The term Follicular Units or FU´s is generally used when discussing surgical hair restoration, or Hair Transplantation. The term relates to hairs or the natural groupings of hairs found growing around the scalp.
FU´s are natural groups of hairs, the density of which differs depending on the area of the scalp; the sides having smaller FU groupings and the back the larger follicular unit groupings are found. The overall hair density is slightly lower around the sides of the head as is the actual number of hairs within each grouping, predominately 1 and 2 hairs per follicular unit; the back a higher % of 3 and 4 hair FU´s.
Follicular units are natural groups or bunches of hair and a vital component when creating a hair transplant; it is important the FU´s are kept intact as the various sizes need to be strategically distributed in the recipient area. When creating the hair line the smaller units are used, the initial hair line is solely made of 1 hair FU´s to ensure a soft hair line, with 2 hair FU´s behind to increase the hair density and fullness.
The larger groupings are used behind the hair line to add greater thickness across the frontal 1/3 and beyond; the FU´s are not placed randomly but strategically to create the illusion of the highest density possible. The highest density placed is always the frontal hair line due to only single hair units being placed; when multiply hair units are used the density placed can be lower due to more actual hairs within each FU. Care needs to be taken not to transect the FU´s when being extracted from the donor area.
FUE each FU is removed one by one from the donor using a small cylindrical punch tool that encompasses the group and punches around it; varying punch sizes can be used to encompass the various size follicular units. FUE is a blind technique in respect of extraction as it is impossible to determine the direction of the FU under the skin; great care is required when making the punch in terms of direction and depth of the FU.
FUT the donor can be “ballooned” to enlarge the area of the strip so under magnification it is easier to extract around the peripheral FU´s. The strip is removed and then divided under magnification into the natural groupings; cleaned and kept in a holding solution.
The number of hairs per FU averages out to 2.20 hairs, on small operations, hair line touch ups this will drop because of the higher % of single hair FU´s, but larger procedures averaging 2.2. When the hair is extracted from the donor area the groupings need to remain intact. FUT a strip is removed and on removal then divided under magnification into the natural groupings; cleaned and kept in a holding solution.
After the procedure you will be given the number of grafts placed in the recipient area; the graft count should be the FU count, but not the hair count, request the hair count per FU/graft also. Collate the graft/FU count as well as the hair count so the average number of hairs per FU can be calculated; an approximate average of 2.2 hairs per FU should be the result.