“1-2-3-2-1-2 etc”
Something to do with bone loss. Which never made sense to me as you would think once you have lost bone there is no going back. But with increased care (flossing 2 x a day helps) those numbers do get better.
To a point. I have some bone loss around a back molar. At one point it was at a 7. I have been able to keep it around 5 for quite some time. Takes a bit of work. Besides flossing, I use soft picks and go betweens..