I've had these nightmares too after a particularly stressful day at the pool, like when I have to manage a difficult group of kids or when I'm worried about an important competition. I've woken up several times with the same panic you described! And the truth is that in most cases it's really linked to anxiety and the loss of control we feel in our waking life.
But here's the thing: be really careful not to let yourself get terrified by the esoteric interpretations you read around! There's so much stuff on the internet saying that dreaming about your teeth falling out means death, illness, disasters... it gets into your head and then makes the anxiety itself worse, creating a terrible vicious cycle. Psychological research actually says that these dreams reflect a real state of anxiety, changes in your life, or simply the fact that your brain is processing stress. It could be linked to fears of aging, of not having control over something, or maybe you've just gone through a period where you felt powerless. Even practical issues like bruxism (grinding your teeth at night) can trigger these dreams!
The important thing is to ask yourself: what was worrying you yesterday or over the last few weeks? Do you have situations where you feel you don't have control? Maybe it's just your brain telling you that you need to relax a bit! If it keeps repeating itself frequently, then maybe it's worth thinking about what triggers this anxiety and facing it directly, rather than fearing the dream itself.