Lea Thompson (Kathryn) and Vanessa Marano (Bay) show their pearly whites to the cameras before chatting about their new show. Vanessa plays Bay, the daughter that Kathyrn Kennish has raised for years. How in the world do you think Bay is going to react when she discovers she was switched -- and Kathyrn isn't her biological mom after all? Find out on June 6 when Switched at Birth premieres!