03/25/2008 at 04:15 PM EDT
High School Musical
star Ashley Tisdale
is finding herself on the defensive again after rumors surfaced last week that she had more plastic surgery.
"People are saying I had another nose job and I did not. That's ridiculous," Tisdale tells PEOPLE exclusively. "I was away in New Zealand filming a movie (They Came From Upstairs
) and so people think I went away to have more work done. But I didn't."
Tisdale, 22, had a nose job in last November
to correct a deviated septum and to smooth out two bumps from when she fractured her nose as a teen. The singer/actress was slammed by critics, saying that she didn't have to change the look of her nose in order to fix her septum.
"[Tabloids] have doctors talk about what they think I did with my surgery, but they did not examine me," Tisdale says. "They don't know what I have inside my nose."
"It's very irresponsible for a medical professional to comment on someone whom they have not examined," notes Tisdale's rep, Scott Appel.
Rumors also recently surfaced that Tisdale, who is in Utah to film High School Musical 3
had a breast augmentation.
"Look at me," she says, laughing. "Does it look like it to you? No! It's ridiculous. I'm not for plastic surgery. I'm not going to get another surgery. I can promise you that."