Dentures sold at auction are one of several specially made to preserve PM's famous diction during rousing wartime speeches

A set of false teeth belonging to Winston Churchill's has been sold for £15,200 at an auction in Norfolk.

The upper dentures, one of several sets made for the wartime prime minister, were specially constructed to preserve his natural lisp and were so important he carried two pairs with him at all times.

The teeth, sold by the son of the dental technician who made them, had been expected to fetch a maximum of £5,000, but they were bought for more than three times that by a British collector of Churchill memorabilia.

The set of dentures were designed to be loose-fitting so that Churchill could preserve the diction famous from his radio broadcasts during the second world war, an expert said.

"From childhood, Churchill had a very distinctive natural lisp; he had trouble with his S's," said Jane Hughes, head of learning at the Hunterian Museum at the Royal College of Surgeons in London. "These are the teeth that saved the world."

The medical museum displays a duplicate set of Churchill's dentures in a glass cabinet alongside other famous teeth including dentures worn by Queen Caroline, the estranged wife of King George IV.

"Churchill wanted to maintain [the lisp] because he was already so well known for it," she said. "The dentures wouldn't quite connect with the top of the mouth, but that was on purpose."

The dentures were made by the dental technician Derek Cudlipp, who produced three or four identical sets for Churchill. One set is believed be have been buried with the leader.

The false teeth were made just around the start of the war, when Churchill would have been about 65, Hughes said.

The politician is famous for his rousing speeches to the British nation during the war, but his dental issues are less well known. Hughes said Churchill had many problems with his teeth as a child and probably lost some of them quite early. The leader valued so highly the skill of his dentist, Wilfred Fish, that he nominated him for a knighthood.

Churchill served as prime minister from 1940 to 1945 and then from 1951 to 1955.