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Density Changes in CTE vs AGA over Time

Chronic Telogen Effluvium: How does density change over time?

Chronic Telogen Effluvium (CTE) and Androgenetic alopecia (AGA) are both commonly encountered diagnoses in women age 40-70 years. They are however, very different conditions. 

CTE-density

AGA: Androgenetic Alopecia

AGA presents with hair thinning and sometimes increased daily shedding as well. The loss of hair is sometimes just frontal in location or the crown but can be diffuse (all over). A key to the diagnosis is recognition of the progressive reduction in the caliber (diameter) of hairs. 

 

CTE: Chronic Telogen Efflvuium


Patients with CTE can appear to have a similar story. Many have a sudden onset of shedding. The shedding is diffuse. The temples may be particularly affected with reduced density to a much more significant degree than seen in AGA. Reduced hair caliber (miniaturization) is not a feature of CTE. CTE has periods where shedding appears to slow considerably or even stop. When one follows these conditions for many years there is a realization of another important difference: Density in CTE reduces initially but then plateaus and does not reduce further. Density in AGA continues to drop off over time. These points are illustrated in the graph.


Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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Scalp Elasticity: The Mayer Paul Formula

The flexibility or "elasticity" of the scalp is an important consideration for hair transplant surgeons performing follicular unit strip surgery (FUSS also called FUT). In general terms, the more elastic an individual's scalp is, the greater the number of grafts that can be taken ...  and the better the final hair density that can be created for the patient undergoing surgery.

 

A number of formulas and methods have been proposed to help surgeons calculate elasticity. There are even a number of commercial available instruments and tools that can also be bought to help calculate scalp elasticity.

 

The Mayer Paul Formula

The Mayer - Paul Formula is a well established method for calculating the elasticity of the scalp. To calculate elasticity on the scalp, two lines are initially drawn 5 cm (50 mm) apart. Then the two lines are compressed together (ideally with the two thumbs). Then, one records how far apart the two lines are after being squished together.

Scalp Elasticity is calculated as

[(50 mm - new position in mm)/50] multiplied by 100 %

 

VIDEO EXAMPLE: DEMONSTRATION FO THE MAYER PAUL

In this video example, the lines have been squeezed from 5 cm apart to 2.5 cm apart (X = 2.5 for the formula in this example). The elasticity is calculated as 50 %. According to the Mayer Paul formula elasticity of 30 % or more means that a strip of at least 2.2 cm can be taken (if needed) on a first FUT surgery. In contrast, 10 % elasticity means that the strip should be kept less that 1 cm in width


Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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How many hair transplants can a patient have?

Hair transplants: how many can a patient have?

The number of hair follicles available to move from the back of the scalp (the 'donor area') to the front or top of the scalp (the 'recipient area') is limited.  Someday, hair research may allow us to expand the number of hairs available, but for now there is a limited number. The number of grafts available to move depends on a number of factors, espeically how bald a person is destined to become.  It is generally estimated that between 4,000-10,000 follicular units are available in men. Men who are destined to have advanced balding patterns have less hair available to move than men destined to have minimal balding.

New study from Mount Sinai

A new research study by Dr Walter Unger and colleagues from the Department of Dermatology at Mount Sinai School of Medicine set out to refine these estimates even further. A group of 39 hair transplant surgeons were asked to estimate the number of 'permanent' follicular units available for surgery in a hypothetical 30 year old man destined to develop advanced balding (i.e. Hamilton Norwood Scale V or VI)

What were the results of the survey?

type VI 4000.png

Respondents indicated that men destined to have Hamilton Norwood Stage V balding had between 5,000 - 8,000 follicular units available for surgery and men destined to have Hamilton Norwood Stage VI balding had between 4,000 - 6,600 follicular units available for hair transplant surgery.Man with 4000 follicular units max in lifetime

Why are these results important?

This study reminds hair transplant surgeons (and patients) that there are a finite number of follicular units available for surgery. A middle aged man destined to have advanced balding in his  lifetime has two (and maybe three) surgeries maximum in their lifetime.   It is exteremely important to discuss with patients how grafts will be placed so that the appearance of bald areas of the scalp can be minimized throughout life.

Source

Unger WP, Unger RH, Wesley CK. Estimating the number of lifetime follicular units: A survey and comments of experienced hair tranpslant surgeons. Dermatol Surg 2013;


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Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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Hair Transplantation for Early Hair Thinning: Things to Think About

Hair Transplantation for Early Hair Thinning:

It comes as a surprise to some patients who come to see me that they are not candidates for hair transplant surgery. Some patients are too young, some have hair loss diseases for which a transplant won't ever 'work,' some have too little hair (or are destined to be too bald to make a transplant a good idea).  Finally, some individuals have too much hair.

It's this last issue that I'd like to discuss today - transplanting in areas of hair loss which are undergoing thinning but not yet significantly thin. Is it a good idea to transplant hairs in this area to prevent it from ever looking thin?

density crown.png

Is some cases the answer is yes, in other cases - no.  Even with the most delicate and meticulous surgery, exisiting hairs on the scalp can be damaged if the density is too high. There is a critical density below which a cosmetic improvement can be achieved.

Consider the young man (photo on the right) who came to see me for advice on getting a hair transplant. Is he a good candidate for hair transplant surgery? 

Not ideal.  A hair transplant in this man is unlikely to significantly improve density. This man would be much better off considering medical treatment with minoxidil and/or finasteride before considering hair restoration. Othe treatments could also be considered, including low light laser therapy. If these (and other) medical treatments didn't help, we could certainly discuss a hair transplant. 

At slightly reduced densities, it's possible to achieve a great cosmetic change. New hairs can be placed "between" the existing hairs in order to build a new density - without damaging any of the existing hairs.

Slide1.JPG

I'm a big believer in transplanting in the early stages of hair loss in order to prevent the appearance of hair loss. But there is a fine line between when this is a good idea, and when it's not likely to provide the patient any benefit.


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Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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To Dense Pack or Not to Dense Pack

What is dense packing?

fu densities.png

For patients having a hair transplant, dense packing refers to the placement of hair follicle grafts close together such that the final density is high (i.e. dense) - greater than 30-35 follicular units per square cm.  Dense packing may lead to densities as high as 50 follicular units per square cm in some cases. The diagram on the right illustrates these different densities.

Some surgeons have argued that dense packing is preferable in some cases because a better cosmetic result can be achieved. Other surgeons have argued that very good results can still be achieved wtih densities of 30 -35 FU/cm2 without risking the chance of getting poor survival of the grafts.   Poor survival is a theoretical possibility because grafts have to be trimmed thinner and thinner in order to be able to pack them close together.

Over the past 5-10 years, we have slowly gained more information about the survival of grafts and particularly how to improve the survival of densely packed grafts. But certainly more research needs to be done. A 2005 study showed that graft survival with dense packing at 50 FU/cm2 was 84 % (i.e. 16 % died) compared to 98 % (only 2 % died) at a density of 30 FU/cm2.   Compare this to a 2008 study by Drs Nakatsui, Wong and Groot which showed that survival was as high as 98.6 % in  a patient transplanted with a density of 72 FU per cm squared in on small test area. The technique used to tranpslant hairs in this study was slightly different than used in the 2005 study mentioned above.

To dense pack or not to dense pack?

The decision on packing density depends on many factors - including their age, the quality of their hair (i.e. hair color, curl, coarseness), the available donor hair and the likelihood of future balding.

Dense packing of 50 FU/cm2 in a 45 year old man with coarse curly salt and peppery colored hair probably won't give much of a cosmetically different result than a 30 FU/cm2 density. In fact, doing so runs the risk of using up more hair and possibly limiting the number of hairs that might be possible to transplant when the man is 55 or 65.

The decision on dense packing needs careful consideration. 

References 

Mayer M, Keen se S, Perez-Meza D. Graft Density Production Curve with Dense Packing. International Society of Hair Restoration Surgery Annual Meeting. Sydney Australia 2005

Nakatsui et al. Survival of Densely Packed Follicular Unit Grafts Using the Lateral Slit Technique. Dermatol Surger 2008; 34: 1016-25.

 


Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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The Normal Scalp

one two three hairs.jpg

When doctors first learn to examine the scalp, it’s not uncommon for many to be surprised about its complexities.   One of the joys of teaching is helping others understand not only what is "abnormal" - but also what is "normal."  Recognizing what is abnormal in the scalp can only occur with a thorough understanding of what constitutes a normal scalp examination.

One of the first surprises is the realization that hair fibers don’t emerge from the scalp one-by-one, but rather in groups. These groups of hairs are called “follicular units.” Some follicles have three or four hairs coming out, some have two and some have just a single hair. The photo at the right shows these follicular units labelled 1 (single hair follicular unit), 2 (two hair follicular unit) and 3 (three hair follicular unit). Sometimes hair fibers emerge from the scalp in groups of 8, 10 or even 15 hairs. A previous article discussed the diseases that can be associated with such a phenomenon.

PHOTO: Follicular units: Hair follicles emerge in groups of 1-5 hair

 


Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887
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