Janet Jackson probably wasn't smiling Wednesday (July 18), and neither were her Milwaukee fans. The singer reportedly canceled her concert there just hours before showtime after undergoing emergency dental work.

Jackson chipped a tooth and had to have an emergency root canal, according to a spokesperson for her label, Virgin Records. A Bradley Center spokesperson said the accident occurred while Jackson and her crew were setting up the show Wednesday afternoon.

Promoters told fans — some of whom had already arrived at the venue — to hang on to their tickets, as the show may be rescheduled. Friday show at the Nationwide Arena in Columbus, Ohio, is still on, the Virgin spokesperson said.

Jackson kicked off her All for You tour on July 7 in Portland, Oregon, after having to cancel the original opener two days earlier in Vancouver, British Columbia, when a piece of her set failed to arrive in time (see "Janet Jackson Live: Tears, Bondage And Tupac").

(Click for photos from the tour opener.) For a full-length interview with Jackson about her All for You tour, check out "Janet Jackson: Backstage Pass." (This story was updated at 7:48 p.m ET Thursday, July 19, 2001.)