lasers in oral 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