Finally, at the risk of offending original aspect ratio proponents (I'm one of you... really), for any of you who own 16:9 displays, it's safe to soft-matte the film to 1.78:1, filling the width of your screen linearly. The film will remain well composed with no instances of heads being unceremoniously lopped off.This is wildly incorrect. Them! was intended for 1.33:1 exhibition with no matting involved.
Doing so results in a very poor composition and an incorrect aspect ratio.