AGA Treat Rev 64 Donor Dominance Theory

What is the key to hair transplantation, the Donor Dominance Theory?

The Donor Dominance Theory is the central concept in this method and is crucia

l in the field of hair transplantation. In this theory, the characteristics of the follicles before transplantation are maintained in the recipient area. The donor refers to the follicles from the donor site, typically located at the back of the head, as mentioned earlier, and dominance implies superiority. In male pattern baldness, the nature of follicles nurturing hair under the skin determines whether or not hair loss occurs. By transplanting follicles individually, the Donor Dominance Theory ensures that even when transplanting one's own hair to an area affected by male pattern baldness, the transplanted hair continues to grow as thick, long, and coarse hair. With a history spanning almost half a century, hair transplantation has proven, through numerous cases, that transplanted hair remains resistant to shedding even decades later.

The crucial point is that only one's own hair is transplanted. It means using one's own hair follicles. For example, suppose an older brother is experiencing male pattern baldness and thinning hair, while a younger brother with similar genetic traits does not face male pattern baldness and has a full head of hair. If the older brother wishes to share some of the younger brother's lush hair, and the younger brother willingly agrees as a favor to his brother, can the transplanted hair grow successfully?

The answer is no. Even if they are siblings, hair from another person does not continue to grow successfully in the recipient area. As mentioned in Chapter 1, hair follicles are the smallest organs in the human body. Transplanting someone else's hair follicles is akin to organ transplantation. Even with close family ties, rejection reactions occur in the recipient area, and long-term healthy growth is not established.

In the case of autologous hair transplantation, where one redistributes their own follicles, concerns about rejection reactions similar to organ transplantation do not arise. As long as they are one's own hair follicles, even body hair like chest hair can be transplanted and established just like scalp hair. Since male pattern baldness does not occur with body hair, the Donor Dominance Theory comes into play.

Since body hair differs in length and shape from scalp hair, the satisfaction level with autologous hair transplantation is comparatively lower. Although there are methods to transplant artificial hair, artificial hair is more prone to rejection reactions than hair from close relatives, leading to frequent issues such as inflammation on the scalp. Consequently, in advanced countries for hair transplantation like the United States, artificial hair transplantation surgery is prohibited. In Japan's guidelines as well, the recommendation level for artificial hair transplantation surgery is categorized as D (not recommended).

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