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| LASER
Hair Removal by using Medio shoer High Power Diode Laser |
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The
laser hair removal system a work using the principal of selective
photothermolysis, in which a carefully timed pulse of laser
energy passes through the skin and is absorbed and converted
to heat energy at the hair follicle. Because of 800nm wavelength
laser light penetrates deeper.
Laser Hair Removal works best in lighter skinned, darker haired
patients. Because the target chromophore in hair follicles
is melanin pigment, less laser energy is absorbed by the skin
and more by the hair follicle. Tanned skin also "robs"
laser energy as it passes through the skin to the hair follicle.
The Diode lasers are less dependent on skin color than the
ruby and alexandrite lasers. Because the pigment in the hair
is the target for the laser energy, gray or white hair (which
lacks pigment) cannot be effectively treated with any laser
or light-based device.
Multiple laser treatments are necessary for best results:
Laser energy has its greatest effect on growing, or anagen
hair follicles; as the dormant, or telogen hairs become active,
usually within 3 weeks to 3 months, some new hair growth will
be observed. Usually at least 3 treatments over the course
of a year will be necessary for satisfactory, long-lasting
results. The female face, armpits, and bikini lines are areas
which respond fastest to laser treatments- backs, arms and
legs usually need more treatments over time. The scalp is
very resistant to treatment.
Repeated laser treatments appear to induce a permanent reduction
in the amount of visible hair: Although current studies have
shown a "permanent" reduction in hair growth, some
hair regrowth may occur over time, although this is usually
much slower and much finer than before treatment. Imagine
a garden overgrown with weeds-after the first few weeding
sessions, only occasional "touch-ups" are needed.
True "permanent" "total" hair removal
may be possible with repeated treatments over time.
- The
area to be treated may be clipped or shaved, and a cooling
gel is applied. For small, curved areas, such as the chin,
a grid is marked out directly on the skin, and on larger,
flatter areas, such as the bikini line, chest, or back,
a transparent plastic guide grid is placed over the gel
to assure even treatment.
- Laser
pulses are then applied over the marked area. Discomfort
ranges from absent, in light-skinned individuals with coarse
hair, to mild stinging in patients with darker skin or more
hair follicles. An anesthetic cream can be used before treatments
in extremely sensitive patients.
- In
the weeks following treatment, hair shafts may extrude from
the damaged follicles, and may mimic the appearance of regrowth.
These may be left to fall out, or they may simply be plucked.
The area can be treated again when dormant follicles become
active, usually about a month on the face, and longer for
other body areas.
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Before |
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After |
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Hair does not have to be grown out,
and should not be plucked or few weaks before this removes
the hair shaft and decreases the effect of the laser. Please
inform us if you are taking any medications, using any prescription
creams or ointments such as Renova or Retin-A, or if you are
pregnant.
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| Forearms
("arms") |
Chest |
Abdomen |
Thighs |
Legs |
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Laser
Hair Removal Chart |
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| Back |
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Buttocks |
The
New Look Laser Clinic is using Medio Star High Power Diode
Laser Which is USFDA-approved safe and effective for Laser
Hair Reduction. Clinical trials have shown good reduction
in hair count after a single treatment, with complete destruction
of most actively growing hair follicles. Indications are that
this laser system may yield the most "permanent"
hair removal, in the sense that individual hairs are gone
forever. As with other laser hair removal systems, multiple
treatments are necessary, and gray or white hairs are resistant
to treatment. In our experience, we've seen no skin discoloration
or blistering, even in patients with very dark skin. Discomfort
during treatment depends on the thickness of hair in the areas
to be treated. Discomfort can be managed by decreasing the
fluence (which may make more treatments necessary), cooling
the skin with ice packs just before treatment, or applying
anesthetic cream when necessary. For extremely sensitive areas,
such as dense, coarse facial hair, local anaesthetic can be
used.
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| Male
pattern facial hair in a female, pre-treatment (left),
2 months after 3 Medio after Medio Star High Power Diode
Laser Treatments |
About Hair:
Hair is a dermal appendage found almost
everywhere on the human body except the palms, soles, and
lips. Vellus hairs are fine, colorless hairs ("peachfuzz")
covering most of the body, except those areas covered with
Terminal hairs, which are coarse pigmented hairs found on
the scalp and eyebrows. Vellus hairs can transform into terminal
hairs when stimulated by androgens (male sex hormones), especially
those on the face, back, chest, abdomen, axillae (armpits)
and genitalia at puberty. Vellus hairs can tranform into terminal
hairs with aging. The number of hair follicles present in
the skin is fixed at birth.
The hair shaft is composed of the protein keratin and is produced
in the lower part of the follicle, or bulb. The middle part
of the follicle contains the opening for a sebaceous gland,
the attachment of the arrector pilii muscle, and a thickened
area in the root sheath called the "bulge", which
is believed to contain stem cells important for regeneration
of the hair follicle. Melanin is produced in the bulb and
possibly in the bulge, and concentrated in the hair shaft
and upper part of the bulb. Depending on the thickness of
the skin, the bulb may be as deep as 7mm, below the skin in
the subcutaneous tissue. Actively growing, or anagen hair
follicles are longest and deepest, while follicles just coming
out of dormancy, the bulb is much more superficial (see hair
cycle, below)
Melanin is the pigment which gives both hair and skin its
color. Much more melanin is present in hair than in skin,
and this property allows relatively more absorption of laser
light energy in hair than in skin (see below). Hair color
is determined not only by the absolute amount of melanin,
but by the relative amounts of black-brown eumelanin and reddish
brown pheomelanin, and refraction of light within the layers
of the hair shaft itself.
Hair growth cycle: Hair
growth occurs in cycles throughout an individual's lifetime.
Active hair growth is called Anagen, and the length of the
anagen phase determines the length of the hair. Scalp hairs
may remain in the anagen for up to 3 years. Hair follicles
then enter Catagen, a phase of regression which lasts a few
weeks. The Telogen, or resting phase, can last for months,
depending inversely on the number of actively growing hairs
in the area, ie. the scalp has a shorter telogen phase than
the chest. As anagen resumes, the hair follicle lengthens,
the bulb descends deeper into the skin, and the old hair shaft
is gradually shed. In humans, individual hair follicles are
more or less independent, with most hairs in anagen at any
given time. In animals which shed their hair, the follicles
cycle more or less simultaneously.
| Body
Site |
%
Anagen (growing) hairs |
%Telogen
(resting) hairs |
Duration
of Telogen |
Follicle
Density |
Depth
of Follicle |
| Scalp |
85% |
15% |
3
months |
350/sq.cm |
5-7
mm |
|
Beard |
70% |
30% |
10
weeks |
500/sq.cm. |
2-4
mm |
|
Upper Lip |
65% |
35% |
6 weeks |
500/sq.cm. |
1-2.5 mm |
|
Axilla (armpit) |
30% |
70% |
3 months |
65/sq.cm. |
4-5mm |
| Chest/Back |
30% |
70% |
3 months |
70/sq.cm. |
2-5mm |
| Breasts |
30% |
70% |
4
months |
70/sq.cm. |
2-4mm |
|
Arms |
20% |
80% |
5 months |
80/sq.cm |
2-4mm |
|
Legs |
20% |
80% |
6
months |
60/sq.cm |
2-4.5
mm |
| Bikini/Pubic |
30% |
70% |
3
months |
70/sq.cm. |
4-5
mm |
Physical Basis for Laser Hair Removal: Laser Hair Removal
is based on the principle of selective photothermolysis, in
which energy is delivered to the treatment area in such a
manner as to maximize tissue damage to the hair follicle while
sparing the skin and surrounding tissue. Melanin pigment makes
a logical target chromophore, because it's most abundant in
the hair bulb, which is believed to be the most important
target for hair removal, much less abundant in epidermis,
even in dark-skinned patients, and it absorbs well in the
skin's "optical window" between 600-900nm.
Wavelengths under 600nm are strongly absorbed by hemoglobin
and protein (scatter), and wavelengths above 900nm are strongly
absorbed by water in tissue. Skin is relatively "transparent"
in the 600-900nm range, with melanin-bearing structures as
the most attractive target for laser energy.
Melanin absorption decreases with increasing wavelength. Ruby
laser light at 694nm is strongly absorbed by melanin, not
only in hair but in epidermis, so epidermal melanin content
limits the depth of penetration and energy fluence that can
be used without unacceptable thermal injury to the skin. Nd:YAG
laser light at 1064nm is much less strongly absorbed by melanin
as well as other chromophores present in skin, and therefore
penetrates much more deeply and with minimal epidermal reaction
and collateral heating. These properties can be exploited
clinically, as outlined below.
Diode
Laser: Solid state 800nm diode lasers feature a
longer wavelength and pulsewidth, theoretically offering an
advantage in treating darker skinned patients. The Aesculap-Meditec
MeDioStar has obtained the USFDA approved for Permananent
hair reduction.
Q-Switched Nd:YAG: With
a wavelength of 1064nm, relatively low melanin absorption,
and skin penetration up to 5mm, the Nd:YAG laser is an excellent
choice for laser hair removal, at least in theory. However,
the nanosecond-range pulse width of the Q-Switched YAG is
thousands of times too short to cause complete disruption
of the hair follicle, resulting in prompt hair regrowth. In
order to enhance absorption of energy, a suspension of carbon
particles can applied before treatment, usually after hair
removal by waxing, allowing the carbon suspension to penetrate
into the follicle and conduct absorbed laser energy to the
follicular structures, as in theThermolase SoftLight system.
Although safe for darker-skinned patients and effective for
short term hair reduction, the Q-Switched Nd:YAG is generally
considered the least effective laser for long-term hair reduction.
Photodynamic Therapy:
In photodynamic therapy a photosensitizing compound is applied
topically to hair-bearing skin after waxing, to allow the
compound to enter the now-empty hair follicle. The area is
then irradiated with laser light to activate the photosensitizer,
which releases toxic oxygen radicals that damage the hair
follicles. Currently in the investigational stage, preliminary
studies have demonstrated up to 40% hair loss at 6 months
after a single treatment. Photodynamic therapy has been used
with limited success for certain malignant tumors, but the
lack of safe, effective, selective photosensitizers have limited
its use.
Practical Aspects of Laser Hair Removal:
Preoperative evaluation: The most important consideration
with Laser Hair Removal is the patient's skin type and hair
color. The differential absorption of melanin in the hair
follicle and melanin in the epidermis determines the amount
of energy that can be safely used. The Ideal Patient has light
(type I) skin with black hair, and a patient with very dark
(type VI) skin with white or grey hair would have little if
any response. Presumably because of the absence of melanin,
no currently available device works well in patients with
canites, or grey hair.
| Skin
Type |
Skin Color |
Tanning
History |
| I |
very
fair, "transparent" |
Always burns, never tans |
| II |
fair |
Always
burns, tans with difficulty |
| III |
fair to light olive |
Burns mildly, tans slowly |
| IV |
olive
to brown |
Rarely burns, tans with ease |
| V |
dark
brown |
Very rarely burns, tans very easily |
| VI |
black |
Never burns, tans very easily |
An
underlying cause for the excess hair, if present, should be
corrected. These causes may include endocrine abnormalities
and medication effect, including minoxidil, steroids, oral
contraceptives, and some immunosuppressive agents.
Contraindications to Laser Hair Removal include patients who
have healed poorly after other types of laser treatments,
patients prone to skin discoloration, patients with grey or
white hair, and patients who are pregnant. There's no scientific
evidence to suggest that laser light used in hair removal
can injure a fetus, but the question of injury will not arise
should any fetal problems occur. Patients who are tanned should
wait for the tan to fade for best results, and patients using
photosensitizing medication such as Accutane, tetracycline,
or Retin-A should discontinue the medication weeks, and for
Accutane, months before treatment. Herpes Simplex Labialis
(fever blisters) can be activated by Laser Hair Removal, especially
on the upper lip, and patients with a tendency for fever blistering
can be started on antiviral medication before treatment.
Preoperative preparation: Hair
should not be plucked or waxed before treatment. This removes
the hair shaft from the follicle, thus removing most of the
melanin chromophore. Hair may be shaved, which preserves the
chromophore in the follicle, and prevent dispersion of energy
by external hair. Lotions, cosmetics, and other skin preparations
should be avoided on the day of treatment.
Postoperative care: In
most cases, little specific postoperative care is necessary.
Mild burning sensations and redness can be treated with ice
packs and oral pain medication. In cases where blistering
occurs, topical antibiotic cream and a non-adherent dressing
can be applied. Sun exposure should be avoided, and an SPF
15 or greater sunblock should be used. Moisturizing lotions
and makeup may be applied the next day. During the weeks after
treatment, damaged hair follicles and hair shafts are extruded
or shed, and may be misinterpreted as early regrowth of hair.
This is especially noticeable in areas with thick, coarse
hair.
Efficacy of Laser Hair Removal:
The "permanence" of Laser Hair Removal is often
called into question. In practice, no laser destroys all of
the hair follicles. Some follicles are destroyed, others are
miniaturized into vellus hairs, and some are shocked into
prolonged dormancy. Multiple treatments are needed for best
results, and the best interval for treatment is when new hair
regrowth is observed, usually 6 to 12 weeks after the first
treatment, and 3 to 6 months after the second treatment. In
most cases there will be visible improvement within a week
after the first treatment. Repeat treatments can be performed
at suitable intervals.
It's possible that with a sufficient number of treatments,
true "permanent hair removal" can be ultimately
achieved, but not for every single hair present in a given
area. As an example, only 30% of hair follicles on the back
are in anagen (active growth) at a given time-70% of the hair
follicles are in telogen (dormant), even though they may contain
visible hairs. Assuming a single laser treatment permanently
eliminates every actively growing follicle (the actual figure
may be closer to half), 70% of the hair follicles originally
present may eventually sprout visible hair. After 3 months
(the average length of dormancy on the back), 30% of the remaing
follicles will enter anagen, and if a second laser treatment
eliminates every actively growing follicle (30% of the 70%
remaining after the first treatment), then only an additional
21% of the original hair follicles will be destroyed, leaving
49% of the original hair follicles able to regrow visible
hair. A third treatment will leave 34% of the orginal follicles,
a fourth 24%, and so on. In actual practice, some of the follicles
are shocked into prolonged dormancy, or converted to vellus
hairs, so the visible effect is greater than suggested by
the percentages. Experience to date with laser hair reduction
suggests that the hair reduction achieved is "permanent".
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