A brief look at hair characteristics and it’s role in hair transplant surgery
Hair characteristics play a very important role in hair restoration and requires careful consideration before embarking on hair transplant surgery.
The visible part of the hair is called the hair shaft which is a cylinder made up of three parts – the outer cuticle layer, the cortex, and the medulla.
- Cuticle: This layer consists of overlapping scale type cells. The strength of the hair is determined by this layer as well as it’s shape, whether curly or straight. This is the part of the hair shaft exposed to UV irradiation and heat from the sun, chemicals, etc.
- Cortex: This is the part that determines hair colour. The cortex consists of keratin filled cells, and provides flexibility to the hair shaft.
- Medulla: This is the innermost section of the hair shaft and consists of air bubbles and thin cells.
Click here to read more about hair structure and hair loss.
The effect of hair shaft caliber (thickness)
Hair shaft caliber refers to the volume of a single hair. All the hairs on your head contribute to the total hair volume. The bigger the caliber of an individual hair shaft, the larger the total hair volume will become when adding up all the hair shaft volumes. Hair shaft caliber is the single biggest contributor to total hair volume. For every 10 microns that the hair shaft caliber changes, there is a 36% volume effect, either way.
Caliber, curl-and-wave and colour
We can therefore see that high caliber hair shafts with a curl-and-a-wave add much more towards hair volume compared to short straight low caliber hair shafts which contribute the least to hair volume. In hair restoration it is therefore much easier to to create a fuller and denser looking head of hair with curly high caliber hair shafts compared to the challenge of creating density with short straight and low caliber hairs. . Click here to learn more about what makes hair grow.
When it comes to hair colour, the smaller the difference between the hair colour and the scalp colour, the greater the illusion of hair density and on the bigger the contrast between scalp and hair colour the thinner and sparser the hair will appear.