ANCHORAGE, Alaska -- 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 April 30 at the White House Correspondents' Association dinner in Washington, D.C. "Yes, it improved the way I look, but this surgery...