Hippo ivory and gold-plated false teeth lost by a man about 200 years ago look set to be snapped up at an auction.
They were uncovered by detectorist Peter Cross, 59, who was scouring land in Waterstock, Oxfordshire.
The false teeth are thought to date to between 1800 and 1850, and would have been very expensive at the time.
An expert said they were similar to a pair worn by the first US president, George Washington.
Mr Cross, who lives in Brill, near Bicester, said: "A dentist friend said the owner would have paid between £200 to £300 in the 1800s, and that would have bought half the houses in Brill back then - a very affluent village.
"I've shown the teeth to many people and consulted the British Dental Association and the British Museum. Everyone's amazed - and everyone wants to take a photo of them. They're unique."
Mark Becher, who leads Hansons Auctioneers' historica department, said: "Until Peter had shown me those, I had never seen a set before in my life - they're very unusual.
"From what I've seen they're very similar to teeth worn by George Washington, so they're very interesting."
Stephen Shipperley, Mr Cross's lifelong friend, now owns the land and allowed him to search on it.
He said: "For centuries Waterstock was an estate owned by the landed aristocracy.
"My best guess is one of their landed gentry friends were riding across the land and their teeth fell out."
They will be sold on 25 November at Hansons Auctioneers in Derbyshire.