| Hair Orientation in Hair
Transplantation: an in-depth discussion by Dr. John Cole |
Dr. John
Cole
|
Reprinted with permission by Dr.
John Cole
www.forhair.com
There is little debate
today regarding natural hair groupings, but debate on hair orientation
persists. Some individuals have become proponents of the
so-called lateral slit technique and have adopted it. We
do not adhere to this dogma, but we recognize its potential benefits
over the vertical or parasagittal slit. We prefer to mimic
nature’s natural angles. These natural angles observed in a
typical patient are depicted below.
The
photograph above depicts the natural alignment of hair growth. The
white arrows depict the native direction and angle of growth. The
heavier white markers depict a line 90º to the angle of growth. The
red bar represents a line in the lateral or coronal plane; this is the
plane Dr. Hasson alleges to prefer because he feels it allows him to
create greater apparent density and a fuller look. We have found no
evidence to support this claim, and we are able to achieve equal
density and fullness using a hybrid technique. Furthermore, we find
that our technique replicates the aforementioned natural growth
patterns.. On the other hand, following a completely lateral pattern
of incisions will result in a relatively unnatural pattern of hair
growth.
The lateral incision, as such, was first adopted by Dr. Wong, but has
been popularized by his associate, Dr. Hasson. The assistants for Dr.
Limmer and Dr. Seager often use lateral incisions in their dense
packing sessions (some say it helps them achieve better density and
experience less popping). Again, I have not found that a more lateral
approach allows us to produce better density or greater ease of
placement, but I am open to these arguments. The lateral incision is
of significant importance to the field of hair restoration surgery
because it directs physicians to better understand the natural
geometry of hair growth. This understanding may make it easier to
achieve the appearance of fullness; some initial, though not
scientifically conclusive, studies suggest that the lateral incision
does create better “fullness” than the vertical incision. It may
be that a slight change in the lateral incision of 10 to 20 degrees
will result in even better density and the illusion of greater
fullness in accordance with nature’s original intent. Regardless, we
prefer a maximally natural result and therefore attempt to mimic
nature’s angles as much as possible.
One can see that the direction of hair growth enables coverage of the
area immediately in front of it and to its side. The hairs on the top
right side of the scalp are directed toward the left side of the
scalp; likewise, the hairs on the top left side of the scalp are
directed toward the right side of the scalp. The hairs on the left
lateral side of the scalp area are directed toward the left lateral
side of the scalp. The hairs on the right lateral side of the scalp
area directed toward the right lateral side of the scalp. Generally,
remnants of two geometric spirals (some inaccurately call them whirls
or whorls) are located in the temporal areas of the scalp. One is
located on the left and the other is located on the right temple.
These spirals may or may not be present and usually, when present, are
not entirely intact.. Sometimes a frontal spiral is noted in the
center of the hair line.
Many individuals have hairs that are angled toward the ear rather than
toward the nose along one side of the frontal hair line. This has been
termed a cowlick in the past by some doting mothers or hair stylists.
If a central or paracentral spiral is present, the person will exhibit
the aforementioned phenomenon. As previously stated, this usually
affects only one side of the scalp. It is must less common to see it
along both sides of the hairline, but this variant does occur. The
double cowlick results from two spirals moving in opposite directions
(one clockwise and the other counterclockwise).
It is important to note that spirals are either dominant or recessive
in nature, and that they manifest as either full or partial.. A
dominant spiral is fully visible, and has a defined point of origin.
It has the capacity to obliterate the recessive spiral’s pattern as
the two approach. The dominant spiral advances unimpaired through the
interface of the two spirals. The dominate spiral turns in the
opposite direction to its opposing recessive spiral. One moves in a
clockwise fashion, while the other moves in a counterclockwise
fashion. A recessive whorl takes a backseat to the dominant whorl and
may or may not be fully visible. Its center is typically found more
laterally on the scalp and usually is not visible. In other words, its
point of origin is not seen; therefore, you will find distal elements
of its geometric spiral and can only speculate as to its point of
origin.
The back, crown or vertex region all refer to the same area on the
scalp. This area always has a dominant spiral. Most commonly this
spiral is located lateral to the midline on the right side of the
scalp. This dominant spiral typically is clockwise in orientation and
its coverage extends anteriorly with hair directed from the left to
the right side of the scalp. The dominant spiral affects hair growth
angles along the medial aspect of the contralateral (opposite) side of
the frontal part of the scalp and all the hair growth angles up to the
frontal hair line on its ipsilateral (same) side of the frontal scalp.
Usually there is also a recessive spiral on every crown. It typically
is located lower than or inferior to the dominant spiral on the
contralateral aspect of the crown or the opposite side. Usually this
spiral does not have a point of origin that is visible and its hidden
origin is more lateral, as well as more inferior to the dominant
spiral. This recessive spiral usually moves in a counter-clockwise
rotation. This recessive spiral has elements along the lateral aspect
of the top of the scalp and affects hair growth angles along the left
side of the scalp. It typically affects hair growth angles along the
lateral margin of one side of the posterior donor region (usually the
left side). It does affect hair growth angles across the midline.
Occasionally, a recessive spiral is not seen and the dominant spiral
will hold sway across the entire posterior aspect of the donor region.
These individuals present the most difficultly with FIT, especially
when it occurs in the Negroid patient. Hair direction along the
frontal hair line may result from the dominant spiral, but more
commonly its direction arises from one of the three possible spirals
that form in the temple or the mid-frontal hair line region.
One should note that hairs do not direct themselves naturally in an
anterior or posterior direction. Rather they are directed in such a
way as to maximize coverage all over the scalp. They also tend to
augment one another as much as possible so that the coverage value of
each hair is maximized. In other words they tend to “shingle” over
one another in opposing directions so that the center of the scalp
receives the greatest degree of coverage. The directions of hair
growth in nature typically produce the highest degree of coverage
regardless of whether one parts the hair in the middle, the left side,
or the right side.
Victor Hasson claims that all hairs are directed in a line
perpendicular to our coronally depicted red line. This simply is not
so and in our opinion will result in less shingling and poorer
coverage than following nature’s own angles of hair growth. .A
person might have a full appearance when looked at head on, but they
would have a less full look when observed from the side. More
importantly, they will have a less natural result than if one followed
nature’s pattern.
It is very important to understand that Nature is efficient..
Typically, we find in our experience that following Nature’s
rationale results in a fuller, more natural cosmetic effect.
It is our belief that recipient site incisions should be perpendicular
to the large white lines so that the hair grows along the natural hair
growth angles which are depicted by the small white arrows. This will
result in the best degree of coverage and the most natural direction
of hair growth.
Hair
Angles in the Vertex
Here one can see the
complexity associated with the vertex. There exist three possible
spirals; a dominant spiral and two recessive spirals. The recessive
spiral on the left side of the patient is directed counterclockwise
although a clock wise spiral is also depicted on the left side. This
is not an accurate drawing, however. This spiral is actually directed
the opposite direction and gives rise the hair along the side of the
head and the left side of the donor region. A third recessive spiral
may give rise to the hair orientation in the back of the scalp toward
the midline. It simply is something we must begin to study much more
closely.
Growth
along the sides of the scalp
Growth along the sides of the scalp flows along similar spirals.
The right side of the scalp flows in a clockwise direction, while the
hairs along the left side of the scalp are aligned in a counter
clockwise fashion.
As you
can see from the above photograph the hairs follow a spiral
orientation whose source definitely includes the spiral on the left
side of the vertex. It may include components whose origin is another
recessive spiral located more laterally and anteriorly on the scalp.
The tightness of the spiral columns as you move more anteriorly
suggests this may be true. Also there is a rather abrupt change in the
orientation of the hair to a tighter curve. There is often a third,
more anterior spiral, which is located in the temple region. This
spiral is lost generally at puberty in most males. It tends to remain
much longer in females. It is also seen in some males of various
ancestries such as in descendants of the Mayan Indians.
Here you
can see the direction of hair growth in the back of the scalp is
derived from four different spirals. The dominant spiral in the vertex
controls the majority of hair growth direction in the back of the
scalp. As you can see the flow is predominately in a clockwise fashion
in the vertex with the hair angled in an opposite direction to the
flow of hair on the left side. The dominant spiral is depicted as it
characteristically controls the flow of hair across the midline. As
previously stated, the hair on the left side of the scalp is derived
from a recessive spiral and controls hair growth direction along the
lateral side of the posterior scalp over the mastoid region. I have
seen unusual patterns where the dominant spiral controlled hair growth
direction along the entire posterior aspect of the scalp. I find this
the one of the most difficult patterns of hair growth to extract using
FIT, but it is not impossible. Hair is directed along a three
dimensional plane on both sides (along the left side it is directed in
a positive X, positive Y, and negative Z axis, while on the right side
it is directed along a negative X, positive Y, and negative Z axis).
The neck region is comprised of two different spiral formations. These
are either unique spirals or continuations of the dominant and
recessive spirals that compose the more superior regions of the
posterior scalp. Sometimes the neck spirals act in a more dominant
fashion and alter the geometry of the posterior and inferior scalp by
causing the hair to move along a different axis, angling superiorly or
along a positive Z axis. This becomes the most challenging form of
hair growth for the FIT procedure, when the angles are quite acute and
the patient is an African American.
This
also shows the major problem associated with strip harvesting other
than its greater degree of tightness, its invasiveness, its greater
potential for pain, and it’s obvious production of a linear scar.
The strip harvest destroys the natural geometry of the scalp. You can
see how the spiral numbers are depicted on these pre-operative and
post-operative photographs. Strip harvesting eliminates the ability to
line up these spirals properly following strip harvesting. The spirals
are shifted and it is impossible to repair this distortion of the
natural geometry of the scalp after a single strip harvest is
performed. In other words, strip harvesting permanently deforms the
natural geometry of hair growth.
This
distortion of the geometry is depicted above following an actual strip
harvest. The angles of hair growth are parallel to the blue hypodermic
needles. In this instance, the donor region was temporarily stapled
closed and the needles were inserted parallel to the direction of hair
growth. You can see how the needles are angled along completely
different sections of the geometric spiral so that they exit in
completely different directions. It will be impossible to repair this
geometric distortion.
Here you
see a three dimensional depiction representing how hairs are aligned
in rows of spirals.
This
represents the triangular matrix of the follicular groups at an even
smaller level. The follicular groups are aligned in rows, but they are
located in offset spaces. These offset or staggered rows add to the
illusion of fullness and coverage with the fewest hairs possible to
achieve this illusion of fullness. The overall geometric patterns of
hair growth are an amazing architectural achievement which begins at
the smallest level, the single follicular group and is arranged in
ever more complex geometric fractals or patterns that are all
important to the appearance and degree of coverage possible. We firmly
believe that it is imperative to adhere to these natural patterns as
much as possible so that the most natural and fullest illusion of
coverage is achieved. This is why we are strong proponents of making
slits in the fashion of nature rather than in a purely coronal
fashion, and it is also why we are no longer aggressive proponents of
strip harvesting. Put simply, there are better options available.
