If you dream of falling teeth, it means you may be losing something. That thing in reality, can be anything in your current context. The dream imagery of falling teeth is but a metaphor to represent the concept.
If you dream of catching falling teeth, it means your kids will leave home, or die young.
Dream interpretation of pushing out teeth with your tongue:
This is bad. Normal teeth are strong and you can’t push them out with your tongue. If your teeth are weak and not firmly anchored in your jaw, you may feel you can push out your teeth a little, by forcing your tongue against them.