Many years ago, before the internet, when speaking to patients from far far away places on the phone I would use what I referred to as a ‘Baldness/Donor Ratio’ (BDR).
I would ask patients to use the palm of their hand and use it as a rough measure, placing it over the bald area and the donor.
An extremely rough ratio would be envisaged.
Eg. 2 palms balding area/3 palms donor. Or 2:3
Other parameters are:
- shaft diameter ( sd), fine, medium or coarse
- donor density (dd), sparse, low , medium or dense
- color contrast (cc), high, medium or low
- pre existing hair (pe), zero, very sparse, sparse, low, low medium, etc
With the advent of the internet and immediate photos sent, and the development of body hair, I never pursed the BDR (Baldness/Donor Ratio) classification as a means of trying to understand what is going on.
After all, photos should tell the whole story, together with the Norwood Scale.
But obviously, there is some confusion here, with assessing and comparing Michael and Bobman.
So I am resurrecting the BDR, suggest that using a thin cloth, paper or even plastic with a marker, one can ROUGHLY trace out the relative balding and donor area. It is at least more accurate than the palm.
Now I know that Michael’s balding area is at least TWICE the size of his donor. The balding area/donor area ratio is 2:1, or just call it 2.
So Michael is:
BDR 2/ sd FINE/ dd MEDIUM/ cc medium/ pe zero
Now, I have not seen Bobman in person, but from the photos, I think the balding area and donor areas are roughly the same., a 1:1 ratio., or if you like, BDR 1.
So Bobman is probably:
BDR 1/ sd COARSE / dd DENSE/ cc medium/ pe zero to sparse.
I find thinking in terms of the BDR classification helpful because it accounts for different head shapes.
The Norwood scale gives an overall guide, but it shows only one head shape, and as we have seen here, there are countless variations of shape and donor which ultimately determines what is and is not possible.
Dr Ray Woods