The Royal was PhotoShopped like the American stereotype of a Brit with bad gnashers for a special issue of the politics and arts publication The New Republic about the future of Britain.
The 30-year-old, who is expected to attend Sunday's Wimbledon tennis final, appears in front of a tattered Union Jack alongside the words, 'Something's Rotten. The Last Days of Britain.'
Inside are several articles about the state of the United Kingdom ahead of this summer's Olympics which have sparked outrage online.
Last year the pearly white Duchess spent thousands of pounds having her teeth polished and turned to give her the perfect smile.
French dentist Didier Fillion used a hidden brace to make Kate’s teeth appear a little out of line, un-American and therefore beautifully natural.
'He did some little micro-rotations on Kate,' his dentist Bernard Touati revealed. 'That’s why they look so good – because they are not perfectly aligned.
'The problem in the United States is they have very artificial vision. But what we like is a natural healthy smile, but not artificial.'
Dr Fillion, also an expert in polishing and whitening teeth, has a clinic in London’s Wimpole Street as well as in Paris and Geneva.
Creating the perfect smile can take the Frenchman anything from six months to two years and costs from £4,000 to £11,000.
Brits having bad teeth is a staple of American humour about the UK. For example, in one episode of the hot comedy The Simpsons Lisa was shown The Big Book of British Teeth by her orthodontist.
One commenter said: 'Not cool. I am not an imperialist (not even close!), but she seems to be a genuine person. She is young, beautiful, and privileged. Apparently grave sins to many people.
'Yet I wonder if these are the same critics who keep up on the Kardashians, or whatever flavour of the month Hollywood squirts out.
'She is a person who did not deserve this low blow. Shame on them. I will wouldn´t even think to read anything from them ever again.'
One poster said it was 'absolutely ridiculous' and another said, 'the magazine should be sued for libel'.
Lee, from Vancouver, said: 'What else an one expect from a Republican magazine, they probably dislike themselves. Satire or not, it is still very disrespectful.'
Another poster said: 'Cheap shot. They know she will remain dignified and not say a word, allowing them to "get away with it".'
The magazine is on news stands now in the State.
Clarence House refused to comment.
