Maximizing Graft Effectiveness

There is only a limited amount of donor hair available for transplantation and, in most cases, it is not enough to create, hair-for-hair, the same mathematical density (FU/CM2) that existed before hair loss started. As a consequence, a major challenge in hair restoration surgery is to create the best illusion of density possible at lower than normal, pre-hairloss densities. To do this, the donor hair has to be used as effectively as possible utilizing patterns, distributions and techniques that create the greatest appearance of fullness with the least amount of hair. Equal amounts of hair can appear thicker or thinner depending on how effectively the hair is used.

We perceive a person as thinning when we begin to notice scalp appearing through the hair. In general, we see objects when the light waves emitted by that object reach our eye. Objects of different colors send off different wavelengths of light. On the head, light waves travel to our eye from either the hair shaft or the scalp. Before thinning is noticeable, the light waves from the scalp are blocked by the surface area of the hair shafts interposed between our eye and the scalp. So, before thinning becomes noticeable, we can only see the light reflected from the hair shafts and not from the scalp. At a certain critical point in the progression of hair loss, light waves from the scalp are able to pass through the existing hair and our eye is now able to see the light reflected from the scalp. The contrast that the eye picks up between the scalp and hair is what we perceive as thinning. Any factor that increases the hair's ability to block the light passing through the hair will increase the effectiveness of hair in creating fullness. Some factors (such the angle, orientation, pattern, and distribution of hair) can be controlled and manipulated by the surgeon to maximize the density produced. Others factors (such as hair color, curl and caliber) cannot be changed but are still important to take into consideration as they still influence the final result.

Some of the factors that influence the ability of hair to be more effective at producing density will be discussed in the following sections. These include:

Selective distribution of different-sized grafts
Graft orientation with respect to the scalp (this is influenced by the use of either Coronal or Sagittal incisions to create the recipient site incisions)
The angle of hair as it leaves the scalp
The characteristics of hair (color, curl, caliber)
The patterns used when replacing hair
Using tools that will focus the density in aesthetically critical areas