Hi Dr. Rassman, I appreciate you addressing this very important issue. However, I think you missed the questions on this post. It seems to me the poster is asking if there is really 10,000-15,000 grafts available for transplant in the average male rathar than how many can be transplanted in a single session. I have noticed an increasing number of doctors who are saying this and using it as a basis for giving young men very aggressive hairlines. Can you expound on the issue of how many grafts are typically available?
The available number of hair follicles for a hair transplant is different in each person. Some of the factors that affect the number of hair grafts are:
- Density of hair in donor area. Average density is 2.0 hairs per square millimeter. It could vary significantly from person to person and between different ethnic groups. The actual donor area may represent 30% of your original hair (the rim around the head) of which half are possibly harvestable (in theory). This would reflect about half of the 30% of the original or 15,000 hairs (reflecting about 8000 grafts).
- The size of the head also affects the size of donor area. Bigger heads with similar hair density have larger numbers of donor hair. Unfortunately, bigger heads have larger baldikng areas.
- The average number of hair in each follicular unit is also important. People with higher density will have less single hairs and more groups of three and four hairs. In those who may have densities of 3 hairs per mm2 (150,000 hairs on such a head) the harvestable hair will be higher and may run as high as 45,000 hairs or 22,000 grafts (theory of what can be harvested). Actually harvesting these high numbers is more the exception than the rule.
Considering all these above factors, you can calculate the possible number of grafts and add to it the effectiveness of those hairs in producing appearance of fullness. It is true that in an average man with an average sized head, with average hair density (2.0 per mm2), and an average number of hairs per each follicular unit (~2), you can remove about 10,000 grafts safely, but this number can vary significantly and other factors should be considered in this equation.
This number is driven from a simple calculation that needs to be done for every patient when planning a hair transplant. Obviously since there are a lot of variables involved, this number can vary significantly, but is still easily assessable.
You asked about using such numbers for justifying an aggressive hairline. I occasionally have to create a thinner hairline due to scarcity of donor hair considering all of the above factors. I strongly believe that normal placement of a hairline in the ‘mature position’ is the correct location for a hairline. The Master Plan I keep talking about determines the distribution of harvestable hair in a worst case scenario, so that no matter what happens to the patient, no matter how much hair loss occurs with age, the patient will ALWAYS look normal. The quality of the donor hair is also very crucial for making the decisions in the Master Plan. I will, once again, list the factors that make up the elements for calculating transplant grafts in a solid Master Plan:
- Hair thickness (the thicker the hair, the more volume it will produce, so less hair is needed for a given result).
- Hair curliness (the curlier hair generally appears fuller and less hair is needed to produce the same appearance).
- Contrast of the hair color and skin tone (the higher the contrast the more hair is needed to produce the appearance of fullness).
- Donor density and scalp laxity will determine the ‘number of grafts’ that are available at any one point in time.
As you see, decision making is complex and many factors are involved. So available hair follicles are only part of this and other factors, including hair quality, should be taken into account. I also have to mention the importance of patients having a real expectation and is involved in making decisions on how aggressive we should design the Master Plan. See Medical Publications on the NHI site for more.