Category: Hair Density

what is the most you pack per cm2 when you do a transplant????? please let me know .. thanks

Density of the average person is about 200 hairs per square mm. A doctor can transplant as high as 10-50% of the original density. It is important to focus more in the issues of fullness. This is not a ‘weight lifting contest’, which is unfortunately what some doctors are pushing for. I could transplant as much as 50% of the original density, but the real issues are:

1. Will it grow? There are many factors that will determine this: the health of the skin, the amount of atrophic changes in the skin caused by sun damage and the advanced level of balding, scarring that is present, etc. We generally expect that growth will approach 100% of what is transplanted, but that is only true when everything is right-on — and that rarely happens.
2. What is needed? This is the most important question that must be asked. People with low hair to skin color contrast, good texture, good hair thickness, etc. do not generally require the greatest densities to achieve the look of fullness.

Hair transplantation is as much an art as it is a surgical process. The judgments of a good surgeon with years of experience will make the correct decisions that are in the best interests of the patient.

i am a student at State University of New York College at Geneseo. i am doing a reseach and it requires me to find out the density of human hair, in terms of kg/m^3.

i know that human hair density might have a range. if you have that stat., please also give me.

thank you very much for your concern.

In the Caucasian, human hair density averages 2.2-2.3 hairs/mm square. In Asians, the density averages approximately 1.6 hairs/mm square and in Africans, is averages apprxomately 1.3 hairs/mm square. In the head of an average male with a hair bearing area of approximately 80 square inch area, the density is approximately 1250 hairs per square inch (rounded) bringing the total count to 100,000.

You must keep in mind that this is center point in a Bell Curve, and standard deviations overlap heavily between the races. The highest densities I have measured were in Caucasians at 4 hairs per mm square and the lowest numbers are not trustworthy because they may reflect diseases or some form of genetic balding.

How many hairs (grafts) does a person have to transplant?

I assume that you are talking about the donor hair supply. The supply is calculated by using the most bald person you can find. Assuming normal density of his hair, a person with the Norwood Class 7 hair loss pattern (the worst case) will lose 70% of the total hair he was born with. This will leave him with a 3 inch by 14 inch wreath of hair around the back and sides of his head. Assuming 100,000 original hairs averaging 2 hairs per follicular unit, that would mean that such a person could theoretically move half of the permanent wreath of hair (15,000 hairs or 7,500 grafts). There are other factors involved such as the looseness of the scalp and healing factors. We have a number of patients with Class 6 and 7 hair loss patterns than have moved between 15,000-20,000 hairs. The ones with the very high numbers generally had higher densities of the hairs on the head. One patient comes to mind had a birth hair population of about 150,000 hairs. He had 50% more to work with and he took advantage of that supply with wonderful results.

Generally, that is a lot of hair to move and unless you are very, very bald and have a very ‘perfectionist’ view of your need for fullnesss, most people get away with moving less hair.

I have followed your work for years, and believe me when the time comes, you are the one I will be going to. How come the crown continues to be so challenging? Most photos seem to show sparse coverage. I have taken proscar for several years, and my crown has filled in nicely. The front filled in a bit with rogaine but not at the density I would like. I am intrigued by the FOX and Mega sessions, but is the donor area so large that you gain hair in one area and lose it in the other? What happens in the large donor area?

Everyone is different. I try to imagine and plan for the worst case hair loss. Depending upon age and family history, I can often make a reasonable intellectual guess on what the worst case hair loss pattern will be. With Propecia, the worst case is usually ‘less’ worse. The crown is usually slower to bald for many people so Propecia works better because it is usually started before the crown goes bald enough to notice.

The size of the donor area is determined by the density of your donor hair, your scalp laxity and the size of the non-balding area. You are correct, that once you move most of the available donor hair, then there may not be enough hair available for future hair loss. If you have good scalp laxity and your density is high, then there could be enough hair to cover the entire head, even for the baldest of men. A good surgeon will make sure that the donor area is the appropriate size and take into consideration future balding and how the donor scar can be hidden by existing hair (if it should scar). I would have to see you to determine where you are in the balding process and where you might lose more hair. As you are in Los Angeles, a free visit to my office will help. We also hold monthly open houses, so you might want to come and see patients for yourself, watch a surgery and let us examine you all at the same time. In fact, our next open house even will be held next Thursday, July 7, at our LA office. Please see the NHI Events page for more details.