You put/tie your hands behind your back, lean forward and extend your front teeth in an attempt to prepare to do a cartwheel. Using your TEETH as leverage only (not your hands at all), you do the cartwheel, having your teeth hit the ground instead of your hands. This can be done in times of utter excitement or even disappointment. It is to suggest that you are overly emotional about something.
I just won the lottery! I feel like doing toothed-cartwheels from NJ to CA!