May Myat Noe's photograph was blacked out on the Miss Asia Pacific World website, the word "dethroned" stamped alongside her name.
"She thinks as long as she keeps this crown she's the winner," said David Kim, director of media for the South Korea-based pageant. "She's not."
Organizers said Noe had "lied" and proved to be untrustworthy, but provided few details.
Noe was not immediately available for comment. She planned to hold a news conference at a later time, according to Eleven Media, a Myanmar newspaper.
Hla Nu Tun, who initially acted as her unofficial manager, said Noe and the organizers had disagreed over who should oversee her career. Noe's mother wanted control but so did the organizers, she said.
A half-century of military rule and self-imposed isolation kept Myanmar contestants off the stage of international beauty contests until 2012. When Noe was crowned in May, it was seen as a new beginning for young, talented beauties.
Following her victory, the organizers said they were arranging singing and video deals for her. But they also wanted to change the 5-foot 7-inch teen's looks, Kim said.
One of the pageant's primary goals, he said, is to turn winners into regional superstars: actresses, pop icons, and world-class models.
It was decided that Noe's breasts were too small and could hold her back, and she accepted an offer of enhancements, he said.
"We thought she should be more beautiful ... so we sent her to the hospital to operate on her breasts," Kim said, adding that sponsors picked up the $10,000 tab, as they had for previous winners.
"It's our responsibility," he said. "If she has no good nose, then maybe, if she likes, we can operate on her nose. If it's breasts, then breasts."
Kim said that troubles started from there, with the beauty queen bringing her mother to Seoul for what was supposed to be a 10-day visit but stretched into three months.