Remember when Mischa Barton was involuntarily committed this past July? Well, we finally found out why. It's because her teeth hurt. That's probably the worst rehab excuse we've ever heard. Why not just go with "exhaustion?"

We all know that "exhaustion" really means that you're partying too hard (see pic above, taken on June 26 as she exited a London club at 3:30am three weeks before her commitment), but don't want to admit it. Instead, you go with the Molar Defense and try to play us as a bunch of patsies. Even Britney was upfront about going bonkers. In this case, the lie is worse than what she's trying to cover up. Here's what Mischa told Time Out New York in her first Q&A since the hospital.

I went through a terrible surgery-a wisdom tooth surgery, all four removed. It was a nightmare. I've never had surgery before-it all went wrong and I had to have a second surgery and it almost delayed shooting because it was a nightmare to me, because I couldn't deal with the thought of not getting there on time. So with the travel, and surgery and prep for the show-it was hell.

So, was it the surgery that made you look all bloated and strung out in the pictures too? We just want to get on the officially party line here. When asked if it was drugs, she said no. And if asked if her hospitalization taught her how to deal with her emotions or the chronic pain from her botched surgery she says, "Not really."

Just for this, Mischa, we're not watching you play a pill-popping model on The Beautiful Life. Ok, that's a lie, but don't insult our intelligence, OK.