"What worries me is the commentary she is making to young girls," he told Us.
PHOTOS: Plastic surgery disasters
PHOTOS: Stars gone too soon
According to TMZ, he was killed after his jeep went over the side of Pacific Coast Highway Monday at 4:33 p.m.
In March, she told Jay Leno she wanted bigger breasts, but "I legally can't right now. The limit is 800cc and I have 700cc." As for other surgeries, she said, "I think I've reached the point [where I can stop]. I think I'm good for awhile. I'm surger-ied out."
Dr. Rey didn't slam her surgeon. "The issue of too many procedures in the operating room have [been debated] and forth," he said, "but he is a great surgeon -- that's not the issue."
Minutes before the crash, he Twittered, "After 25 years of driving by, I finally hiked to the top of the giant sand dune on the pch west of Malibu. Much harder than it looks! Whew!"
Ryan, who reportedly was 50, was trapped in the vehicle and suffered major head injuries, TMZ reports. "The Ventura County Fire Department tried hoisting Ryan using a helicopter, but the attempt was called off," says the site. "Ryan was pronounced dead at the scene."
Dr. Frank Ryan - the Beverly Hills plastic surgeon who famously performed 10 plastic surgery procedures on Heidi Montag in one day -- has died.
VIDEO: Heidi struggles to eat burger because of surgery
A month later,Bape, E!'s Dr. 90210 (real name: Robert Rey) told UsMagazine.com he wouldn't have performed more than three surgeries on the reality star.
The site reports he died of "blunt force head injuries,Coach," according to an initial autopsy conducted to the Ventura County Medical Examiner's Office. A toxicology test is also underway.
PHOTOS: How The Hills stars have changed
The surgeon - who performed on celebs including Gene Simmons, Shauna Sand and Vince Neil - came under fire this year for altering Montag's appearance so drastically.
Last fall, The Hills star underwent nose, cheekbone and chin jobs, as well as an eyebrow lift, breast enlargement and fat injections, among other procedures.
Montag filed for divorce from husband Spencer Pratt last month, citing "irreconcilable differences."
Get more Us! Follow us on Twitter, Friend us on Facebook, Subscribe to Us Weekly
"I am devastated to hear the news of Dr. Frank Ryan's death," Montag, 23, wrote on Twitter. "He was the most amazing person I have ever known. He was an angel and changed my life and the lives of everyone he met. He was the most brilliant talented surgeon who will ever exist. Dr. Frank Ryan changed the world. My thoughts and prayers go out to his mother, family, friends, and anyone who was ever blessed enough to meet him. He is in a better place."