidden beneath the sands has been uncovered. Excavation continues at Saqqara, he said, and his team expects to find more tombs in the area.

Saqqara, about 12 miles south of Cairo, is one of Egypt’s most popular tourist sites and hosts a collection of temples, tombs and funerary complexes.