The Important Characteristics of Hair
With further evaluation, we note that there are other players that have a part in determining the difference between a “good” donor hair and a “great” donor hair. Some factors play larger parts than others, the primary characteristics of hair that a transplant center looks at are a hair’s caliber, the hair’s texture and the hair’s contrast.
Caliber refers to the actual size of the hair shaft, where the area is defined as A = π r2 to define the area (A). Coarse hair often provides a better result in one session than finer hair. From a measurement standpoint, fine hair is normally between 38 to 41 microns with coarse hair falling around 80 microns in diameter. Evaluating the caliber of the hair helps the transplant team to determine the number of follicular units that will be necessary in the transplant procedure.
Texture refers to the ‘lay’ of the hair in transplant terminology, not the feel of the hair. This defines how the hair naturally acts: Is the hair wavy? Does it lay straight? Does it curl normally? Is it fine or coarse? We often find that individuals of African descent have hair that has a greater volume. This is due to the hair’s coarse and varying waviness, which covers for a lower density of hair. This is the opposite with individuals of European descent who, on average, have fine, straight hair which has a lower volume than coarse hair but covers in higher density.
Contrast is the last characteristic and this is the color of the hair as compared to the skin tone of the individual. Black hair will look thinner on lighter skin but thicker on persons with darker complexion; less contrast – equals thicker looking hair.
