A: The hair densitometer was introduced to hair restoration surgeons by Dr. Rassman in 1993. It is a small, portable, instrument that has a magnifying lens and an opening of 10mm2.

To use it, the doctor clips the hair short (~ 1-mm) and the instrument is then placed on the scalp. The doctor counts the total number of hairs in the field, looks at the number of hairs per follicular unit and assesses the diameter of the hair, looking in particular for abnormal levels of miniaturization (decreased hair shaft diameter caused by the effects of DHT).

The densitometer can increase the accuracy of the diagnosis of genetic hair loss by picking up early miniaturization.

It can also better assess a person’s donor hair supply, thus helping to determine which patients are candidates for a hair transplant.

Densitometry has helped us define the conditions of diffuse patterned and unpatterned hair loss (DPA and DUPA) and help to refine the diagnosis of hair loss in women.

A: If a person is to become a Norwood Class 6, the hair that we have available for us to transplant is only about 12% of what was there originally. This, of course, will vary from patient to patient depending upon one’s donor density and scalp laxity and a host of other factors.

We make the hair restoration look good by restoring 25-50% in the front, and proportionately less in the back. Logically one cannot restore 1/2 of ones original density to an entire bald scalp with only a thin strip of donor hair – there is just not enough hair, even with multiple sessions.

I transplant 25-35 FU/mm2 in one session, but this is the density created in the front, not overall.

Due to follicular unit graft sorting (placing the larger follicular units in the forelock area) this provides even more density than the actual numbers suggest. If someone is relatively certain to have more limited hair loss, then the numbers can be increased, but it is risky if you underestimate the degree of eventual hair loss.

Please carefully read the article on Hair Transplant Aesthetics.

It will answer your excellent question in greater detail. The article is a bit old, but the principles are the same.

A: Although the cosmetic benefit can be dramatic, a hair transplant only “moves” rather than creates new hair. In surgical hair restoration, a limited amount of hair from the donor area is transplanted to a much larger area in the front and top of the scalp, so that we can never reach the original density.

Achieving a cosmetically appropriate density in the front part of the scalp (which is around 1/3 to 1/2 of the original) generally takes two sessions and is the goal of most hair restoration surgery. Lower densities are used towards the back of the scalp.

A: Fine hair will give a thinner look than thicker hair, but will look completely natural. Thin hair doesn’t prevent one from having surgical hair restoration, providing your donor density and scalp laxity are adequate. These would need to be measured.