Dr. Orentreich also noticed that hair transplanted from the back and sides of the scalp were not affected by traditional hair loss like the hair found on the top of the scalp. This led to Dr. Orentreich publishing a paper describing his “Theory of Donor Dominance” in 1959. This theory stated that hair follicles unaffected by androgenic alopecia would continue to grow in bald or balding areas previously affected by hair loss. It was this discovery that opened to the doors to over sixty years of hair transplant surgery in every developed country in the world. Once the medical world learned that hair transplanted from specific regions of the scalp would continue to grow unaffected by the causes of male patterned hair loss then the popularity of the procedure skyrocketed.
During the history of hair transplant surgery and hair loss treatments up to this point there had never been an official classification system for reference. In 1975 O’tar Norwood of Oklahoma City, Oklahoma realized this and set out to create such a classification system. Dr. Norwood gave us the Norwood Hair Loss Chart. This has become the world standard for evaluating and classifying the multiple stages of hair loss due to androgenic alopecia. The chart starts with documenting the most mild of hair loss stages to the most extreme with multiple stages listed in between. It is understood that this hair loss chart does not describe every level of male pattern hair loss but it does address the most common and has so far withstood the test of time for over forty years.
There were additional methods of surgical hair restoration that were developed in the 1970’s but they cannot be considered true hair transplantation as there is never a complete separation of hair bearing tissue from the scalp. One method of hair restoration is referred to as the “flap” procedure with multiple variations available depending on the doctor performing it. The flap was first introduced in the 1930’s but it wasn’t until 1969 when Dr. Jose Juri of Argentina made the procedure more palatable for patients and other doctors alike. The procedure involves moving a long and narrow strip of hair that is cut away from one side of the scalp. Ninety-five percent of this strip is physically removed from the scalp similar to a modern follicular unit strip surgery but it is left attached on one end. This end is twisted to allow the strip to lay across the frontal scalp inside of a new incision designed to accommodate this new strip of hair. The procedure has been widely discarded and it is not known if any doctor still performs this procedure. It has been noted as being dangerous for the patient due to the excessive amount of bleeding and relatively high chance of scalp necrosis. The second method introduced in this time frame is the scalp reduction. This procedure was more straightforward than the flap and involved the simple, and logical, removal of bald scalp to address hair loss. Once the bald scalp tissue is surgically removed then both sides of the wound would be pulled together resulting in an immediate cosmetic improvement. This procedure also is no longer performed and is considered to be dangerous due to the high probability of severing larger arteries and the potential for necrosis if incorrectly performed. The result for the patient also made normal hairstyles difficult and it left behind a scar pattern that, if seen, identified that a scalp reduction had been performed.