Principles and uses of lasers in oral and maxillofacial surgery

PRINCIPLES AND USES OF
LASERS IN OMFS

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


• The term laser is an acronym for light
amplification by a stimulated emission of
radiation, which serves to explain most but not all
the critical physical interactions that occur within
a laser generating cavity.
• Surgeons do not necessarily have to be fully
tortured on the complex physics required to
create the various forms of laser radiant energy.
• However, it is pragmatic to have a general
knowledge of stimulated emission so that one can
evaluate newer laser technologies and
understand how lasers affect biologic tissue.

HISTORY
– The possibility of stimulated emission was
predicted by Einstein in 1917.
– Maiman in 1960 created the first operational laser
called Ruby laser and it was employed in treating
dermatological lesions.
– CO2 laser was fabricated by Patel and colleagues
in 1964.
– Lasers entered OMFS in 1970.

LASER PRODUCTION
Absorption: electron
absorbs energy and
transferred to more
exited state.
Spontaneous emission
of radiation: electron
returns to its resting
state and releases
electromagnetic
radiation in the form of
light.


• When an atom in exited
state becomes irradiated
with a photon of light of
same wavelength and
frequency that was
previously absorbed, as it
returns to its resting state,
it will emit 2 photons of
light energy of same
W.length traveling in the
same direction in spatial
and temporal phase.
• Because of this production
of electromagnetic energy it
is called
LASER ( light amplification by
the stimulated emission of
radiation)


PROPERTIES OF LASER LIGHT

1. Monochromaticity: with all of energy it produces
having same wave length.
2. Directionality : beam can travel considerable
distance with a minimal divergence(milliradans).
3. Coherence : is a distinct feature that allows laser
beam to remain parallel for long distance and
spatially coherent. This helps in extremely fine
focusing.
4. Brightness : high brightness- high energy.


PHOTOBIOLOGY

• Photobiologic effects:

1.Photocoagulation
2.Photovaporization
3.Photochemical
4.Photophysiological phenomena
All these are both wavelength and dose
dependent.

•
•
•
•

PHOTOCOAGULATION

Heating tissues above 60degree c.
Whitening of tissues
Changes in molecular structure of tissues
Collagen shrinkage in blood vessels causes
hemostasis .
• Laser damage to erythrocytes attracts a
population of platelets and causes
intraluminal thrombosis.

PHOTO VAPORIZATION

• Intense, highly focused laser radiation produces surface temp
exceeding 100 degree C, which causes tissue vaporization of
0.05mm thickness within 1/8 th of a second.
• Cellular expansion due to steam production
• Over 100deg C destroys cellular proteins
• Literally cell explode releasing the confined steam in the form
of plumes.
• When further heated results in complete or partial
combustion and produces smoke and flashes of
incandescence.


PHOTOCHEMICAL EFFECT &
PHOTOCHEMICAL THERAPY
• Here a Radiant energy possessing a multitude of
wavelengths is used to treat a host of dermatologic
diseases by administrating a Photosensitizing agent
to the patient before application of the light.
• PSORALENS (Tricyclic Furocoumarins) is used as a
Photosensitizing agent in combination with exposure
to UV radiations.
• Used in the treatment of Psoriasis,
Mycosis,Fungoides,Vitiligo, Eczema.


• Systemic administration of Photosensitizing
agent offers conveniance,bypasses the barrier
to radiant energy alone of the stratum
corneum, and may cause a uniform skin
concentration of Photoagent.
• Because the Photoagent is activated by optical
radiant energy, the effects of the
Photosensitizer are confined to exposed areas
and the penetrative action of the radiant
energy is limited to the skin


PHOTODYNAMIC THERAPY (PDT) WITH LAZER
• PDT using the laser is similar to the use of
photosensitizers and radiant energy, possessing less
power and in most cases shorter wavelengths.
• Initially PDT used Hematoporphyrin derivative and
red light to treat malignant diseases in humans.
• PDT therapy requires adequate tissue levels of
photosensitizer, oxygen and laser energy.


• The foundation of PDT is the activation of a
local or systemically administered
photosensitizing agent by radiant energy.
• PDT turns on the ability of certain chemicals
to accumulate in malignant tissues and to be
rendered cellucidal if activated, by exposure
to laser energy in the form of low intensity
visible or near infrared light.
• A range of oral microorganisms responsible
for both dental caries and PDL disease are
susceptible to the cellucidal effects of PDT.

PHOTOMECHANICAL EFFECT
(PHOTODISRUPTION)
• Photodisruption is not a laser application
sought by OMFS as a way of managing
diseased tissues.
• Most commonly used by Ophthalmologists.


TYPES OF LASERS
1. CARBON DIOXIDE LASERS
2. NEODYMIUM:YATRIUM-ALUMINIUMGRANETT
3. ARGON LASER
4. HOLMIUM:YTRIUM-ALUMINIUM-GRANETT
5. ERBIUM:YTRIUM-ALUMINIUM-GRANETT
6. POTASSIUM TITANYL PHOSPHATE (KTP)

LASER

DELIVERY

MODES

W.L
In nm

CHROMOPHORE

1

CO2

Articulated arm,
fibroptic

CW, P, UP,
Flash scan

10,600

Water

2

Argon

Fibroptic

CW, P

488-514 Hemoglobin

3

Nd:YAG

Fibroptic

CW, P
Q-Switched

1064

Hb, melanin

4

HOL: YAG

Fibroptic

P

2150

Synovium

5

KTP

Fibroptic

P

532

Hb, melanin, tatoo
pigments


LASER

DELIVERY MODES W.L
In nm

CHROMOPHORE

6

Er:YAG

Fibroptic

P, UP

2940

Water

7

Q-switched
ruby

Articulated
arm

P

694

Melanin, carbon tatoos

8

Pulsed dye

Fibroptic

P

4001000

Hb, tatoos,
vascular malformations

9

Copper vapor

Fibroptic

P

578

Hemangiomas
Tatoos
Vascular malformations

157-355

Cornea

10 Excimer

Flexible arm P


•
•
•
•

Continous
Pulsed mode
Superpulsed
Ultrapulsed

• Free beam
• Focused
• Contact lasers
• Non contact lasers


HOW TO USE A LASER
• Wide variety of procedures by laser can be
categorised into:
1.Incisional / Excisional techniques
2.Vaporization/ Ablation
3.Hemostasis/ Coagulation


Incisional & Excisional

• Co2 laser is used as a light scalpel and is operated in
focused mode (smallest possible spot size of that
laser).
• Focused mode – High power per unit- Deep cut.
• Planned margin should be atleast 0.5mm beyond
margins, failure to do this may cause thermal effect
to encroach on the lesion and make pathologic
interpretation unreliable. Area should be outlined

in a slow to moderate intermittent mode.
• Cutting in intermittent mode could result in
perforation rather than incising.

Incision should be performed in one or two passes
at a rapid rate of motion, slowing the laser motion
will result in deeper incisions but also lateral
thermal damage.
Deeper incisions are best achieved by increasing
power or performing additional passes rather than
slowing the traverse speed which may cause
widening the zone.


Care should be
taken to ensure that
the spot size
remains constant
during the
procedure to
achieve the uniform
depth incision.
Typical parameters:
spot size -0.10.5mm, power
setting within 4-10
watts

• Suture closure of areas excised with co2 laser
is not mandatory.
• Excellent hemostasis and less scarring,often
allows laser wound to heal secondarily.
• Laser wounds are slow to epitheliase.
Fibrinous coagulum acts as biological dressing
• If sutures are used, it is advisable to leave
them in place somewhat longer, than would
be the case with scalpel wound.

VAPOURISATION TECHNIQUE

• Useful in the management of surface lesions such as
hyper keratosis, epithelial dysplasia, lichenplanus etc…
• This technique is used in diffused mode where the spot
size is increased, and power density and depth of cut is
decreased.
• After it is outlined the lesion should vaporise in a
continuous series of connecting and paralleling “U” s,
this method ensures an even lacing of the entire
lesion.
• After initial pass is performed the surface
carbonization should be gently wiped with moist gauze


HEMOSTATIC TECHNIQUE

• There are number of laser that are highly
absorbed by hemoglobin, therefore an ideal in
management of vascular lesions.
• Argon, copper vapor, Potassium titanyl
phosphate(KTP), Nd: YAG, Co2 laser.
• Dry field should be maintained, other wise
water content greater than that present
intracellularly will absorb the laser energy
and negate its effects.


GENERAL PRINCIPLES OF CLINICAL
LASER APPLICATION
•

Careful observation of target tissue

•

Beam should be directed perpendicular to the
target tissue unless dissection of the underlying
tissue is desired.

•

When using the continuous or rapid mode the
surgeon should work expenditiously and with even
strokes.

•

Both the power density and fluence may change
with small variations in operative technique and
may affect clinical outcome in sensitive areas like
facial skin. Be aware of tissue that is in the path of
laser beam beyond the target tissue.

•

Width of laser cut corresponds to beam diameter,
the depth depends on power set and degree of
coagulation necrosis on duration of laser
exposure.

•

Heat produced sterilizes the operating field, so no
transplantation of pathology occurs even in touch
technique or with a free beam laser.

RATIONAL BASIS FOR USE OF LASERS

• CO2 laser, absorption is proportional to water content.
Therefore, tissues with high aqueous content like epithelium,
connective tissues or muscles rapidly absorb the incident beam.

• Non aqueous tissues like bone, tendon, fat are poor absorbers and
produces more heat and makes these tissues more anhydrous .
flaming may occur on prolonged application.
Ho:YAG lasers can be used here as they have shorter wave length
(less heat production).
• Argon has affinity for red pigment of hemoglobin and used in
photocoagulation of vascular lesions.
• Nd: YAG has affinity for dark pigments like melanin and protein and
is most useful for ablation of large volume of tissues particularly
when strict hemostasis is desired.


SOME OF THE COMMON CILNICAL APPLICATIONS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

Incisional and excisional biopsies.
Focal hyperkeratosis
Nicotinic stomatitis
Solar chelitis
Leukoplakia
Erythroplakia
Fordysces granules
Verrucos carcinoma
Oral papillomatosis
Lichenplanus
Oral melanotic macules .
Oral submucosa fibrosis

MANAGEMENT BY ANATOMIC REGION
•
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

TONGUE:
Fibroma
Papilloma
Granular cell tumor
Lingual thyroid
Hemangioma
Lymphangioma
Lingual tonsil
Lipoma
Pyogenic granuloma
Apthous ulcer


FIBROEPITHELIAL POLYP ON DORSAL SURFACE
OF TONGUE.

•
1.
2.
3.
4.
5.
6.

LIPS:
Mucocele
Pyogenic granuloma
Fibroma
Actinic cheilitis
Hemangioma
Apthous .


•
1.
2.
3.
4.
5.
6.
7.

BUCCAL MUCOSA:
Hyperkeratosis/dysplasia
Fibroma
Payogenic granuloma
Hemangioma/lymphangioma
Salivarygland tumors
Scar tissues/ hyperplastic tissues
Lichen planus.


•
1.
2.
3.
4.
5.
6.
7.

FLOOR OF THE
MOUTH:
Ranula
Salivary gland tumors
Sailolithiasis
Hemangioma
Lymphangioma
Leukoplakia/dysplasia
Ankyloglossia


GINGIVA:
1.
2.
3.
4.
5.
6.

Lichenplanus
Pyogenic granuloma
Fibroma
Papilloma
Drug induced gingival hyperplasia
Hyperplastic gingival tissue


•
1.
2.
3.
4.
•
1.
2.
3.
4.
5.

SOFT PALATE:
Salivary gland tumors
Hemangiomas/ lymphangiomas
Mucous retention phenomena
Palatal/uvular hypertrophy.
HARD PALATE:
Salivary gland tumors without bony invasion
Papillary hyperplasia
Pyogenic granuloma
Apthous
Gingival hyperplasia


•
1.
2.
3.
4.
5.
6.
7.
8.
9.

DERMATOLOGICAL USES:
Angiofibroma
Psoriasis
Neurofibroma
Erythroplasia
Pyogenic granuloma
Keloids
Tattoo
Scar revision
Basal cell carcinoma


LASER USE IN ANATOMICALLY DIFFICULT AREAS
•

1.
2.
3.
4.

Surgery in and around oral cavity and face is
complicated by the proximity to number of vital
structures.
Salivary glands and their ducts.
Nerves, blood vessels
Near the Commissures of oral cavity
Airway.


LASERS-TMJ
1.
2.
3.
4.

Anterior disk displacement
Synovectomy
Hypermobility
Perforated disk


•

LASERS IN MALIGNANT LESIONS OF
HEAD AND NECK

•

Ability of lasers to seal blood vessels, lymphatics, nerve
endings, decreased levels of inflammatory mediators and
reduced scarring, aids in surgery with limited complications.
Carbondioxide & Nd:YAG

1.
2.
3.
4.
5.
6.

Premalignant/displastic lesions
Carcinoma of tongue
Carcinoma of lip
Lesions of tonsils & oropharynx
Lesions of the palate
Verrucous carcinoma


VASCULAR & PIGMENTED LESIONS
Argon laser
Nd-Yag laser
Pulsed dye lasers
Q-switched Nd-Yag lasers
Examples
Hemangioma
Port wine stains
Neves


UVELOPLASTY


HEALING OF LASER WOUNDS


• Both clinical and laboratory studies demonstrated the CO2
laser produces wounds that heal differently from those made
by a scalpel.
• Scalpel wounds contracted significantly and developed rolled
margins that remained present 42 days later.
• Laser wounds also developed rolled margins , but flattening
occurred 28 days after lasing.
• Histologically, there are fewer mayofibroblasts present, which
appears to be responsible for less scar contraction.
• In addition, less collagen formation is noted, and epithelial
regeneration is delayed.


• The regeneration from the epithelial margins
appears to extend over the fibrinous coagulum
rather than proliferating beneath the granulation
tissue, as when wounds heal by secondary intention.
• Reepithelialization appears to be complete in 6
weeks, with the original wound outline visible.
• There is minimal scaring, and the overlying surface
remains palpably soft.


• Ductal orifices in the lased field do not demonstrate
any stenosis on healing.
• Laser wounds are thought to produce less post opp
pain.
• Vaporization of cellular structure, organelles, and
cellular chemical mediators, as well as sealing of
nerve endings, is considered responsible.


LASER IN WOUND HEALING
• Lasers employing low level radiant energy have
been claimed to produce a positive effect on the
biologic and biochemical processes of wound
reconstitution.
• Low level radiant energy of lasers have accelerated
wound healing, reduced pain and enhanced neural
regeneration.
• It also brings about more rapid epithelialization,
enhances neo vascularisation .


• Role of lasers in 3rd molar surgery reveals
although helium-neon laser produced a
significant reduction of Trismus, but there is
no evidence of it reducing pain.
• All the studies of laser wound healing have
focused on proliferative phase of wound
healing( the period of 10-14 days after wound
healing that is characterised by population of
proliferating fibroblasts and the initiation of
the synthesis of collagen).

COMPLICATIONS
• General complications:
1.Post operative infections
2.Contact dermatitis
3.Post operative pain
4.ocular injuries
5.Air way
6.Injuries to staff

• Complications unique to extra oral laser
surgery of head and neck:
1.Hyperpigmentation
2.Hypopigmentation
3.Erythema
4.Hypertrophic scarring
5.Milia and acne outbreaks


• Complications unique to intra oral laser
procedures:
1.Damage to dentition
2.Damage to oropharyngral tissues.


SAFETY MEASURES
• Shielding devices
• Fire hazards : drapes
alcohol in surgical field
• Specular reflection
• Electric shock
• Explosive hazards: ether
cyclopropane
alcohol
• Virus particles
• Combustion products are carcinogenic
• Anesthetic : endotrachial tubes
anesthetic gas mixture


Impacted teeth


freenectomy


GINGIVAL HYPERPLASIA


References :
• Laser applications in OMFS- Guy A. Catone
• Lasers in OMFS-Clinics of North America
VOL 16. NO 2. MAY 2004
• Lasers in OMFS and dentistry- Lewis Clayman
• Fonseca vol 1.


Thank you


Principles and uses of lasers in oral and maxillofacial surgery

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