I've never seen this is any of my older cats, maybe they broke due to age? It will be interesting to see what your vet has to say.

My old girl Ms Fluffy had a chipped front canine tooth. She was an indoor/outdoor kitty too, so I never knew if it was from a fight or some accident. It never bothered her. I'd be more concerned about the swelling on your kitty's chin which might indicate an infection from one of the broken teeth. Good luck. Let us know how she is doing and what the vet says.

I've had 3 cats that broke bottom teeth and it's fairly common. Just like humans, it might be exposing raw nerves and be extremely sensitive and painful, but cats don't show pain so you'd never know. If it's a very old break, it might not hurt anymore but it could still be a source for bacteria to enter their system (I was at the vet last week for this!). The vet will most likely suggest pulling the tooth (this does have negatives but it's more affordable than sending your cat to a 'dentist' and having a root canal (which I'm doing soon). The bacteria getting in could cause other more serious problems, just as it does for us. There is a chance this is an old break that isn't low enough to cause problems but your vet should know. Because of the swelling, I imagine it's new and pretty painful (sorry to emphasize pain but so many people don't think of getting their cats help unless they are showing discomfort.. animals in the wild who show pain or weakness become prey, so it's instinctual for cats to hide it. Dogs are more domesticated). I realize you have a vet appointment so this obviously isn't something you needed to hear.