Dreams about your teeth are very common, nearly everyone has them at some time or other; grinding their teeth, clenching their teeth and especially their teeth falling out - the only other thing dreamt as often is hair falling out... they don't usually (unless you
do have bad teeth and your visiting the dentist the next say) have anything to do with the state of your teeth, your dental hygiene, so it doesn't mean your teeth are weak and ready to fall out; still, these dreams will leave you feeling anxious when you wake up, then often quite relieved that your teeth are still there.
Normally when your teeth fall out (during childhood) you have no control over it; teeth are usually powerful tools we can bite with and eat, it's quite hard to live without them, which is why we feel very anxious at the thought of losing them. So, losing your teeth in dreams usually represents feelings of losing power or control over something in waking life, you may be actually losing control over part of your life, or just feel like you are... does that make any sense?