In the wake of Miley Cyrus's busty appearance at Sunday's CNN's Heroes 2011 award, a trio of experts told Star magazine that there's a strong indication the Hannah Montana star went under the knife to achieve the voluptuous new look.

Cyrus, 19, turned heads at the event as she walked the red carpet in a yellow Roberto Cavalli dress with her boyfriend, Liam Hemsworth.

"Her breasts are very nice and round and it looks like she has had them done," said cosmetic physician Dr. Tahl Humes of Vitahl Medical Aesthetics in Colorado, using shots from the event provided by the magazine. "If you look at the volume, it appears she has had a breast augmentation.