For good result in Hair transplant Surgery Design of Hair line is one of the most important step.Hair line is different in each and every person but there are certain similarities in hair line of same sex .for eg.
Male-With the aging process Hair line starts receding, also hair loss is there in the temporal region. Male have broad face with a slight frontoemporal recession .We can look at the hair line of some celebrities to understand this fact .We can also say that male hair line is more or less M shaped.
Female- hair line is typically placed at a lower level, it does not recede much with age .Fronto temporal angle is also full of hair .These all factors give appearance of narrow fore head. Also it is like inverted U shaped.
Properly designed hairline before hair transplant will give natural look. In male if hairline is planned at a lower level then it will give Unnatural and transplanted look.
Here are some photographs for comparison between male and female hairline.