This section is from the book "How To Intepret Your Dreams", by An Unknown Author.
This is probably the most prevalent dream image that people report. It is disturbing to them because it affects vanity and personal appearance - but only in the dream! a dream about one's teeth falling out usually symbolizes that the dreamer is having a challenge getting their voice heard, or feelings acknowledged.
This may be referring to their conversations with a particular person such as their significant other, boss, or friend; or can be generalized for people who are shy, to include almost everyone they come in contact with.
The dreamer needs to brush up on conversational skills, believe in the value of their own opinion, and learn how to be less intimidated by aggressive people, and become more assertive and make their voice heard. Once they do that, this dream (which is a common recurring dream) should evolve & show improvement...or disappear altogether.
Another theory is that dreams about your teeth reflect your anxiety about your appearance and how others perceive you. Sadly, we live in a world where good looks are valued highly and your teeth play an important role in conveying that image. Teeth are used in the game of flirtations, whether it is a dazzling and gleaming smile or affectionate necking. These dreams may stem from a fear of your sexual impotence or the consequences of getting old. Teeth are an important feature of our attractiveness and presentation to others. Everybody worries about how they appear to others. Caring about our appearance is natural and healthy.
There are cultural interpretations of this type of dream as well. A scriptural interpretation for bad or falling teeth indicate that you are putting your faith, trust, and beliefs in what man thinks rather than in the word of God. The bible says that God speaks once, yea twice in a dream or a vision in order to hide pride from us, to keep us back from the pit, to open our ears (spiritually) and to instruct and correct us.
In the Greek culture, when you dream about loose, rotten, or missing teeth, it indicates that a family member or close friend is very sick or even near death.
According to the Chinese, there is a saying that your teeth will fall out if you are telling lies.
It has also been said that if you dream of your teeth falling out, then it symbolizes money. This is based on the old tooth fairy story. If you lose a tooth and leave it under the pillow, a tooth fairy would bring you money.