Pop singer Ashley Tisdale has issued a public apology for cancelling two concerts in America over the weekend - because she's yet to "fully recover" from a recent rhinoplasty. The High School Musical star debuted her new nose at a gig in New York on Friday night (14Dec07), just two weeks after going under the knife (30Nov07) to fix her severely deviated septum. But she then pulled out of two subsequent shows - one in Miami, Florida, and one in Philadelphia - fuelling fears for her health following the procedure. Now the 22-year-old has confirmed the reason for her no-shows - but reassured fans she's on the road to recovery. She writes on her website: "I'm so sorry I wasn't able to be at the holiday shows this weekend. I haven't fully recovered from my surgery and had to make the difficult decision to cancel the appearances. "When my surgery was scheduled, we didn't think it would be necessary to cancel the shows because my doctor thought I would heal in time. Unfortunately, the deviated septum was more significant than we originally thought so the healing process is taking longer."