I've never heard of that. The last time I had to go that badly I was feeling it as an uncomfortable tightness in my abdomen. Very unpleasant. But I don't remember the teeth being involved :P
The vagus nerve goes through the lower jaw- it's pretty far back there, so it doesn't usually relate to tooth problems. More often, it's anything from the throat down, and it does impact urination, defecation, and "other" happenings down there.
But, yeah... as an aside to this, pain in the jaw is a common symptom of heart attack. It's actually the only symptom my grandmother had when she had a heart attack- she had the sense to call emergency services and that's what saved her- recognizing that the sudden onset of jaw pain was tied to her heart.
So, you may have a vagus nerve that goes into your jaw more, has unique positioning, or something similar, which would produce more awareness. It's not something everyone deals with, but it's not abnormal. Something to be aware of because that means you may get toothaches when other parts of your body are having issues. It could be your canary in a coal mine, so to speak. If you know what's normal and not normal for you, you may be able to leverage that to know when to get medical help for other conditions. Look at that, now you have super powers. I bet all the other kids will be jealous. ;)
Yes that is because your bladder will overflow up into the root canal of your jaw where your teeth are and your teeth would float away if they were not anchored down by their roots.in the root canal.
Benedict Arnold 