My cats had a checkup last week and one of the lower teeth, the long pointy one, apparently has decay and a small hole in it and has to be removed. I'm just thinking if decay progresses to a degree where there is more hole than there is tooth, it will sort of hang out! You can't necessarily see the hole because it can be under the gumline and if there is tartar and inflammation it would not be obvious. This is what the vet explained to me. It takes a vet to see it, plus somehow they sit still(ish) and open their mouth for HER but they wriggle and clamp their mouths shut when I try to look!