Lasers in Oral & Lasers in Oral & Maxillofacial Surgery Maxillofacial Surgery
Lasers in Oral & Maxillofacial Lasers in Oral & Maxillofacial SurgerySurgery
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Contents
• Historical background
• Laser physics
• Photobiology of Lasers
• Laser safety
• Types of Lasers
• Clinical Applications
• Medico legal considerations in Laser Surgery
• Future Trends
•Albert Einstein – 1917 – Quantum theory
•Theodore Maiman – 1960 – 1st Laser using Ruby crystal
•Javan – 1961 – HeNe Continuous mode of laser
•Johnson – 1961 – Nd:YAG Laser
•Leon Goldman – 1963 – Father of modern lasers
•Patel – 1964 – CO2 Laser
•Anderson RR & – 1983 – Selective Photothermolysis
Parrish JA
Historical background
Laser physics
ELECTROMAGNETIC SPECTRUM
1020 1019 1018 1017 1016 1015 1014 1013 1012 1011 1010 109 108 107 106 105 104 103 102 101 100
ULTRAVIOLET VISIBLE LIGHT INFRARED
Frequency
Wave length 3AO 3nm 3µm 3mm 3cm 3m 3km
TV & RADIO WAVES
MICROWAVES
GAMMA WAVES
X - RAYS
IONISING NON - IONISING
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Generation of Laser Energy
Certain laser medium or LASANT with in the resonator
space is energized by internal or external energy to
produce an excited population of atoms, molecules and
rare gases (SPECIES). The energy with in the resonator
reaches a population inversion in which the greatest
cohort of species is in an excited state and in which
photons are emitted and amplified within a laser cavity.
The radiant energy is released as a laser beam.
The basic requirements for the laser activity are
– Active medium – LASANT
– Energy input – external or internal
– A population inversion through quantum
electronics
– Some form of optical feedback or optical
resonator
Laser Cavity
Fundamental components of laser system include
• Resonator cavity housing active medium• Energy input – external or internal.
The cavity is bound by two mirrors• One totally reflecting• Other partially reflecting
• The mirrors are essentially parallel to each other and placed at the either end of the cylinder
• The mirrors are separated by a fixed distance (d) forming a Fabry-Perot interferometer.
• Principle of interference. Two or more waves simultaneously penetrate some material, forms a combied wave. Resulting a larger wave.
» Constructive interference » Destructive interference
OUTPUT MODESOUTPUT MODES
OUTPUT MODESOUTPUT MODES
OUTPUT MODESOUTPUT MODES
TISSUE EFFECTSTISSUE EFFECTSTemperatureTemperature Visual ChangeVisual Change Biological changesBiological changes
37-6037-60˚C˚C No changeNo change Warming, weldingWarming, welding
60-65 60-65 ˚C˚C BlanchingBlanching CoagulationCoagulation
65-90 65-90 ˚C˚C White/grayWhite/gray Protein Protein denaturization, denaturization, necrosisnecrosis
90-100 90-100 ˚C˚C PuckeringPuckering DryingDrying
100-150 100-150 ˚C˚C PlumePlume VaporizationVaporization
150-210 150-210 ˚C˚C CarbonizationCarbonization Potential ScarPotential Scar
PATTERNSPATTERNS
DOSIMETRYDOSIMETRY
1. ENERGY
2. POWER
3. POWER DENSITY
4. FLUENCE
5. SPOT SIZE
6. PULSE ENEGEY
7. THERMAL RELAXATION TIME
COMPLICATIONSCOMPLICATIONS
1.Herpes Simplex
2.Dyschromias
3.Scarring
4.Eye and Teeth Injuries
LASER SAFETY
ReflectionReflection
ElectricalElectrical
PollutionPollution
FireFire
ShutdownShutdown
OCULAR PROTECTIONOCULAR PROTECTION
OCULAR PROTECTIONOCULAR PROTECTION
COMMONLY USED LASERSCOMMONLY USED LASERSTYPETYPE USEUSE
1) Erbium:YAG (pulsed)(2490 nm)
Ablative skin resurfacing, epidermal lesions
2) Nd: YAG, frequency-doubled (532 nm)
Pigmented Lesions, red/orange/yellow tattoos
Nd : YAG (1064 nm)QS
Normal mode
Pigmented lesions, blue/black tattoosHair removal, leg veins, non-ablative dermal remodelling
Nd: YAG, long- pulsed(1320 nm)
Non-ablative dermal remodelling
3) Alexandrite (755 nm)
QS
Normal mode
Pigmented lesions, blue/black/green tattoosHair removal, leg veins
4) Pulsed dye (510 nm)
(585-595 nm)
Pigmented lesions
Vascular lesions, hypertrophic/keloid scars, striae, verrucae, nonablative dermal remodelling
First LaserFirst Laser
PRESENT LASERSPRESENT LASERS
PRESENT LASERSPRESENT LASERS
HAND PIECEHAND PIECE
HAND PIECEHAND PIECE
RECENT ADVANCESRECENT ADVANCES1. Improvements & Combinations
2. Laser Phototherapy : Vitiligo:examiner laser : 308 nm
3. Non – ablative lasers
Nd :YAG (1320 nm)
Diode (1450 nm)
Er-glass laser (experimental)
4. Optical imaging
a) Confocal Scanning Laser Microscope - Diagnosis & Marginal Clearance without biopsy
b) Optical Coherence Tomography - Skin Tumours and Bullous disease
CLINICAL CLINICAL APPLICATIONSAPPLICATIONS
FACIAL SKIN RESURFACING
Indications:
1. Photo damage: Dyschromias & Rhytides
2. Atrophic (depressed) scars : Post acne
Chromophore : water
Mechanism : Thermal ablation of Epidermis & papillary dermis
Post op Care
Lasers
a) Single pass CO2
b) Modulated Er : YAG
TECHNIQUE
PHOTO DAMAGEPHOTO DAMAGE
DEPRESSED SCARSDEPRESSED SCARS
VASCULAR LESIONSVASCULAR LESIONSChromophore – OxyhaemoglobinChromophore – Oxyhaemoglobin
Absorption wavelengths – 418, 542, 577 nmAbsorption wavelengths – 418, 542, 577 nm
Laser of Choice : FPPDL – wavelength – 585, Laser of Choice : FPPDL – wavelength – 585, 590, 595, 680 nm590, 595, 680 nm
Cooling SystemCooling System
FiltersFilters
Fluence –5-14 J/cmFluence –5-14 J/cm22
Spot Size – 2-10 mmSpot Size – 2-10 mm
Density – Less than 10%Density – Less than 10%
Pulse Duration : 1.5-40 millisecondsPulse Duration : 1.5-40 milliseconds
Delay between pulses – 10-500 millisecondsDelay between pulses – 10-500 milliseconds
PORTWINE HAEMANGIOMAPORTWINE HAEMANGIOMA
Nasal TelangiectasiasNasal Telangiectasias
HYPERTROPHIC SCARS, KELOIDS HYPERTROPHIC SCARS, KELOIDS & STRIAE DISTANSAE& STRIAE DISTANSAE
FPPDL (585nm) – Laser of FPPDL (585nm) – Laser of ChoiceChoice
Fluence – 3 J/cmFluence – 3 J/cm22
Spot Size – 10 mmSpot Size – 10 mm
Mechanism – UnclearMechanism – Unclear
Sessions – 4-6 weekly intervalsSessions – 4-6 weekly intervals
Future Future
Atrophic scars : Non-ablative Atrophic scars : Non-ablative laserslasers
POST TRAUMATIC SCAR
POST SURGICAL SCAR
NASOLABIAL SCAR
PIGMENTED LESIONSPIGMENTED LESIONS
QS Nd: YAGQS Nd: YAG
QS ALEXANDRITEQS ALEXANDRITE
PERIORBITAL PIGMENTATIONSPERIORBITAL PIGMENTATIONS
Seborrheic KeratosisSeborrheic Keratosis
TattoosTattoos1.1. Black pigmentBlack pigment
QS Nd:YAG (1046NM)QS Nd:YAG (1046NM)
QS ALEXANDRITE (755 NM Versa QS ALEXANDRITE (755 NM Versa
pulse coherent)pulse coherent)
2. Blue & green pigments2. Blue & green pigments
QS ALEXANDRITE (755 nm)QS ALEXANDRITE (755 nm)
3. Red, orange & yellow3. Red, orange & yellow
QS Nd:YAG (532nm)QS Nd:YAG (532nm)
FPPDL (510nm)FPPDL (510nm)
AMATEUR TATTOOAMATEUR TATTOO
PROFESSIONAL TATTOOPROFESSIONAL TATTOO
MULTICOLOURED MULTICOLOURED TATTOOTATTOO
HAIR REMOVALHAIR REMOVAL
Hair follicle thermal relaxation time : Hair follicle thermal relaxation time : 10-100 milli seconds10-100 milli seconds
Cooling system: Decreases epidermal Cooling system: Decreases epidermal injuryinjury
Lasers & IPL (600-1200nm)Lasers & IPL (600-1200nm)
QS & LP Nd:YAG (1064 nm)QS & LP Nd:YAG (1064 nm)
LP Alexandrite (775 nm)LP Alexandrite (775 nm)
Pulsed Diode (800 nm)Pulsed Diode (800 nm)
IPL (590-1200 nm)IPL (590-1200 nm)
HAIR REMOVAL
HAIR REMOVAL
CONCLUSIONCONCLUSION
Principles – simple
Technique – easy
Applications – unique
Results - outstanding
THANK YOUTHANK YOU