George Washington's False Teeth
It'd be embarrassing enough to misplace your own dentures, so imagine how red-faced you'd be if you couldn't find a historic pair that belonged to the first U.S. president. But that's exactly what happened in 1981, when the Smithsonian Institution's National Museum of American History discovered that one pair of Washington's chompers, which had been loaned to the Smithsonian in 1965 by the University of Maryland Dental School, had vanished from a locked storage room where they'd been kept. A search of the facility failed to produce any sign of the teeth [source: UPI].
The following year a museum employee revealed that Washington's lower plate had turned up, in an area of the museum accessible only to Smithsonian employees, but the top half was still missing. Though popular myth portrays Washington as wearing wooden teeth, his dentures actually contained ivory and gold, and there's a possibility that the thief destroyed the relic in order to melt down the gold and sell it [source: Molotsky].