Bernstein Medical - Center for Hair Restoration - Hair Density

Hair Density

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RepliCel Life Sciences; a company out of Vancouver, Canada; is studying the use of hair cloning techniques to treat male pattern baldness and hair loss in women.

The study is in progress, but analysis of the 6-month interim results of the first phases has been published. The preliminary results at 6 months show that almost two-thirds of subjects (10 out of 16, or 63%) received a greater than 5% increase in hair density at the injection site. Of that group of 10 subjects, seven of them saw hair density improve by more than 10%. In one subject vellus hair density increased 24.9%, terminal hair density increased 14.5%, overall hair density increased by 19.2%, and cumulative thickness per area increased by 15.4%. There were no significant adverse safety events reported in the first 6 months of the trial.

Phase I/IIa of the RepliCel study involved injecting male and female subjects with their own (autologous) dermal sheath cup cells (DSCC), which were replicated or cloned using RepliCel’s laboratory technology. A preliminary analysis of the safety of the injections, as well as a preliminary analysis of the efficacy of the treatment in growing hair, was announced in May 2012 and presented to the European Hair Research Society in June 2012. Subjects in this part of the study will continue to be monitored for any adverse physical reactions and to assess hair growth at 12 months and 24 months after treatment.

Phase IIb of the study is designed to help the RepliCel researchers formulate the optimal treatment for hair growth. Some of the treatment regimens that will be tested include the use of different concentrations of cells and different treatment schedules, plus the effects of single injections versus repeat injections. The final protocols for Phase IIb are currently being worked out, with the clinical trial expected to begin in late 2012.

Reference:

Lortkipanidze, N. Safety and Efficacy Study of Human Autologous Hair Follicle Cells to Treat Androgenetic Alopecia. In Clinicaltrials.gov. Retrieved July 26, 2012, from http://clinicaltrials.gov/ct2/show/NCT01286649.

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Q: I was told that I have low hair density in the donor area. Will multiple hair transplant procedures improve the results of my hair restoration? — J.G., Hoboken, NJ

A: Yes, but subsequent procedures would be smaller and there is a point of diminishing returns where additional procedures would yield so little hair that they would not be practical. There is a finite donor supply and once this is tapped, no more hair transplants are possible, regardless if one uses FUT or FUE.

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Q: Can shock loss be eliminated by using special surgical techniques? — R.P., Short Hills, NJ

A: Although there have been no scientific studies proving this, shock hair loss can most likely be minimized by keeping the recipient sites parallel to the hair follicles, by not creating a transplanted density too great in areas of existing hair, and by using minimal epinephrine (adrenaline) in the anesthetic. We implement all of these techniques. Finasteride may also decrease shock hair loss, or at least help any (miniaturized) hair that is lost to re-grow. That said, some shock hair loss from a hair transplant is unavoidable regardless of the technique as it is a normal physiologic response to stress.

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Q: I am a 34 year old male and my dermatologist prescribed Propecia for me today. Most of my hair loss is at the hairline, but there is some loss on top as well. It’s not bad, I just want to stay ahead of it. If I get a transplant I want to get it at your clinic, but I will give the Propecia a try first. I am going to be overseas for a couple of months starting this Sunday and I was wondering about the necessity or desirability of having someone measure my hair density prior to starting the Propecia. Would you advise waiting to start the Propecia until I come back in two months and having my density examined at your clinic? — M.R., Great Falls, Virginia

A: I would start Propecia as soon as possible. What is important for a hair transplant is the density in the donor area and this is not affected by Propecia (or minoxidil). Your donor density can be measured anytime at an evaluation prior to surgery. If you want to wait to see the effects of Propecia prior to the hair transplant, you really should wait a year; since growth, if any, can take this long. If you just want to have Propecia on board for the hair restoration procedure, or to make sure you don’t have side effects, then generally a month will do. If you would like to do a photo consult through our website to get some preliminary information about how many grafts you might need, you can do that at your leisure, but start Propecia now since the longer you wait the less effective it will be at regrowing hair.

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Q: You mentioned that the hair at my crown and other areas where I now have baldness hasn’t really fallen off but has thinned to a great extent and that taking Rogaine and Propecia might help increase their thickness. If the medications do restore the hair thickness, I’m curious why you said that I could look like how I was 1 to 2 years ago. Technically, shouldn’t I be able to regain much more of my hair (and look like how I was longer than before that) since the follicles are all still there? — H.D., Park Slope, NY

A: Although Propecia is much more effective than Rogaine, even when used together, the medications are just not that effective in reversing the miniaturization process. They may bring you back to the way you were a few years ago, but will not restore your adolescent density.

Read more about hair density and miniaturization, Propecia, Rogaine, and other hair loss medication.

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Q: What color hair is the thickest? I thought it was brown, followed by red then blonde? But I am also reading that red is the thickest but redheads have the fewest hairs. –S.F., Cook, Illionis

A: In very general terms, the darker the hair, the thicker it is and the lower the density (hairs per area). For example, Asians have the darkest hair, the highest hair diameter and the lowest density. Scandinavian blonds have very high hair density and the fine (diameter) hair. But there are many exceptions, African Americans have black hair, but it is usually very fine and of low density. I have seen red heads in all categories.

For more relevant info on hair, visit our links on hair loss, hair anatomy, and the top myths about hair loss.

View before and after hair transplant photos organized by the patient’s hair density.

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Michael L. Beehner, M.D.
Saratoga Hair Transplant Center, Saratoga Springs, NY, USA.

SUMMARY of Dr. Beehner’s Abstract from his presentation at the International Society of Hair Restoration Surgery, 2005 – Sidney, Australia

There is a need to find the “threshold” density at which follicular unit (FU) graft recipient sites may be placed and yield excellent survival following a hair transplant. It also needs to be determined whether or not a smaller recipient site makes a difference in graft survival. This study looks at hair survival in two patients 18 months after they were each transplanted with four different densities.

The objective of the study was to determine the optimal density for “dense packing” FU grafts without causing loss of hair from vascular compromise or other factors that can affect graft growth during hair restoration surgery.

In the study, two male patients, both with Norwood Class VI patterns of hair loss, were examined. Two-hair FUs were planted respectively at densities of 20, 30, 40, and 50 FUs per cm2. 19g needles were used for the boxes with 20 and 30 grafts per box, and 20g needles were used for the boxes with 40 and 50 grafts/cm2. The grafts were placed using a “stick-and-place” method.

% Hair survival

Recipient Site Density 20/cm2 30/cm2 40/cm2 50/cm2
Patient I (18 Months) 95 93 70 67
Patient II (13 Months) 88 92 100 93

The author concluded that both patients had excellent growth of the transplanted hair at densities of 30/cm2. However, one patient had decreased density at 40/cm2 and 50/cm2. Based upon this very limited study, the researcher suggested that there are probably individual factors unique to each patient which affect graft survival of transplanted hairs at high densities.

The author proposes that the patient to patient variation at high densities may be due to variations in 1) scalp thickness, vasculature (atherosclerotic changes or differences in collateral circulation), presence of past transplant work or surgery with resultant “micro-scarring”, amount of epinephrine used in recipient area, or technique and care to grafts by cutters and placers.

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Follicular Unit Transplantation (FUT) was first introduced to the medical community by Dr. Robert Bernstein in his 1995 publication “Follicular Transplantation.” Dr. Bernstein presented this paper at the Annual Meeting of the International Society of Hair Restoration Surgeons the following year. However, the procedure initially met with great resistance by hair transplant community and for the next three years, only a handful of physicians were actually using this new technique. That all changed in 1998.

At the 6th Annual 1998 Meeting of the International Society of Hair Restoration Surgeons held in Washington, D.C., Dr. Walter Unger (defending the “old guard”) debated Dr. Bernstein (representing this new technique) in front of an audience of over 450 hair restoration surgeons from around the world. Dr. Unger took the position that large grafts still had a place in surgical hair restoration, particularly for creating density. Dr. Bernstein took the position that the new procedure of Follicular Unit Transplantation could create that density while at the same time achieving a completely natural look – something large graft procedures were incapable of doing. He argued that the versatility and naturalness of Follicular Unit Transplantation rendered the older procedures obsolete.

Follicular Unit Hair Transplantation clearly won the day… and the rest is history. Within three years of this debate, there were hardly any doctors left in the United States still performing large-graft hair transplant techniques. A review of their discourse appeared in Dermatology Times.


Excerpts from the debate with Drs. Unger and Bernstein taken from presentations at the annual meeting of the International Society of Hair Restoration Surgery held in Washington, D.C., 1998.

Is There Still a Place for Standard Grafts in Hair Restoration Surgery?

Position: YES

Dr. Walter Unger

You have to use the hair transplant technique that will give you consistently good results. I can consistently produce very natural-looking results regardless of the type of grafts that I use. I have many patients come back who report that even their hairstylists can’t tell that they have had transplants.

It’s not that I don’t like follicular units or have a thing about big grafts; I know that all of these techniques can yield good results. I object to the “absolute” rules presented by speakers at hair restoration meetings, on the Internet, or in advertisements in order to promote one particular concept.

Of course, you can produce 80 hairs per square centimeter with Follicular Unit Transplantation, and you get good results. However, you shouldn’t remove any of the other graft options, including standard grafts, from your armamentarium.

This is what is wrong with our profession right now: there is too much “irrational exuberance.” If you can find something that works well in your hands, then use it, but do not tell other people that it is the only way they can do things.

There are costs to follicular unit-only hair transplantation that must be recognized. I get less density with follicular units than I can get with a session using several different graft sizes. Given, thin is often appropriate; you don’t want to use up all of your donor hair frontally if you have a limited or poor donor-recipient area ratio. You also don’t want to use it up in a young man.

However, there are some people who can well afford the donor hair and want great density. In these individuals, mixed grafts are the best option in my hands.

Furthermore, there is more tissue handling with follicular unit transplantation during both preparation and insertion of the grafts. A larger number of grafts have to be transplanted, and they have to be densely packed if you want a dense enough result per session, compared with standard grafting.

Follicular unit grafting also risks the loss of hairless follicles. You can lose up to 13% of follicles that are in the resting telogen phase. Even if you can see these hairless follicles, and I’m not sure that you can, technicians are not looking for them when they are slicing up donor tissue into follicular units.

Admittedly, you have to be an extraordinary surgeon to get good results with large grafts at the hairline. However, when I use larger grafts, I use them in a limited area posterior to the hairline zone, which is always created with micrografts and minigrafts anteriorly as well as posteriorly; on either side of the larger grafts; and in areas of existing hair that is likely to be lost with the progression of male pattern baldness.

Position: NO

Dr. Robert M. Bernstein

Finally, after 40 years, standard grafts are on the defensive.

Standard grafts exhibit a callous indifference to human tissue. Standard grafting causes significant damage to the donor area through the larger recipient wounds. They always require a “cover-up” using smaller, more appropriately sized grafts.

Proponents of standard grafting claim that large grafts are needed for density and that large grafts avoid the loss of telogen follicles.

They also lament the psychological toll of long hair transplant sessions using small grafts but ignore the effects of a protracted course of small multiple surgeries.

These hair restoration surgeons attempt to impress you with fancy terms like “maximum density” and dazzle you with hair counts approaching 200 hairs per square centimeter.

But traditional grafts often cause the scalp to feel unnatural and have an unnatural look when wet, when the hair is seen at different angles, or when the hair is not perfectly groomed. Other dangers include decreased perfusion after healing, an unnecessarily large number of procedures, and long-term problems with hair distribution.

All of us can achieve high density, but the final density is determined by the amount of hair moved, rather than the size of the grafts. Density is a somewhat misleading term since a transplanted density that approximates 50% of the original hair density is indistinguishable from one’s original hair.

Regardless, you can achieve as much density as you want with follicular transplantation while maintaining a totally natural look.

Moreover, telogen hairs are not necessarily lost when properly dissected during follicular unit harvesting because they often are part of a follicular unit that has visible hairs.

The risk therefore of any of them being lost is negligible, particularly if the dissection is performed with care.

The future of hair transplantation lies in the ability to preserve the blood supply and minimize scarring in the recipient area.

When standard large grafts are used centrally, multiple hair transplant sessions are required and there is a possibility that the blood supply can be compromised, resulting in poor growth and “doughnuting,” a condition where the hair in the center of large grafts does not survive.

Hair survival in larger grafts is highly exaggerated; doughnuting and other evidence of poor graft survival are evident regardless of technique.

Large grafts are very inefficient, seldom grow at 100%, and require a “screening” population of micrografts and minigrafts to look natural. As a result, they rapidly deplete donor supply.

Regardless, the primary reason for the decline of standard graft use is that even the best of 4-session standard graft cases appear pluggy upon close inspection. The rationale for using standard round grafts has been to achieve maximum density. However, appropriate density can now be achieved with a hair restoration procedure that looks totally natural and avoids the problem of these larger grafts. If doctors had the insight to use small grafts when hair transplantation first began in the 1950’s would we even be discussing the use of the larger standard graft procedures today?

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