1. Lasers in Oral & Maxillofacial
Surgery

2. L ight
A mplification by
S timulated
E mission of
R adiation

3. Contents
• Historical background
• Laser physics
• Photobiology of Lasers
• Laser safety
• Types of Lasers
• Clinical Applications
• Medico legal considerations in Laser Surgery
• Future Trends

4. Historical background
•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

5. Laser physics
ELECTROMAGNETIC SPECTRUM
ALEXANDRITE
ERBIUM-YLF
KRYPYON
EXCIMER
Nd: YAG
Ho:YAG
ARGON
HE NE
RUBY
KTP
CO2
X - RAYS
TV & RADIO WAVES
Frequency 1020 1019 1018 1017 1016 1015 1014 1013 1012 1011 1010 109 108 107 106 105 104 103 102 101 100
3AO 3nm 3µm 3mm 3cm 3m
Wave length 3km
MICROWAVES
GAMMA WAVES
ULTRAVIOLET VISIBLE LIGHT INFRARED
IONISING NON - IONISING

6. 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.

7. 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

8. 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

9. • 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

14. OUTPUT MODES

15. OUTPUT MODES

16. OUTPUT MODES

18. TISSUE EFFECTS
Temperature Visual Change Biological changes
37-60˚C No change Warming, welding
60-65 ˚C Blanching Coagulation
65-90 ˚C White/gray Protein denaturization,
necrosis
90-100 ˚C Puckering Drying
100-150 ˚C Plume Vaporization
150-210 ˚C Carbonization Potential Scar

19. PATTERNS

20. DOSIMETRY
1. ENERGY
2. POWER
3. POWER DENSITY
4. FLUENCE
5. SPOT SIZE
6. PULSE ENEGEY
7. THERMAL RELAXATION TIME

21. COMPLICATIONS
1. Herpes Simplex
2. Dyschromias
3. Scarring
4. Eye and Teeth Injuries

22. LASER SAFETY
Reflection
Electrical
Pollution
Fire
Shutdown

23. OCULAR PROTECTION

24. OCULAR PROTECTION

26. COMMONLY USED LASERS
TYPE USE
1) Erbium:YAG (pulsed) Ablative skin resurfacing, epidermal
(2490 nm) lesions
2) Nd: YAG, frequency-doubled (532 Pigmented Lesions,
nm) red/orange/yellow tattoos
Nd : YAG (1064 nm)
QS Pigmented lesions, blue/black
tattoos
Normal mode Hair removal, leg veins, non-
ablative dermal remodelling
Nd: YAG, long- pulsed Non-ablative dermal remodelling
(1320 nm)

27. 3) Alexandrite (755 nm)
QS Pigmented lesions,
blue/black/green tattoos
Normal mode Hair removal, leg veins
4) Pulsed dye (510 nm) Pigmented lesions
(585-595 nm) Vascular lesions,
hypertrophic/keloid scars, striae,
verrucae, nonablative dermal
remodelling

28. First Laser

29. PRESENT LASERS

30. PRESENT LASERS

31. HAND PIECE

32. HAND PIECE

33. RECENT ADVANCES
1. 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

34. CLINICAL
APPLICATIONS

35. 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

36. TECHNIQUE

38. PHOTO DAMAGE

39. DEPRESSED SCARS

40. VASCULAR LESIONS
Chromophore – Oxyhaemoglobin
Absorption wavelengths – 418, 542, 577 nm
Laser of Choice : FPPDL – wavelength – 585, 590,
595, 680 nm
Cooling System
Filters
Fluence –5-14 J/cm2
Spot Size – 2-10 mm
Density – Less than 10%
Pulse Duration : 1.5-40 milliseconds
Delay between pulses – 10-500 milliseconds

41. PORTWINE HAEMANGIOMA

42. Nasal Telangiectasias

43. HYPERTROPHIC SCARS, KELOIDS &
STRIAE DISTANSAE
FPPDL (585nm) – Laser of Choice
Fluence – 3 J/cm2
Spot Size – 10 mm
Mechanism – Unclear
Sessions – 4-6 weekly intervals
Future
Atrophic scars : Non-ablative lasers

44. POST TRAUMATIC SCAR

45. POST SURGICAL SCAR

46. NASOLABIAL SCAR

47. PIGMENTED LESIONS
QS Nd: YAG
QS ALEXANDRITE

48. PERIORBITAL PIGMENTATIONS

49. Seborrheic Keratosis

50. Tattoos
1. Black pigment
QS Nd:YAG (1046NM)
QS ALEXANDRITE (755 NM Versa
pulse coherent)
2. Blue & green pigments
QS ALEXANDRITE (755 nm)
3. Red, orange & yellow
QS Nd:YAG (532nm)
FPPDL (510nm)

51. AMATEUR TATTOO

52. PROFESSIONAL TATTOO

53. MULTICOLOURED
TATTOO

54. HAIR REMOVAL
Hair follicle thermal relaxation time : 10-
100 milli seconds
Cooling system: Decreases epidermal injury
Lasers & IPL (600-1200nm)
QS & LP Nd:YAG (1064 nm)
LP Alexandrite (775 nm)
Pulsed Diode (800 nm)
IPL (590-1200 nm)

55. HAIR REMOVAL

56. HAIR REMOVAL

57. CONCLUSION
Principles – simple
Technique – easy
Applications – unique
Results - outstanding

58. THANK YOU