most commonly used chart for men is the one developed by
Dr Hamilton and then later modified
by Dr. o'Tar Norwood called the Norwood-Hamilton scale.
The first signs of balding are increased frontotemporal
recession accompanied by midfrontal
recession (type II).
Hair loss in a round area on the vertex follows, and the
density of hair decreases,
sometimes rapidly, over the top of the scalp (types III