By Michael Ausiello
Updated February 11, 2010 at 12:00 PM EST

Kathy Najimy is about to sink her teeth into a piece of Ugly Betty history.

The funny lady has been tapped to play the orthodontist tasked with removing Betty’s trademark braces, sources confirm to me exclusively.

Najimy succeeds Modern Family‘s Jesse Tyler Ferguson, who played Betty’s original metal specialist in season 1 (and who returned briefly last month).

Najimy will also play a pivotal role in the episode’s It’s a Wonderful Life-esque fantasy subplot. Per an Ugly insider, her character will serve as the guardian angel who shows Betty what life would have been like had she been blessed with perfect choppers.

Najimy’s episode is slated to air on March 24, three weeks before the show’s series finale.