Bristol Palin admits her recent change in appearance was due to a procedure — but not plastic surgery. The 20-year-old daughter of 2008 GOP vice presidential candidate Sarah Palin tells Us Weekly that she underwent corrective jaw surgery in December, a month after she finished third on ABC's "Dancing with the Stars." Her face now appears thinner, with higher cheekbones and an angular jaw. The new look, complete with Palin losing 5 pounds, was unveiled on April 30 at the White House Correspondents' Association dinner in Washington, D.C. "Yes, it improved the way I look, but this surgery was necessary for medical reasons," she told the magazine for its May 23 issue, which will be on newsstands Friday. Palin said she had the procedure so her jaw and teeth could properly realign. While growing up, she wore braces and a device to help correct an overbite. But she said her dentist warned her that she'd have to have surgery one day. Palin said she is pleased with the new look.