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Scalp Pathology for the Hair Transplant Surgeon: Donor vs Recipient Dominance Revisited

414 In a previous issue of the Forum, I reviewed Dr. Norman Orentreich’s original article, which established the concept of “donor dominance” in androgenetic alopecia. The finding that scalp autografts maintained their hair growth characteristics independent of the scalp recipient site has been the cornerstone of modern hair transplant surgery. This hypothesis was challenged by Hwang, et al., who transplanted scalp follicles to the lower leg and showed that the survival rate and growth rate of transplanted hairs are influenced by the recipient site when the recipient site is other than the scalp. It is not surprising to see Dr. Orentreich’s name as an author of a fascinating experiment, recently published in the Journal of the American Academy of Dermatology, that compared the growth of balding and non-balding human scalp follicles when transplanted onto immunodeficient mice. Both male pattern and female pattern alopecia were studied. Scalp tissue was removed as 2mm punch grafts, which were subsequently dissected into grafts containing no more than two follicles. All grafts underwent post-operative effluvium and initial regrowth within 7 weeks after transplantation. Measurements were made at 22 weeks. The results were astounding. In male Scalp Pathology for the Hair Transplant Surgeon: Donor vs Recipient Dominance Revisited