The teeth one is apparently common, I get that too. It starts off with one tooth being loose, and I'm like "oh crap that's not good" then I check the other teeth and they are all loose and in some cases even start to crumble the more I touch them. Sometimes I'm like "I hope this is just a dream" and at some point wake up. There's also times where I've had a dream like that, but involving my hair. I'll be noticing that I'm thinning and I start to touch my hair and it all starts to fall out.
One reoccurring dream I get a lot is school related, they vary but typically it's high school, but sometimes college. Typically at some point in the dream I'm trying to find my locker, or trying to remember my combination or trying to find a classroom. Some varieties of the dream I'm just in the cafeteria with friends, and getting food. There's also some versions where I'm actually on the bus on the way to school. There's also one version where I'll be sitting in class, then suddenly come to the realization that I have not been to math in a long time and then I'm scrambling to try to find my schedule to see if I've been missing it or what. It's always math too. Then I wake up from the dream, and will be pondering it for a bit until I wake up enough to realize I'm not even in school anymore. Apparently dreams like this are also common for many. I guess the school system gives PTSD lol. The few last times I had this dream, specifically the ones where I can't remember my locker combo, I'll be in the dream and thinking "weird, this is like those dreams I always get.. I wonder if this is actually a dream too!". One time I went lucid and just started exploring parts of the school that were restricted. Basically went into the backrooms.
One thing I find interesting in dreams is that there seems to be a common world that all dreams happen in. Buildings, roads etc are different than they are IRL, but they are consistent within each dream.