AceShowbiz -

For showing extreme cleavage at Sunday's CNN's Heroes 2011 award, Miley Cyrus gets a bunch of reactions including the assumption that she went under the knife. Three so-called experts have been asked for their opinion on the authenticity of Miley's breasts.

The 19-year-old went to the red carpet event with boyfriend, Liam Hemsworth, wearing a yellow neck-plunging dress by Roberto Cavalli. The busty appearance was topped off with platinum and diamond chandelier earrings and stacks of platinum bracelets by Neil Lane jewelry.

"Her breasts are very nice and round and it looks like she has had them done," cosmetic physician Dr. Tahl Humes of Vitahl Medical Aesthetics in Colorado, told Star magazine "If you look at the volume, it appears she has had a breast augmentation." He compared the photos from Heroes 2011 award to the actress previous'. "Whoever did them did a very good job. She might have had small implants, which is nice, because she is a small girl with a small frame."

Another opinion came from Michael Niccole of Orange County, California's Cosmeticare who said, "It appears that Miley has recently undergone breast enhancement surgery." Eliminating the possibility that Miley had used help in the chest area, Niccole added, "Push-up bras are great for cleavage, but don't help out a whole lot when it comes to the exterior breast volume, which is also what I notice in these photos."

Now, New Jersey-based board certified plastic surgeon Dr. Brian Glaat said the Disney star's breasts appear fuller and show the outline of the implants. "Even a large weight gain would not produce breast enhancement to this degree without implants!" Glaat said.