Follicular Unit Transplantation (FUE)

Harvested by Strip Method: the State of the Art 1993-2003

         Following the Example of Nature

         Only in the early 1980’s was it been recognized that hair grows not singly, but in specific anatomic units that are called follicular units (FU’s) . These consist of one, two, three, four, or rarely five terminal (mature) hairs, one or two vellus (fine) hairs, a discrete nerve and blood vessel supply, a connective tissue sheath, sebaceous glands, and a tiny muscle known as the erector pili. These FU’s are the natural groupings of the hair, the way it normally grows. It seems intuitively obvious that a natural transplant would follow the form of nature and use strictly FU’s. This has, unfortunately, not been the case.

         It would be expected that using this method would allow us to create the most undetectable result, and also allow us ease in following the natural angles of emergence from the scalp. These angles at which the hairs exit the skin are quite important, as they vary widely depending upon the area of the scalp we are observing.

         Also, improved survival may result from this technique. Consider the old, large plug techniques. The recipient site was actually created using the same type punch that was used to harvest the graft. In other words, tissue was removed. This not only created the potential for scarring and “cobblestoning”, it could compromise the blood flow beneath the scalp as well. In addition, the size of the grafts themselves could limit the flow of blood and oxygen to the hairs in the center of the graft, leading to “donutting”. On the other hand, using FU’s requires only a tiny recipient site in the scalp; we often use only a hypodermic needle to make these miniscule slits! Thus, healing is much quicker, there is less post-operative evidence of the procedure (even the next day), and there is minimal excess tissue subject to scarring and other complications.

         Minimizing Donor Hair Wastage: Mathematical Planning

         Research has shown us that for Asians and Caucasians, the density of follicular units, regardless of the number of hairs they contain, is about one per square millimeter (1FU/mm2). For African type hair it is less, approximately 0.6FU/mm2, although this is more than made up for by the preponderance of three hair FU’s, versus two hair FU’s in Asians and Caucasians.

         We can directly measure not only the FU density, but the hair density as well, by using a tool called a densitometer. With small areas of hair clipped short, a fixed area is observed under bright light and magnification. Then, we can calculate the appropriate numbers, for example: we can look at the density of FU’s and hair in the center of the back of the head, over the ear, and halfway in between. If the numbers average 1FU/mm2, and 2 hairs/FU, and the patient will be receiving 1500 grafts, then we can calculate that we will need to harvest about 15 square centimeters (cm2) from the back and side of the head to give us our required grafts. We can also assume that, given a 20% occurrence of single hair grafts in those with average density, our 20cm2 donor strip will provide us with about 300 single hair grafts, which should be enough for our hairline transition zone.

         Moreover, we can use calculations to plan for the future. The average, non-balding person has about 100,000 hairs on the scalp. This would translate to 50,000 follicular units (FU’s). The “permanent zone” comprises about 25% of the total scalp; therefore, there would be one-fourth, or 25% of these total 50,000 FU’s in the permanent zone, which would equal 12,500 FU’s. We know that about half of the hairs in an area must be lost before there is any appearance of balding, so we could safely harvest up to half of the permanent zone FU’s, or 6,250 FU’s. This gives us an idea of the viable, reasonable donor reserves that a given patient has for current and future transplantation.

         It is important to realize that the amount of coverage and density that a given person achieves with FU transplantation will vary not only according to their donor density and scalp laxity, but also according to their hair characteristics. This is another point where art meets science in the field of hair transplant surgery.

         Hair Characteristics in Follicular Unit Transplantation

         The characteristics that are most cosmetically important are: hair color (especially relative to the underlying skin color), hair curl (or lack thereof), and hair caliber, or cross-sectional area (in other words, is the hair shaft itself fine, or coarse). The artful hair restoration surgeon will take all these factors into consideration when planning a procedure, in order to give the greatest aesthetic benefit to the patient, with the minimal use of the limited donor hair.

         Hair caliber, or cross-sectional area is actually more significant than density in its ability to “cover” bald scalp. Remember that the appearance of baldness is actually due to light penetrating past sparse or absent hair, and then being reflected off the shiny scalp. The more hair that is in place to block the light, the less the appearance of baldness will be. It can be mathematically shown that doubling the caliber of hair would do more to block light than doubling the density. However, there are other important factors.

         One of these is the degree of curl. Generally speaking, the more curl or wave the hair possesses, the more coverage it will grant the scalp. An excellent example of this phenomenon is found in African-type hair. This hair tends to be tightly wound or kinky, which may be an evolutionary adaptation to protect the scalp in hot climates. Although African follicular unit density tends to be lower than that of Caucasians or Asians, (0.6 FU/mm2 vs. 1 FU/mm2), the curl characteristics lend this type of hair wonderful coverage properties, as it tends to stand thick and mat-like above the scalp, thus blocking much light. Also, an added advantage is that African hair tends to occur predominantly as three hair units, rather than the two hair units characteristic of Caucasians/Asians with average density.

         Hair color, especially as it relates to underlying skin color, is also of great importance. The less contrast there is between hair and scalp, the better the potential for coverage. A blond person with light skin, like someone of Scandinavian origin, appears bald only after significant hair loss has occurred. This is because the observing eye sees a high contrast as standing out in stark relief, and areas of low contrast blend together.  So even though many Asians have good density and excellent hair caliber (coarseness), they may be challenging hair transplants. Imagine dark, straight, coarse Asian hair contrasted against relatively light scalp skin; the eye notes the contrast, and sees the light that has been transmitted.  The eye follows the straight hair shaft right down to the scalp, and it appears balder than in someone with more favorable hair characteristics.

         We can see, therefore, that a combination of many factors play a part in determining who will be a poor, good or excellent candidate for hair transplant surgery with follicular units. High density is great, but unfavorable hair characteristics may attenuate some of the benefits of this density. On the other hand, someone with curly, coarse, salt-and-pepper hair (very good characteristics), but with poor donor density and a tight scalp, may also not be the ideal candidate. This is where the artistic, knowledgeable hair restoration surgeon really shines: knowing how to work with the positive resources the patient does have, to insure the best possible outcome for the present and the future.

         The Recipient Incisions

         It is without question that, of all current graft types, follicular units can be placed into the smallest incisions; consequently, they can be placed in closer proximity in the scalp. Although it is not necessary to come close to the patient’s original density when transplanting, there is a certain minimum required to obtain coverage; also, the hairline especially needs closely, although somewhat randomly, placed single hair grafts to give the illusion of graded density.

         Small incisions, moreover, simply heal more quickly than larger ones, and the grafts placed are less likely to suffer from blood-flow and oxygen deprivation. Any incision can damage the circulation of the scalp, cause scarring, and effect wound healing, hair growth, and even the potential for subsequent transplantation. In addition, small recipient sites, made with needles or micro blades, conserve the normal matrix structure of the scalp’s connective tissue. This allows the FU’s to fit snugly within the created sites, avoiding dislodgement, and promoting quicker healing and immediate nourishment of the grafts from local blood supply. We discussed earlier the slow and repetitive process of using large, standard grafts; only so many could be placed at one time. With follicular unit transplantation, however, sessions placing as many as 2000 to 3000 grafts at once, and more, have become routine for us. For many patients, this may be the only procedure they ever need! 

         Large Sessions: The Rationale    

Let’s talk for a moment about large sessions. As it has become apparent that excellent growth can be realized with large FU sessions, other benefits have become manifest. For one thing, it advances the hair restoration process expediently. Most patients have no desire to get ensnared in a lengthy, repetitive series of treatments that they might even have to terminate prior to completion. A large session of FU’s, in some patients, can create a natural, undetectable result; this transplant can stand on its own, and continue to look natural even in the face of further hair loss, and without the necessary need for further work. In short, the process is just plain expedient and efficient.

         Also, every time a procedure is done, the donor area is “violated”. One large, single strip harvested from the donor area will, by definition, create significantly less scarring, hair loss, and distortion of remaining hairs than will multiple, small strips, or, even worse, punch grafts. Minimizing the number of harvests, careful suturing and closure of the donor site, and close attention to harvesting technique can be invaluable in preserving precious donor resources; this is important not only in the event that further transplantation is desired, but also in preserving the cosmetic integrity of the donor area. We will discuss the often forgotten and underappreciated donor area at length in a subsequent section.

         The possibility of telogen effluvium must also be considered with any hair restoration surgery. This is a rapid loss of hair that occurs in the area of the surgery, among hairs that are in the telogen, or resting stage. These hairs will generally grow back, unless they are severely miniaturized hairs that would be naturally lost within a short time anyway. Since it is not uncommon to be placing incisions and FU’s between and around miniaturized hairs like these, there can be significant loss. If large numbers of FU’s are placed during a session, then at least the patient can know that the hairs that will grow in a few months later will be strong, solid terminal hairs, and will compensate for the effluvium loss.

         One other rationale for large sessions considers the need for different types of FU’s (i.e., singles, doubles, etc.). As we pointed out in the section on mathematical planning, only a certain percentage of FU’s will be single hair FU’s. This is quite important in planning the hairline reconstruction, which required relatively high numbers of singles. If too few FU’s are harvested, then the number of singles, for example, might fall short. In this case, the only options are an incomplete hairline, or “creating” singles by dividing 2 or 3 hair FU’s, which is definitely less than an ideal technique. Indeed, if we claim the primacy of the follicular unit, how can we then rationalize breaking them up?

         Insuring the Integrity of Follicular Units

         Let’s consider for a moment the other techniques that we think are integral to the follicular unit transplantation process. One is single strip harvesting, and the other is stereo-microscopic dissection. Without these companion techniques, the procedure may be called follicular unit transplantation, but it is a pale, inefficient imitation.

         As its name implies, single strip harvesting is the method by which a single strip of hair-bearing scalp is carefully, indeed, painstakingly, excised from the donor area; the strip is then broken down into its smallest functional units, or follicular units. Before single strip harvesting came to the fore in recent years, older, infinitely more wasteful methods were employed. The first of these was the circular, punch grafts of yore, which have little to recommend them save their simplicity (they are essentially biopsy punches), and the ease with which they were directly placed into correspondingly circular holes in the recipient area. Next, ingenious surgeons devised multi-bladed scalpels; three or more (sometimes many more) blades, attached to a handle, were oriented parallel to one another, and many thin, narrow, long strips could be excised with one pass of the scalpel. These strips could then be placed flat on their sides and sliced into small mini- and micro-grafts, with little or no concern for follicular unit integrity. This, however, was not the only drawback; transaction rates were generally rather high, and were even higher when more blades were used. So time was saved, but lots of valuable follicles were wasted.

         What we know as single strip harvesting overcomes many of these disadvantages. Using two passes with a single blade, or a single pass with a double-bladed knife, an elongated strip is excised. It is possible, with careful technique, to achieve transaction rates of less than 2% (this means that fewer than two FU’s per 100 are sliced in two). It is estimated that transaction rates as high as 30% occur with the use of multi-bladed scalpels. Let’s do the math. If the patient needs 1000 grafts, then an area containing 1300 grafts would need to be removed just to account for wastage and still produce 1000 intact FU’s. If 2000 grafts were needed, 600 would need to be wasted! This is of serious import when we deal with a limited, finite amount of donor hair.

         This leads us to a discussion of graft dissection. One of the reasons many surgeons have used multiple strip harvesting with multi-bladed scalpels, is that an intact, single strip presents a number of difficulties in dissection. It is too thick to place on its side or to shine light through (transilluminate) in order to visualize the individual FU’s. Therefore, thin, multiple strips lend themselves to rapid, albeit inefficient, slicing of grafts. We feel, however, that the degree of wastage is unacceptably high, both during the strip harvest, and during graft preparation.

         To avoid these problems, the techniques of stereo-microscopic “slivering” and dissection are utilized. As soon as the donor strip is harvested, the slivering process begins. This is extremely painstaking; the strip is divided into small “slivers”, each one FU wide. These are then laid flat on their sides, and, also under the microscope, the individual FU’s are carefully sliced out and trimmed of excess connective tissue and fat. During this process, the grafts are suspended in a physiologic saline solution and kept chilled; this insures their viability and health while they are “out of body”. They are separated into one, two, three and four hair FU’s, according to their natural occurrence, and then carefully placed into the recipient sites.

         We feel strongly that follicular unit transplantation is the state of the art in hair restoration surgery. Older techniques are easier and more lucrative for the surgeon, require a smaller operative team, and may be easier to “sell” with the false promise of higher density. Follicular unit transplantation, done with single strip harvesting and stereo-microscopic slivering and dissection, requires patience, a large team, and meticulous work by the surgeon and assistants. Despite these demanding criteria, we are committed to using and refining this technique; in one or two sessions, patients can achieve results that are natural, undetectable, and will stand the dual tests of time and of advancing baldness.

Harvested by Follicular Unit Extraction: State of the Art 2003 – Present.

         In 2003 a handful of physicians began practicing Follicular Unit Extraction (FUE) worldwide.  This was an offshoot of a procedure developed by Ray Woods, MBBS in Australia in the mid-1990s.  The leaders in the advancement of FUE were Alan Feller, MD, Roy Jones, MD, and John P. Cole, MD.  Drs. Bernstein and Rassman published the first paper on FUE in 2002, however, they did not advance the technology or promote the popularity of the procedure.  Rather, they continued to advocate for a completely useless FOX test to verify a patient’s candidacy for FUE long after the value of this test was proven invalid in 2003.  In 2004, Jim Harris published his work on the dull method of harvesting grafts for FUE.  Today, the majority of grafts are harvested by sharp dissection. 

         FUE offers many advantages over strip harvesting.  In FUE grafts are harvested individually by the physician.  This a eliminates the complication of a linear strip scar produced by strip harvesting.  This linear strip scar is unpredictable in diameter.  Linear strip harvesting produces follicle growth distortion. FUE produces no follicle growth distortion.  FUE allows for a greater number of potential hairstyle lengths because there is no unpredictable linear strip scar.  The linear strip harvest scar often requires a longer length of hair to conceal the linear strip scar.  Even with long hair a linear strip scar may be noticeable especially when the hair is wet.  FUE does not produce this potential complication.  Both FUE and Strip harvesting do reduce the density of hair and the total number of follicles in the donor area however.  FUE is the opposite of grafting a bald recipient area.  In grafting the bald recipient area, follicles or small groups of follicles are transferred one at a time.  In FUE, follicles or small groups of follicles are harvested one at a time.  The goal with maximal FUE is to create the potential for an even density of follicles in both the recipient area and the donor area. 

The Donor Area: Out of Sight, Out of Mind

         Having discussed follicular unit transplantation, hair density and characteristics, and some of the older techniques of hair restoration surgery, let’s now lend our full attention to the donor area. This is often minimally considered, by patients and by surgeons, as it is covered by hair, and seldom seen by the patient or, hopefully, by anyone else. It is, however, of utmost importance for achieving the highest level of cosmetic excellence; respecting and protecting the donor reserves is vital in planning for future hair loss and possible future procedures.

         Donor Area Location

         If you have ever seen a man with Class VII balding, and we all have, you have seen a graphic representation of the limits and confines of the donor area. This is the hair zone that is considered permanent. With rare exceptions, this rim of hair remains even in the most advanced cases of male pattern baldness. The boundaries of this zone extend from in front of the ears, around the temples, and to the back of the head (figure 1). The hair at the temples may recede back toward the ear, and the balding area of the crown may dip quite low into the occipital area, at the back of the head. We must always assume that any man considering hair transplant surgery will eventually advance to this Class VII level for balding; it’s easy to understand why. Visible scars may be revealed if the baldness advances, and donor tissue has been taken too high, too low, or too far in front of the ears.

         Scarring in the Donor Zone

         Another problem involving scarring in the donor area is that of the widened scar. In a patient without a systemic disease or drug use that retards healing, a well-closed, non-infected incision should eventually appear as a thin white line, well camouflaged by the hair. Sometimes, however, this is not the case. For example, if the donor strip is taken too low in the back of the head (toward the top if the neck), a widened scar can result. Often, as men get older, the inferior hairline (at the neck) will move higher. If this is the case, a low, widened, visible scar can be a cosmetic liability.

         In addition, certain patients with an inborn weakness of collagen or defects in the building of new collagen (collagen is the connective tissue protein of which ligaments, tendons and scars are made) may develop wider than normal scars regardless of how well the incision is closed. Surgical wisdom has always taught us that closure of any wound under tension (such as a wide incision or in taut tissues) can lead to a widened scar. Therefore, we always attempt to make the donor strip as narrow as we can, based on the tightness or laxity of the patient’s scalp. Indeed, this is one of the problems seen after scalp reductions and/or multiple transplant procedures: a tight, unyielding, fibrotic donor area. This is why hair restoration surgeons like to see patients with lax, loose scalps. Occasionally, though, a paradox exists. This is when patients who do have scalp laxity heal with widened scars. It is possible that these patients may have one of the aforementioned collagen defects. In short, careful evaluation and planning can result in fine, cosmetic scars in most cases; there are cases where the scar is sub-optimal regardless of the surgeon’s skill.

         Many of us today see the results of older methods of donor harvesting; often, patients with the older, “pluggy” look of the past seek transplantation to remove or disguise the old round grafts, or their balding may have progressed to the point that they desire grafting to newly bald areas. When the outmoded harvesting techniques of punch grafting with open donor healing were used, the result was a “shotgun” or “moth-eaten” appearance that is cosmetically quite displeasing. This type of scarring also renders further strip harvesting difficult, to say the least, and it greatly complicates the estimation of needed strip size for a given number of grafts. Similar problems arise when the patient’s donor area has been subjected to multiple small strip harvests, with a “stairstep” pattern of linear scars, or extensive plug harvesting that was then sutured in a “semi-sawtooth” pattern. 

         We have spoken in previous sections about the necessity of preserving the donor area for possible future transplant work. Even if an individual is older, has seemingly “stable” baldness, and is satisfied with his hair transplant outcome, the day may arise when his hair loss accelerates. Then, if his donor area has been conserved, he may have sufficient reserves for additional procedures. If not, then his options are limited to camouflage, hairpieces, or living with the appearance of baldness.

         We also discussed single strip harvesting as the technique with the most “hair-conserving” potential, and we deemed large sessions of follicular units as probably the most expedient and efficient method of transplantation. If these techniques are properly utilized, then the fewest hairs will be damaged at the time of harvesting. Furthermore, the integrity of the donor area will be preserved, scarring will be minimized, and preservation of donor reserves will be maximized for possible use in the future. This is an integral part of the essential long term planning process that will be discussed at length in a later section.

The All-Important Hairline: Our Facial Frame

            The Importance of the Hairline

         The frontal hairline is singularly the most important feature of the entire head of hair. It is the aspect of our hair/skin interface that we, and others, see first. When we look in a mirror, or walk into a room, when someone sees us and makes eye contact for the first time, the hairline stands out. On a subconscious level, beyond the rational, it speaks volumes about our age, attractiveness, suitability as a mate, even about our health and vitality.

         Why is the hairline of such significance? It frames the face. This simple statement belies the artistic and cosmetic impact of this all-important frontal zone. One of the reasons that many men with frontal balding instinctively go for the “comb-over” effect, is that it creates a hairline of sorts; it frames the face at the top and at the temples. The problem is that it is so patently obvious to everyone else as an attempt to disguise the balding.

         Framing of the face is an artistic metaphor. Imagine a painting without a frame. It may be a pleasing image, but it is incomplete. Add a nice, tasteful frame and voila! You have a complete, aesthetically appropriate presentation. Similarly, frontal hairline balding takes away the frame; restoring the hairline restores the frame. The resulting appearance is one of youth, vigor and vitality.

         Planning the Hairline

         Often, hairline planning is a compromise between the patient and the surgeon. This does not imply that the patient does not know what is best for him, or that the physician is wiser. What it does imply is that people have a tendency to want the hairline too high or too low. The low, rounded adolescent hairline will look inappropriate on a 40 year-old man. In fact, it may lend a caveman or “Neanderthal” appearance to his visage. Young men in their early twenties may require repeated explanation of the reasons for not creating an adolescent hairline for them. They still remember quite vividly (unlike the middle-aged man) their own, low hairline at the age of sixteen. Often, they are rather distraught about their loss of hair, and do not identify with their future selves at thirty, forty, or fifty. This is where the ethical hair restoration surgeon must explain and counsel for the patient’s benefit, rather than playing on fears and illusions in order to make a quick profit.

         Conversely, a middle-aged man seeking hair restoration surgery may fear that a hairline that is not adequately receded at the temples may seem unsuitable for his age. The fact of the matter is, that a hairline placed too high accentuates the balding, by focusing attention on the wide, high expanse of the forehead and frontal area. This concept may be easy enough to visualize if properly explained.

         At any rate, if one must err slightly to the extreme, it is always better to start slightly too high, than with a hairline that is too low. One can always, in a second session, bring the hairline down by artfully adding follicular units in front of the existing border. Still, it is much more desirable to get the hairline right on the first try. After all, the primary goal of almost all first hair transplant sessions is to re-establish the hairline and frontal region, in order to frame the face. This facial framework achieves the most dramatic cosmetic and visual effect of hair restoration surgery.

            Hairline Repair or Revision

         Repair or revision of the poorly done hairline is one of the most rewarding facets of the hair surgeon’s art, and often one of the most challenging. The border may be overly regular, with a symmetry that defies nature; conversely, it may by so disordered and asymmetrical as to be unnatural. Again, it may appear tufted, revealing the so-called doll’s hair effect. It might be too high, or more likely too low. Sometimes, the hairline is so overly rounded across the forehead as to be “bowl-like” in nature.

         All of these deficiencies can be corrected to some extent. The most difficult to correct is the low hairline. Even if the grafts are large ones, and can be cut out and dissected into follicular units (FU’s) for use elsewhere, scarring will result. This can be partially treated with dermabrasion and possibly lasers, but unless hair from further back can be styled forward to cover them, the scars will be detectable to some degree. We see here a graphic example of the necessity for good, rational, artistic planning when dealing with the hairline. Again, get it right the first time!

         The unnaturally straight or regular frontal border may be revised with the careful, selected placement of follicular grafts in front of, and among, the existing grafts; also, large grafts within and behind the hairline may be excised and re-used if necessary, with the hair around them acting as scar camouflage. “Softening” of the hairline is accomplished with the judicious use of single hair FU’s, in a more random pattern, which is harder than it sounds. Humans have a tendency when performing repetitive tasks, (such as making recipient incisions), to fall into a pattern of some regularity. It requires skill and effort to defeat this tendency and to achieve “randomness”; it’s not truly random, however, but more a “controlled disorder”.

         There are several possible remedies for an overly rounded hairline. One can blunt the fronto-temporal angles at the sides of the head to apply a more graceful curve to the margin. Alternately, a “widow’s peak” may be constructed at the middle of the forehead, which will soften and break up the arc of the frontal border.

         In the event the hairline has temporal recessions that are inordinately deep for the patient’s ethnic or racial background, then these concavities may be moderated by adding FU’s; this will render the margin “flatter”. Finally, a repair session can be exploited to increase the density of the frontal area, if adequate donor reserves exist. This technique can also be employed to fill in around mini-grafts that look “tufted”, or just to augment the density after an initial, successful follicular unit transplant.

         To reiterate, the frontal hairline is the most important area to be considered in most men with pattern baldness. Reestablishing the hairline has a great cosmetic impact, regardless of the degree of balding, and should generally be the goal of the first session of follicular unit transplantation. It must be remembered that reconstruction of the frontal area will have a profound aesthetic impact on the balding person, even if there is a limited store of donor hair.

The Crown: Important or Not?

         Location of the Crown

         The location of the crown is actually a point of controversy. The area at the back of the head is rather ill defined in the first place; some people refer to it as the crown, some as the vertex. Others refer to the vertex as the highest point on the head. For purposes of this discussion, we will call the crown the area behind the highest point on the head; in others words, the area behind which the horizontal plane of the top of the head abruptly changes to a sloping, more vertical plane. In many people, it is a rather flattened region roughly the size of the palm of the hand. Obviously, from looking at Class VI and VII balding, we can see that the crown has the potential of becoming even larger with extensive balding. In short, the boundaries are vague when there is abundant hair in place, but the crown may become the largest bald area on the head with extreme hair loss.

         Characteristics of the Crown

         In addition to its expansive size, there are other interesting aspects of the region we call the crown. Hair growth at the center of the crown is centrifugal; that is, the hair emerges from the scalp acutely and spirals in an outward direction. Sometimes there is a cowlick at the center of the spiral, which is more obvious in straight, coarse hair. Occasionally, there is a double spiral, which really makes things “interesting” for the hair transplant surgeon.

         The presence of this swirl makes more sense when we examine the direction of growth of hair in other parts of the scalp. In the back and sides of the head (occipital and parietal regions), hair growth is down and to the back. At the temples, the hair abruptly changes its orientation from forward to down, and then back. From the crown area forward, including the top of the head and frontal region, and frontal hairline, the direction of growth is forward. So we see the crown as the center of the growth swirl, or the “merging” of these differing hair angles. The logistical and cosmetic importance of this will become clear as the discussion continues.

         Hair Loss Patterns in the Crown

          The Crown is involved in many of the hair loss patterns that we see clinically, and not just the Norwood, or classically “male” patterns; it is also part of the Ludwig, or typically “female” forms of pattern baldness. The crown may be affected in any of the three degrees of Ludwig presentations. (Notice that women can sometimes develop a Norwood, and men a Ludwig, type of balding). That being said, let’s take a look at crown involvement in Norwood types of balding.

         Norwood Class IV though VII all entail loss in the crown, but with increasing magnitude; Class II and III do not. However, we have additional groupings, the II Vertex and III Vertex; these are the same as the II and III, but with a “bald spot” at the crown. Again, the more advanced IV, V, VI, and VII patterns all represent at least some crown loss. However, there are the “A” variants, II through V, which involve only the front and top of the head, excluding the crown. Finally, some patients present with no frontal loss at all, just exclusive crown loss (the isolated bald spot).

         Challenges in Crown Restoration

         Two essential groups of problems arise when dealing with crown balding. The artistic/aesthetic difficulties crop up when transplanting an area characterized by a swirling vortex of hair directions, often with thinner hair toward the middle. Also, this configuration amounts to a circular “part” which exposes the scalp, and any transplanted groups, to fairly close examination in social settings. Therefore, it is a technically challenging area in which to create appropriately placed and oriented recipient sites; and the correct size grafts must be placed in different regions of the crown.

         The other major difficulties are related to supply and demand. The potential size alone of the crown can create an insatiable demand for donor hair, which, as we have seen, is limited. Let’s consider the mathematics of this and other regions: the frontal area, from the hairline back to a line drawn across between the two temporal angles, measures an area of roughly 50 cm2. The top of the head, from behind the frontal area to the front border of the crown, may be about 150 cm2. The crown, as we pointed out can vary widely in size, but in a Class VI or VII patient can be as large as 175 cm2: a lot of area to cover! Doing the calculations, we see that, even if we transplant a minimal density (say, 15 FU’s or about 35 hairs per cm2) to a fully bald crown (about 175 cm2), we have used roughly 2600 follicular unit grafts. If we go for a higher density, for example, 40 FU, then we have used 7000 grafts, more than the average person even has available in their donor area. Again, this is in the crown alone. This leaves the cosmetically important frontal area and hairline with essentially no donor hair for transplantation.

While the above example is an extreme one, it is used as an example to show just how much of the donor reserves can be exhausted by the injudicious attempt to fully restore the crown with high density. In a young, desperate man with new onset crown balding, it may be tempting to try to fill this area in with dense packing of grafts; this, however, could be to his long-term detriment. If the balding in the crown continues to expand, the patient and surgeon can find themselves “chasing” the balding with ever increasing circles of grafts, like the layers of an onion. Not only can this quickly deplete the donor area, but if the hair characteristics and donor density are unfavorable, he may find himself with an “island” of dense crown hair sitting amidst an ocean of bald scalp. Moreover, what is he to do if frontal balding ensues? The man who was desperate about his crown balding at age 24, is bound to be absolutely frantic when his hairline starts to recede at 28; this will be even more noticeable than the hair loss at the crown.

Often, especially in younger men, it is appropriate to use medical management with Propecia and/or Rogaine, which tend to be more effective in the crown area than frontally. This may help at least maintain the hair in the region; surgical planning can be done to include hairline restoration, and transplantation to the frontal area as far back as the crown. This will be a more beneficial use of donor reserves from a cosmetic standpoint. The crown can then be transplanted carefully and judiciously, perhaps with a lower density, and the advancement of the patient’s hair loss can be observed over time. We must always be mindful that the large crown can drain the donor reserves, and that transplanted density is often best “spent” on the top, in the frontal area, and at the hairline.

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