Hair transplantation is based on the ‘ theory of donor dominance in Androgenetic Alapecia’.
If a graft is taken from an area destined to be permanently hair-bearing and transplanted to an area suffering from patterned baldness, it will, after an initial period of effluvium, grow hair in its new site as long as it would have at its original site.
This is the scientific basis of hair transplantation. Occipital area is unaffected by balding process and the hairs in this region last a life time.
FUE in Androgenetic Alopecia:
THE FOLLICULAR UNIT GRAFT( FUG) as described by Headington includes 1-4 terminal hair follicles, one (or rarely two) vellus follicles, associated sebaceous gland & duct, insertion of erector pili muscle, peri follicular neurovascular network.