The Tooth about Mischa Barton

Mischa Barton was spotted at the Harrods Summer Sale in London with a more plump face -- and it's reportedly because of a bum tooth!

London's Daily Mail says the 23-year-old had a wisdom tooth removed last month, causing Mischa's face to swell.

When Barton starred on "The O.C.," she was often criticized for being too thin.