Shape, density, caliber, and curl – let’s demystify the terms!
Everyone’s hair is a unique reflection of their own personal genetic make-up. Ethnicity can influence the characteristics of your strands and knowing how can help you build the best haircare routine possible. Image by Freepik
Every single one of us is born with a unique hair type, one that’s ours and ours alone (unless you happen to be an identical twin or triplet, that is). It should come as no surprise that your ethnic background influences many of the characteristics that make up your head of hair, and understanding your hair’s features can help you develop best practices to take care of it. Below I go over hair characteristics and the challenges that can accompany them (as always, based on research).
How much hair do you really have?
When we talk about how much hair you have on your head, what we’re really talking about is density. Often confused with hair thickness (the diameter of hair), density refers to how tightly hair follicles on the scalp are packed together, not how thick the individual strands are. The number of hairs you ultimately have on your head is determined by density.
Research shows that hair thickness is inversely correlated to density, meaning that finer hair types typically have a higher hair density when compared to thicker and coarser hair types. What does that mean? In simplest terms it means that finer, Caucasian hair types typically have the highest density (~ 100,000 hairs/head). Thicker, Asian hair types tend to have a slightly lower density (~90,000 hairs/head), and Afro-Caribbean hair types tend to have the lowest densities (~70,000 hairs/head).
Both strand thickness and overall hair density contribute to how thick hair looks. Research shows an inverse relationship between hair thickness and density – the thinner the hair, the more densely it tends to be packed, and vice versa. Image by Freepik.
Yes, there are variations. These numbers are averages based on large sample sizes. There’s rarely such a thing as an absolute in science because context is always key. And as to what these numbers mean to how thick your hair appears? Even though hair density tends to correlate inversely with strand thickness (or coarseness), that increased diameter can make less densely packed hair appear as full (if not fuller) than thinner, more densely packed hair types. It’s all a matter of perspective.
As to strand thickness – also called the caliber – Asian hair types statistically have the greatest (80-120 micron diameter for Asian hair versus 65 microns for Caucasian hair), followed by Latino and African hair types, though there is some data that suggests that middle eastern hair strands might have the highest caliber as well as the lowest density. As I said, there’s variation. And hair caliber and density aren’t the only things that affect how full our hair appears. Shape, curl, oil composition, skin thickness, and mechanical properties also factor into how our hair looks.
The shape of your hair follicle determines texture, as it influences how keratin is placed along the growing shaft. Round follicles have a more even distribution of keratin and therefore produce straighter hair. Oval and elliptical follicle shapes lay keratin asymmetrically, which leads to a more curved pattern. As far as empirically observed ethnic trends go, Asian follicles tend to be very circular, Afro-Caribbean follicles are more elliptical, and Caucasian hair follicles are usually oval in shape – but again, these are guidelines. There’s a wonderful mix of textures and shapes out there.
So, what about those curls?
The shape of the follicle influences whether hair will curl (round, oval, elliptical) but the patterns are determined by the distance from the skin that the curl starts. The further under the skin the curl begins? The tighter the curl. Image by wayhomestudio for Freepik
The shape of the follicle is only the first part of defining a curl. The curl patterns themselves are determined not by shape, but by how deep the curl starts under the skin. Curlier hair has a curl that begins right at the follicle, whereas wavier hair types have a curl that begins just below the skin.
How hair type influences a hair transplant
In New York, I have the privilege of working with a wonderful variety of patients from many different backgrounds, and yes, different hair types require different techniques to deliver the most natural results possible.
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Curled follicles are trickier to excise for a hair transplant. It’s easy to accidentally transect a curled follicle bulb as most of the punch tools are designed for a straight extraction – not only are they curved but they tend to be shallower than non-curled hair types. Transection can be disastrous to a hair transplant, as transected follicles may not take. Implantation is also tricky as you don’t want to damage the hair follicle. I use an arced hand movement to follow the curve of the hair and reduce the chance of slicing the graft as I’m excising it, thereby preserving the viability.
Different hair types come with different challenges for transplanting, but they’re balanced out by advantages. Take curlier hair types – follicles can be more difficult to harvest but cover more area and lend a natural hairline. Image by drobotdean for Freepik
There are some real positives to transplanting curled hair – it covers more area (fewer grafts needed) and lends itself to creating natural, irregular hairlines. Scarring is often minimal with this hair type.
A high caliber hair can cause challenges as well. Asian hair has the greatest diameter (80-120 microns), making it the thickest caliber. This means that we often need an extra row of grafts at the hairline to create a natural look. As well as having a high caliber (and possibly due to it), Asian hair types have the highest proportion of single hair grafts (24-30% occurrence versus 14% in Caucasian hair types) meaning there’s less of a need to create single hair grafts. The graft recipient site sometimes needs to be made larger to accept the hair. The size of the hair follicle can lead to challenges as well –Asian hair types tend to be longer (5-6 mm from the skin versus 4-5 mm in Caucasians) which requires a deeper insertion to properly harvest the hair graft. As mentioned earlier this hair type tends to grow perpendicular, meaning we have to be conscious of scars as they can be more visible than with angled hair. Metabolic activity in the bulb also tends to be higher, meaning there can be a risk of grafts drying out.
The best advice I can offer anyone seeking out a hair transplant concerned about hair type? Find someone who understands and has experience with your hair type. Your choice can make a big impact on the eventual outcome!
For those curious about their hair transplant options, visit us at City Facial Plastics to book a consultation or see my before and after gallery.
Best Hair Practices Guide
This list is far from exhaustive but it’s a good place to start if you’re curious over some of the care challenges different hair types face.
Caucasian hair types: Volumizing shampoo 2-3x/week and a volumizing conditioner applied midshaft to ends.
Natural bonus: Natural oils in this hair type add volume and manageability –– additional volume can be added with a volumizing foam or mousse.
Styling challenge: Avoid excess heat-styling which can damage the thinner keratin layers. Try to use lower settings.
Asian hair types: Because hair is less dense, oil and other conditioning agents can buildup and weigh hair down. Managing natural oils with regular shampooing is key. Avoid conditioning and styling products with lots of oils as heavy moisturization can make hair appear flat and greasy.
Bonus step: Regular scalp massages can help manage the scalp’s natural oils.
Styling challenge: Because Asian hair follicles often grow at a perpendicular angle, hair that’s trimmed too close to the scalp can stick out and give the illusion of an oversized head. Long hair that’s not cut properly can also weigh heavy on the scalp, neck, and shoulders.
Afro-Caribbean hair types: The American Academy of Dermatology recommends shampooing hair once a week to every other week. Hair care products can be very drying to this hair type, and moisturizing conditioners are recommended.
Bonus step: Hot oil treatments 1-2x a month can add beneficial elasticity and moisture.
Styling challenge: Use caution with relaxers – the recommendation is for touch ups to be performed no more than once every 2-3 months (max) and only to newly grown hair.
If you press or thermally style your hair, use a ceramic tool and try to keep it to once a week.
Make sure hair braids, cornrows, and weaves aren’t done too tightly to avoid traction alopecia.
Looking for hair care products that can really help your hair look and feel it’s best? My Feel Confident hair care products are launching very soon – sign up to our mailing list to be the first to know!
The content of this newsletter is for entertainment and educational purposes only. This content is not meant to provide any medical advice or treat any medical conditions. Patients must be evaluated by an appropriate healthcare provider on an individual basis and treatment must be tailored to meet that patient’s needs. Results and particular outcomes are not guaranteed.