|upper left||upper right|
|lower left||lower right|
|upper right||upper left|
|lower right||lower left|
(As you can see, right and left are mirrored in the tables)
Since I like Math, I began to search for an injective function from the Universal number to the FDI. So let's begin.
The FDI divides the teeth in quadrants. The quadrant may be given by
So we multiply it by 10 to shift the number left
Sometimes the numbers increase in the quadrant, other times they decrease. So we need to alternate by quadrant:
For odd quadrants let's pick the constant 8. And for even quadrants, the constant zero:
Now let's have something varying up and down:
Now to get the unit in the FDI system, from 1 to 8, we use the expression:
So, for the final formula we have:
Next time you go to the dentist, just try to reconstruct the formula to take your mind off the pain.