Making his TV comeback as one of America's favorite film reviewers, Roger Ebert presided over his new PBS series premiere with the help of a cutting-edge marvel or two -- and that's not a reference to movie critics Christy Lemire and Ignatiy Vishnevetsky, newly installed by their boss as the main tastemakers occupying those famous aisle seats.

Ebert's face has been dramatically altered by treatments for cancer in his thyroid and jaw, and over the last two years, developing a prosthetic chin to wear on camera was a painstaking process. "That's not to fool anyone, because my appearance is widely known," says Ebert, 68, in a recent blog entry titled 'Leading With My Chin.'

"It will be used in a medium shot of me working in my office, and will be a pleasant reminder of the person I was for 64 years," he adds. "Symbolically, it's as if my illness never happened and, hey, here I still am, on the show with these new kids. When people see the 'Roger's Office' segment, they'll notice my voice more than my appearance."

And because Ebert's cancer battle has silenced his voice, viewers of 'Ebert Presents: At the Movies' -- produced by his wife, Chaz Ebert -- will now hear his words spoken by different famous voices each week (a Chicago video report seen after the jump reveals the secret).