Eyebrows are a critical facial feature that helps to define the way we look. In many ways, eyebrows are more important to one’s appearance than scalp hair, as eyebrows are in a more central position on the face and serve to frame the eyes (the single most important facial element). Unlike the loss of scalp hair, the loss of one’s eyebrows is not viewed as a natural process and is, therefore, not cosmetically acceptable. Eyebrows may be lost for a variety of reasons including thyroid and other systemic diseases, alopecia areata, burns, tattoos, infections, repeated plucking, congenital inability to grow eyebrows and a genetic tendency for eyebrows to thin, or disappear, over time.
Eyebrow restoration is similar to other hair transplant procedures performed on the scalp, in that, for appropriate candidates, the transplanted hair is permanent. However, because eyebrows have their own unique attributes, eyebrow transplants differ from hair transplants in a number of important ways.
Eyebrow Anatomy and Physiology
The direction of eyebrow hair changes dramatically in different parts of the brow. In the region of the eyebrow nearest the nose, the hair points upward. The hair across the top of the eyebrow points outward and downward. The hair in the lower part of the brow grows outward and upward. This criss-cross growth pattern causes the hairs in the middle of the eyebrows to converge and form a subtle natural elevation running horizontally through the middle of each eyebrow.
The second distinctive characteristic of eyebrow hair is that the hairs emerge from the follicle at a very acute angle so that the hair grows flat to the skin’s surface. This is in contrast to scalp hair where the angle between the hair and scalp can be 45 degrees. The third important feature of the eyebrows is that the hairs grow as individual strands, rather than in the 1- to 4-hair follicular unit grouping that are characteristic of scalp hair.
The fourth distinctive element of eyebrow hair is that the hair growth cycle is very short. This means that eyebrow hair will grow (in anagen) only for about 4 months before it enters the resting (telogen) phase and falls out. In contrast, scalp hair has a growth phase that can last 3 to 7 years, enabling the scalp hair to grow much longer.
Eyebrow Transplant Technique
The most important aspect of transplanting eyebrows is to follow the natural hair direction very closely. This entails very subtle angle changes to recreate the fan-like splay of hair at the medial aspect of the brow and the converging hair direction as one moves laterally along the brow. Most importantly, the recipient sites for the hairs should be made with a very fine-gauge needle that literally slides along the surface of the skin as the sites are being made, as this will insure that the hair will lie as flat as possible on the surface of the skin as it grows.
Another important part of eyebrow restoration is that only individual hair follicles can be used. Since the scalp naturally consists of 1 to 4-hair follicular units, hair taken from this area must be divided up into 1-hair grafts using a stereo-microscope. Technically speaking then, an eyebrow transplant is not really Follicular Unit Transplantation, but rather an ultra-refined form of micrografting. Single hair micrografts, placed into recipient sites that have been created at very acute angles to the skin surface, require a considerable about of skill and experience. In addition, when the patient’s hair is waved or curly, it is particularly important to rotate the hair so that curve of the hair shaft follows the natural curve of the eyebrow.
Four tips for transplanting eyebrows:
Use single-hairs in the transplant, not grafts of multiple hairs.
Hairs should be rotated to follow the natural curve of the brow.
The transplanted hair must be planted to lie as flat to the skin surface as possible.
The transplanted grafts should account for changes in the natural direction of the hair in different parts of the eyebrow, with the upper hairs of the eyebrow pointing out and slightly downward and the lower ones pointing out and slightly upward, creating an interlocking ridge that gives eyebrows their fullness.
Cosmetic Results of an Eyebrow Transplant
Although eyebrow hair transplantation is a safe and cosmetically elegant procedure, there are a number of things to consider before undergoing this type of hair restoration. As with hair transplants to the scalp, the hair transplanted to eyebrows will continue to grow and must therefore be periodically cut. Besides being a minor nuisance, trimming the hair leaves a cut-end that is not as delicate as the fine-tipped end of an untouched hair. In the process of healing, all wounds contract. As the recipient sites contract, they may slightly change their flat orientation and sometimes result in eyebrow hair that is slightly more elevated than one would like.
In contrast to hair transplants, where the donor hair is taken from another part of the scalp and matches perfectly, with eyebrow transplants the hair is taken from a part of the body other than the eyebrows and will thus have slightly different characteristics with regard to both growth rate and appearance. If they are different, then over time, the transplanted scalp hair will slowly begin to approximate the growth pattern and characteristics of the existing eyebrow hair – but it may never totally match it.
The appearance of an eyebrow transplant will mature over the course of a year. At that time, an additional eyebrow hair transplant procedure may be considered. During this interval, the eyebrow can be tweezed and shaped as needed.