Posting a photo of her injury on Twitter, the Spice Girl explained that she copped the nasty carpet burn during a post-Olympics weekend away in Prague.
"I wish I'd seen the security footage because I bounced off the wall, slid down it, then ate the floor," she joked.
"I've never done that before, ever, ever, ever, it was so embarrassing. I thought I'd broken my jaw, then I thought I'd never be able to talk again, wondering if it would go back to normal."
There was no sign of the injury in last night's pre-recorded premiere episode of The X Factor but we can probably expect to catch a glimpse of the painful graze in weeks to come, unless Network 7's makeup department does a good job of covering it up.
In other Mel B news, rumour has it she might be ditching our Aussie X Factor for a role on the UK version of the show next year.
The singer was already committed to working Down Under when she knocked back an offer from UK producers desperate to poach her for this year's show.
"Mel was our first choice," an insider from the UK X Factor told The Sun. "She was so quick and honest [on Australian X Factor].
"There's a lot of money on the table for her next year."
Let's hope our Australian X Factor producers can offer more! Mel B's an honourary Aussie now, right?