Scalp Micropigmentation (SMP), A Useful Treatment For Hair Loss

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Scalp Micropigmentation (SMP), A Useful Treatment For Hair Loss
Jae P. Pak M.D., Jino Kim M.D., William R. Rassman M.D.

A concealer is a product applied to the scalp to reduce the visual contrast between the color of the hair and the color of the skin. This can be done by darkening the skin with powders, pastes or paint like substances, thickening the hair shafts with a keratin like materials or dying the hair to bring its color closer to the color of the scalp. Concealers are used by men and women with thinning hair or genetic patterned balding. When the tattoo is applied to the scalp, it becomes a type of permanent concealer. The first recorded medical use for a tattoo as a concealer was published by Traquina (1) in 2001 but its use was crude and easily detectable. The refinement of the process we call Scalp Micropigmentation (SMP), require that the tattoo pigment be placed in micro-dots of less than 1mm in size and spaced approximately 1mm apart, similar to the distance between follicular units evident on a shaved scalp.

Scalp Micropigmentation (SMP) is like a stippled painting and, as such, it is an art form. The placement of the pigment dots vary with the targeted goals of the surgeon (artist) and the patient (2). Although we initially believed that the mathematical density of the dots for SMP should approximate the follicular unit density in our earlier experience, we have since come to realize that the actual distribution of dots is not a purely mathematical constant tied to the follicular unit density of a particular patient. When used to address deformities of the hair and scalp, we find that we must blend the pigment with the blemishes and scars found in our patients. What needs to be done is based upon the ‘soft’ requirements of the art form which best defines the dot size, density and color of the pigment. The intensity of the dots and how they are worked into the scalp, gives shade and texture to the area being addressed. The requirement for each area of the scalp may vary based upon many factors including (a) the presence of scars and/or hair, (b) the smoothness and thickness of the scalp, and (c) the color of the skin and hair.

Men and women have the option to control their hair length or for men, to shave or buzz cut their hair. Creative hair stylingtechniques have been adapted by many balding men and women to hide their thinning or balding problems. Shaving the scalp has been an acceptable styling option for balding men, however, when scars are present, the shaving options often disappears. In our 2011 International Society of Hair Restoration Surgery (ISHRS) publication and presentation, SMP was presented for the treatment of many medical and surgically induced scalp problems such as: autoimmune diseases such as alopecia areata, genetic hair loss, surgical scarring from a variety of surgical procedures including strip scarring from traditional hair transplant procedure, old punch graft donor sites, FUE scarring, craniotomy scarring, and scars from scalp reduction surgery.

The use of SMP has great value to augment a hair transplant in the many patients who do not have enough hair, where the hair supply does not meet the need for hair. SMP can also be an alternative to hair restoration surgery in some male patients who do not want to have a surgical procedure to treat their balding, or the female patient who is thinning and may decide to use SMP as a permanent concealer. In some patients with massive scars from old plug grafts and multiple strip surgeries where the donor hair supply is completely depleted, there are no traditional options available short of a full helmet like wig so SMP offers options where none exist. In some male patients, the best option for SMP in men who do not have enough hair for good coverage, is to shave their head completely. A balance also exists where the doctor may be able to design a strategy where SMP can augment a hair transplant. When using SMP for this purpose, there must be some hair present. If it is done when there is not enough hair density to obscure the background dots, then the dots will easily be seen through the thin hair. The design criteria for using SMP as a background for thinning hair requires a specially designed strategy for each patient and varies with each problem being addressed.

The SMP process looks amazingly simple and in concept it is simple, but the techniques that we developed must be customized for each patient. There are many variables in performing SMP that makes this process more of an art form than a science. Bleeding of the pigment colors into the skin is the number one problem confronting the surgeon performing the SMP procedure. The variables in the artist’s hands include: the size of the needles used (individual needle width we use is 140 microns), the number of needles used in the process (we use between one and three needles), the depth of needle penetration (this varies up to ~2mm depending upon the thickness of the epidermis), the duration of the penetration (usually less than 1 second), the puncture cycling of the needle (cycled at a rate of 100-150 cycles per second), the type of pigment used (often mixed by the surgeon), and the incident angle of the needle entering the scalp. There is constant fine tuning of this process as the artist creates the end-product.

Once the first SMP session is completed, the surgeon is able to assess the stability of the pigment and whether or not the pigment will migrate or “bleed” into the surrounding skin. It is quickly recognizable as the pigment is often not stable. The “bleeding” of the pigments into the surrounding scalp changes both the size and the color of the dot. The human body has a tendency to ‘attack’ the pigment in a foreign body type of reaction. As a result of these changes, it often takes more than one procedure to produce a relatively stable result. A typical patient will come back for additional treatment sessions in a period of a month or so, to refine the appearance of the pigment. Exposure to the sun can impact the color and the size of the dots. It is important to explain to the patient that there may be a blue or green tint to the pigment. The greenish color of the black pigment is similar to how the red blood vessels appear green under the skin where the increased absorption of the red spectrum of light gives rise to a phenomenon explained by the trichomatic theory of color vision(3), i.e. if you absorb the red color you will perceive a green hue. The provider performing this procedure must explain this to each and every patient in the disclosure of the informed consent that every patient must sign prior to undergoing the SMP process.

The informed patient often asks about the graying of their hair. Like any tattoo they ask if their hair grays, will highlight the pigment colors of the SMP process making it detectable on a social level. If they shave their scalp, this is not a problem, but if they allow their hair to grow out, then dying the hair may have to be considered if the color/contrast becomes a problem as the patient ages. Because of the high variability associated with the elements in performing SMP, many doctors and tattoo artists tend not to offer this service. Patient deformities created by inexperienced operators will, for the most part, be permanent. As we tell all of our patients, this is a permanent process so that they must be careful to select an experienced person to perform the procedure. The only option for a poor result may be the use of the lasers to remove the pigment, but this process may take many sessions to adequately reverse the process and the reversal is not guaranteed. Also the use of Lasers comes with its own set of precautions (e.g. permanent hypopigmentation) and there are circumstances whereby some people are not ideal candidates for laser procedures. The laser of choice at the time this article is written is the Q-switchd yag laser.

SMP is an art form and like any art form, good planning and execution is critical to the success of the process. The goals for this art form vary with the problems being addressed. For the person who wants to shave their head and maintain a shaved head look, the pigment dots must mimic and blend in with the areas around the head that have hair. The hairlines are crucial to making the process look natural so the leading edges must be graded and appear as if there is a transition zone between the forehead and the hair. A natural look requires a variation in pigment density and distribution as well as size. Straight lines and uniform dots of pigment are a dead give-away that the process is a tattoo. Many patients will ask for a bold, angled, artistic look that gives them a unique style that is not found anywhere in nature (e.g squared front). These patients must be made fully aware of the implications of permanency for the style they choose before going ahead.

For use as a permanent concealer application with a person who keeps their hair longer, the balance of blending hair and dots is a real art and there is no substitute for experience in doing it. Variables such as (1) the closeness and size of the dots, (2) the color of the hair and the pigment selected, (3) the amount of hair that is present, (4) the blending of the hair and the dots, (5) defining the problem being targeted, (6) understanding the patient’s goals and (7) setting patient expectations is a complex balancing act for any physician. Like any art form with many variables, multi-variant analysis is in the art, as it can’t be defined by the mathematics of the process.

A common complication for the operators is the development of flexor pollicis longus and flexor pollicis brevis bursitis or muscle strain which is very difficult to treat. Carpel tunnel problems also arise in those performing the procedure. Additionally, the inks identified should be cultured frequently, as reports of contaminants in the ink causing infections are not uncommon in some tattoo parlors(4). Pigment sourcing, storage and overall management must be understood by the surgeon. Most of the pigments contain various elements including lead and arsenic and there are few regulations in this field that protect the average patient undergoing a tattoo procedure. The Birmingham City Council in the UK determined that heavy metal levels in cosmetic tottoo products above the following values (Lead: 20 ppm, Arsenic: 5 ppm, Cadmium: 5 ppm, Mercury:1 ppm) are considered technically avoidable. The FDA in its publications “Protecting and Promoting Your Health” list many problems produced by tattoos (5). The FDA suggested the need to investigate the tattoo industry to determine if guidelines are appropriate; however, this has not happened yet.

Due to the lack of regulations governing this industry, the onus for patient safety and education is in our hands. Any patient undergoing SMP should have their tetanus vaccinations up to date and the pigment should be tested on the patient’s skin prior to performing any tattoo procedure as allergy to the metals in the pigment can be a problem if it is present. All pigments should be regularly cultured. A reliable source of pigment is very important as many pigments may contain a wide range of known toxins and carcinogenic compounds. Storage of pigments is crucial and they should be refrigerated at 4 degrees Celsius. In Europe, where there are minimal regulations on the pigments used in cosmetic tattoo, it is forbidden to use any pigment that has a preservative in it.

We perform the procedure under hygienic conditions using standard precautions such as gloves and masks. Preparation of the scalp by cleansing with a shampoo to remove excessive oil on the scalp and preparing the site by wiping it with 70% isopropyl alcohol helps to eliminate or minimize the occurrence of infection. We anesthetize the area using local anesthesia to address the pain that the procedure produces. We use 0.5 Xylocaine and 0.25% Marcaine in combination in a ring block. The anesthesia often lasts throughout the entire 6 hour procedure. The dermagraph (hand unit) has between one and three needles measuring 140 microns in width each. These needles are disposable and a new one is used for each and every patient. Needles cycle from 100-140 cycles per second. The depth of the needles varies with the depth of the epidermis, and the smoothness and softness of the skin. Needles are usually held in the skin for fractions of a second but this varies considerably in each area being treated. The angle, where the needles enter the skin also varies significantly. The sizes of the pigment dots are less than 1mm and they are not consistent in size. The art dictates dot size. The density of the dots varies with the goals targeted for each particular area being treated.

The occurrence of pigment migration (‘bleeding’) in the surrounding skin can merge from one dot to another. This process is most often caused by repeating the procedure too often. Many patients will try to push the surgeon for repeat procedures and it is important for the surgeon to convey the importance of patience and sticking to the overall plan to minimize the chances of pigment migration. Poor technique (e.g. the surgeon who does not adequately control the depth or the length of time the needles are in the skin) causes significant problems in dot detection. We have seen pigment bleeding which has been significant in a small subset of our cases. When this happens, the use of a laser to ablate the pigment may be the only option available for the patient. Good patient education and communication is critical. Many patients who come to us have developed a simple view of what they need and will often try to direct the process. We have a constant back and forth with many patients finding a middle ground between what they want and what we believe will work for them.
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Los Angeles Hair Restoration Surgeon