My mom always told me that dreaming about the teeth falling out is symbolically a very good thing (I usually dream that myself a lot too.) Apparently the teeth stands for different ages in your life, so losing them means you're ready to approach a new "chapter"... The last time I dreamt about my teeth I dreamt that I had a really special one, that kind of curled up in my cheek and looked like a huge shell. And when I lost it I was so nervous the new one that would grow out wouldn't look the same. When I told it to my mum she said that meant I'm nervous about my new busy lifestyle (I have a full time job for the first time in my life) will make me lose my creativity.
I'm sorry if this became to long and nagging; it's just that I think dreams and symbols are so interesting. And I really love this piece of art you've made out of your nightmare!! It is truly beautiful! I have only made one painting inspired by a nightmare of mine, it's called "Last night I dreamt that my father died". It would be an honour if you would like to check it out: [link]
Nightmares, according to Freud, just reflects our fears. Simple and plain. But the mind it's tricky, and usaually don't say thing that... simple. In the teeth case, if you don't mind I say it, it probably means you're scare because there's no "control", that you can't... handle something. Only you would know, of course. And about the blood... It's usually realeated more to life than death, actually. Or is just your mind trying to warning you abour some king of... problem with your body. Or you have too much stress on you. Don't mind me, I was about to say this paint it's amazing, actually XD