I have a lot of dreams where I'm me in another body. This has been going on since I was probably a teenager. What does this mean?

Also, I have epic dreams, I mean they are clear as day and last a really, really long time (or at least seem too in a dream state). When I write them down with all the details I remember they have been up to 25 pages long. Is this common?

Recently I've been having a lot of dreams about my teeth falling out. It really, really bothers me. When I wake up in the middle of the night I have to go brush and floss my teeth. I haven't found a clear interpretation for these dreams, but they seem to be getting more frequent. What do they mean?

Any help would be appreciated. Thank you.