Dr. Frank Ryan, the surgeon who performed extensive plastic surgery early this year on Montag, died in August in a one-car accident in Los Angeles, according to reports.
Ryan was 50 years old.
The surgeon was thrust into the spotlight in January when a radically reconfigured Montag announced that she had undergone 10 different plastic surgery procedures in one marathon session.
People magazine reported at the time that Montag's mother was "horrified" by her surgeries.
The magazine quoted an anonymous source "close to the [Montag] family" as saying that Montag's mother, Darlene Egelhoff, "is horrified and having a total breakdown. She can't wait to confront Heidi when she goes home."
But Montag, 23, told "Nightline" in a January interview that her mother knew she was going to have plastic surgery. Montag went on to say that she was even planning to schedule a "mommy makeover" with her plastic surgeon for her mom.
"Actually, she was excited for me and she's asking me ... for her surgery next," said Montag. "So for Mother's Day, I have to ask [surgeon] Dr. Frank Ryan if he'll do the mommy makeover. But I think that she understands. And I think the first surgery was a little more weary for her, and a little more foreign to her, and she was a little more concerned."
Montag had breast implants, a brow lift, botox in her forehead, a nose job revision, fat injections in her cheeks, a chin reduction, neck liposuction and had her ears pinned back.
ABC News reached out to Edelhoff, who declined to comment publicly.
Montag: 'I'm Not Addicted' to Plastic Surgery
Montag caught the public's eye on MTV's "The Hills," and her star continued to rise on the reality show "I'm a Celebrity, Get Me Out of Here!" Now she has released an album -- one that she hopes will turn her into a pop phenomenon.
But Montag's blueprint for stardom is not limited to music. It also includes plastic surgery.
"Yeah, I had my legs liposuctioned on the inside and the outside," Montag said. "But it wasn't really to take out the fat. It was more just to contour the legs. And then I had my back-- scooped out a little bit to help give a curvier look and then a little bit on the sides, too."
Some hospitals don't allow elective plastic surgeries to extend beyond six hours because of complications, but Montag said she spent 10 hours under the knife. She admits the procedures were extremely painful and the recovery taxing.
"I went to an after-care place," Montag said. "And I was in so much pain, and like, literally crying, and just saying, I-- I felt like I wanted to die almost."
We asked her how she would respond to critics who say she's addicted to surgery -- or to fame itself.
"I would say that none of those people know me at all," said Montag. "And that's just a judgment. I'm not addicted."
ABC News' Lauren Effron contributed to this report.