Did Kate Mulgrew really wear a wig?!? For the whole show?
She must have done. In season 2 episode her hair goes bob-like, in the next one after its bunned up again and long. Either Kate Mulgrew grew ten inches more head hair in a week or she used a different wig.
This sort of thing crops in later seasons, where the bob would grow shorter or longer with each episode. At least in DS9, Terry Farrell and Nana Visitor did not wear any wigs...