seminar on oral and maxillofacial surgery

1. LASERS IN ORAL &
MAXILLOFACIAL SURGERY
DR. JEFF ZACHARIA
POST GRADUATE STUDENT
AJ INSTITUTE OF DENTAL SCIENCES

2. CONTENTS
1. Introduction
2. History
3. Properties of Laser
4. Laser unit
5. Classification of lasers
6. Indications of Lasers
7. Precautions before & during
irradiation
2
9. Selection of Lasers
10. Summary of types of Lasers
11. Complications
12. Safety concerns
13. Conclusion

3. INTRODUCTION
• LASER is an acronym for Light Amplification By Stimulated Emission Of Radiation.
• A laser beam is an electromagnetic beam of radiation which can fall anywhere in the
spectrum of visible or invisible light.
• The laser, as opposed to a regular light source, is composed of monochromatic, coherent
and collimated beams, which, when they strike a suitable target, create photoacoustic,
photochemical, photo-ablative, and photothermal effects
3

4. HISTORY
• 1917: Einstein introduced the idea of Laser based on
the theory of Stimulated emission
• 1960: Maiman built the first functioning Laser
• 1961: Johnson developed Laser generated from crystals
of Yttrium, Aluminum and Garnet treated with 1 – 3 %
Neodynum
• 1962: Bennet developed the Argon Laser
• 1964: Patel developed the CO2 Laser

5. PROPERTIES OF LASER
• Monochromatic
Refers to a single wavelength of light.
• Directional
The radiation is produced in a beam that is spatially narrow and
has low divergence
• Coherent
Waves of the light emitted have a constant relative phase.
• Collimated
Perfectly parallel beam of directional light

6. LASER PHYSICS

7. STIMULATED ABSORPTION
• Electrons are usually found in the low energy state/ground state.
• These electrons can be excited by an external source (photons)
• The photon can push the electron from a low energy state to a high energy state and absorb the
photon’s energy. 7

8. SPONTANEOUS EMISSION
• The excited electron in the higher energy state is
very unstable and falls back to the ground state
during which energy is released.
• The higher the fall, the higher the energy released.
8

9. STIMULATED EMISSION
• This occurs when a photon interacts with an electron in the
higher energy state.
• This forces the electron back into the lower energy state
thereby releasing energy (photons) from the ionized
electron.
• These photons tend to be identical and travel together in
the same direction.
9

10. LASER UNIT

11. LASER CAVITY
• It is composed of
• An active medium
• An excitation source
• An optical resonator
• The active medium is the chemical that undergoes stimulated emission.
• The photons of energy produced are collimated & amplified to produce a laser beam which is
then focused using a mirror to create a focal point.
11

12. DELIVERY SYSTEMS
Articulated arms
• Consists Hollow tubes and 45° mirrors at each joint
• Mirrors reflect the energy down the length of the tube
• A misalignment of the mirrors could cause a drop in the amount of
energy transmitted.
Hollow wave guide
• Consists of a semi rigid tube with reflective interior mirror finish
• Laser energy is reflected along this tube and exits through a handpiece
at the surgical end with the beam striking the tissue in a non contact
fashion

13. Optic fiber
• Fits into a handpeice
• Used in contact or non contact mode
• Focal point is near the tip which has the greatest energy
Hand held unit
• Low level lasers
• Induce photoreactions in cells through light stimulation which
is called photo-biostimulation. Power of these lasers is usually
under 250mW
• Can induce the stimulatory effects without thermal effects

14. MODES OF LASER BEAM
1. Pulsed mode
 Allows tissue to cool before the next pulse of laser radiation is started.
 The time between pulses can help avoid thermal effects on
surrounding tissues or excessive thermal effects on target tissues.
2. Continuous mode
 Wave of laser must be stopped manually to allow tissues to cool.
 Useful in ablative procedures or coagulation
14

15. VARIABLES THAT ARE CONTROLLED BY THE SURGEON
• The physician can control three variables:
– Spot size (measured in millimeters)
– Power (measured in watts)
– Exposure time (measured in seconds).
15

16. • Spot size
• It is the width of the laser beam on the target.
• At the focal point, maximum energy is focused to produce the smallest
spot size or the thinnest possible incision but to the greatest depth.
• Power
• May be kept constant with widely varying effects, depending on the
spot size & duration of exposure
• Exposure time
• The surgeon can vary the amount of energy delivered to the target
tissue by varying the exposure time.
16

17. LASER OPERATION PARAMETERS
• Laser beam hits tissue at its focal point (narrowest diameter)
• Cutting mode
• Beam moved away from its focal point.
• Wider area of tissue affected as beam diameter increases.
• Ablative mode.
FOCUSED BEAM
DE-FOCUSED BEAM

18. • There is direct contact between the tip and the target
tissue.
• The tissue absorbs the radiant energy and becomes hot
resulting in vaporization of the target cells
• Concentrated delivery of laser energy.
• Char tissue formation at tip.
• Tactile feedback is available
• Eg, Nd: YAG laser
NON-CONTACT LASER
CONTACT MODE
• There is no direct contact with the tissue. The
laser light transfers radiant energy to the
tissue resulting in vibration of the molecules
in the tissue
• Tip is kept 0.5 to 1 mm away from tissue.
• E.g, CO2 laser
LASER OPERATION PARAMETERS

19. EFFECTS OF TEMPERATURE
19

20. CLASSIFICATION OF LASERS

21. 21
BASED ON THE ACTIVE MEDIUM

22. ACCORDING ITS SPECTRUM OF LIGHT, MATERIAL USED AND HARDNESS
Soft tissue Lasers
1. Helium-neon (He-N) at 632.8 nm
2. Gallium- arsenide (Ga-As) at 830 nm
Hard tissue Lasers
1. Argon lasers (Ar) at 488 to 514 nm
2. Carbon-dioxide lasers (CO2) at 10.6 micro-meter
3. Neodymium doped yttrium aluminum garnet 1.064 micrometer.
4. Holmium Yttrium Aluminum Garnet (Ho:YAG) at 2:1.micro-meter.
5. Erbium, Chromium, Yttrium, Selenium - Gallium- Garnet (Er,Cr:YSGG) at 2.78 micro-meter.
6. Neodymium Yttrium-Aluminum-Perovskite (Nd:YAP) at 1,340 nm.
22

23. TYPES OF LASERS
• On the basis of output of energy
• Low output, soft or therapeutic eg. Low-output diodes
• High output, hard, or surgical eg.CO2,Nd:YAG,Er:YAG
• On basis of state of gain medium
• Solid state- E.g. Nd:YAG, Er:YAG, Er,Cr:YAG
• Gas- E.g., Argon, CO2
• Excimer- E.g. ArF, KrCl
• Diode- E.g. GaAIAs
• On the basis of oscillation mode
• Continuous wave E.g. CO2, Diodes
• Pulsed wave E.g. Nd: YAG, Er: YAG
23

24. INDICATIONS OF LASERS

25. INDICATIONS OF LASERS
Surgical indications in children
• Congenital Vascular malformations such as hemangiomas or naevi
flammeus. Treated by Argon, Nd: YAG
• Cleft surgery: CO2 lasers can be used
TMJ laser assisted surgery
• Discectomy, Discoplasty, synovectomy, posterior attachment contraction &
eminectomy can be performed in Out patient basis using 2 incisions less
than 2 mm each. 25

26. Intramucosal surgery
• Common applications include
 incisional/excisional biopsy
 frenectomy
 Ablation of premalignant lesions
 Prosthetic procedures
 Vestibuloplasty
 Excision of epulis fissuratum
26

27. Cosmetic facial surgery
• Lasers can be used for skin resurfacing
 The superficial layers of the epidermis and papillary dermis are removed leaving
the reticular layer of dermis.
 This layer provides epithelial cells that are required for rapid re-epithelialization.
• In blepharoplasty
 Lasers can be used to excise muscle or fat with excellent hemostasis, provides
great visualization and tissue control.
• In endoscopic brow lift
 Lasers are passed through flexible fibreoptic cables or through small diameter
hollow waveguide extensions in order to be used for incisions made within the
optic cavity and is used to incise the periosteum and/or muscle attachments.
27

28. Laser osteotomy
• Intraoperative fluorescence-guided resection followed by PDT seem to be
highly promising in improving the radicality of tumor resection combined
with a conventional therapeutic approach.
Implantology
• Er:YAG has been used for uncovering a thin layer of bone in second stage
implant and initiating the implant osteotomy.
• Advantages include precision, atraumatic bone handling, bloodless field of
view and decontamination of sites.
28

29. Oral cancer & premalignant lesions
• Vaporization or ablation of tissues intraorally is usually performed on
premalignant lesions such as hyperkeratosis or mild epithelial dysplasias.
• More severe dysplasias are best excised using lasers to allow for margin control.
• Advantages: Remote application, precise cutting, hemostasis, low cicatrization,
reduced post-operative pain and swelling, can be combined with endoscopic,
microscopic and robotic surgery.

30. PRECAUTIONS BEFORE & DURING
IRRADIATION

31. PRECAUTIONS
• Use glasses for eye protection (patient, operator, and assistants).
• Prevent inadvertent irradiation (action in non-contact mode).
• Protect the patient’s eyes, throat, and oral tissues outside the target site.
• Use wet gauze packs to avoid reflection from shiny metal surfaces.
• Ensure adequate high speed evacuation to capture the laser plume
31

32. SELECTION OF LASER

33. CO2 LASER (PATEL IN 1964)
• Mixture of CO2, Nitrogen and Helium.
• Most commonly used laser in oral cavity
• Wavelength: 10,600 nm.
• Shallow depth of penetration 0.2mm
• Uses an articulated arm to deliver the beam
• Little scatter ,reflection, transmission 33

34. • Has an excellent affinity towards water
• The absorbed energy causes vaporization of the intracellular fluid causing tissue vaporization,
while lateral heat causes contraction of collagen & closure of blood vessels.
• Uses: For excision and ablation of superficiallesions
34

35. Leukoplakia
• A randomized clinical trial compared the pain and swelling after removal of oral leukoplakia with
CO2 laser and cold knife. They concluded that CO2 laser caused only minimal pain and swelling,
thus suggesting that it may be an alternative method to conventional surgery in treating patients
with oral leukoplakia.
• Yang et al. evaluated the associated factors of recurrence in patients who received laser surgery
for dysplastic oral leukoplakia. This study suggested that continuous smoking after surgical
treatment and widespread multiple-focus lesions are the prognostic indicators for recurrence
after laser surgery.
35

36. Lichen planus
• Agha-Hosseini et al (2012) compared low level laser & CO2 laser in the treatment of patients with
oral lichen planus. They showed that low-level laser displayed better results than CO2 lasers as an
alternative or additional therapy
• de Magalhaes et al presented a case report of a histologically diagnosed oral lichen planus
excised by CO2 laser. The patient was followed up over 1 year with no signs of lesion recurrence.
The use of the CO2 laser was found to be useful and effective to treat lichen planus
36

37. Gingival melanin pigmentation
• A clinical and histologic study compared surgical stripping between Er: YAG and CO2 laser techniques
for gingival depigmentation. They concluded that clinical re-pigmentation after gingival
depigmentation is an outcome of histologic changes in the melanocyte activity and density of the
melanin pigments. Surgical stripping for gingival depigmentation remains the gold standard.
However, Er: YAG laser and CO2 lasers can be effectively used
Mucocele
• Yague-Garcia et al compared oral mucocele resection with the scalpel versus the CO2 laser. Their
results showed that oral mucocele ablation with the CO2 laser offered more predictable results and
fewer complications and recurrences than conventional resection with the scalpel.
37

38. Ranula
• Lai et al presented a case series report on the use of carbon dioxide laser treatment for ranula
and reported that that carbon dioxide laser excision of ranula was safe with minimal or no
recurrence.
Lymphangioma
• In a case report, treatment of lymphangioma with CO2 laser was described. CO2 laser application
(focused CO2 laser beam, 10.600 nm) was performed at 3 watt (W), continuous wave (CW) with
90 degree angle tip under local anesthesia. They concluded that CO2 laser therapy can be used as
a primary alternative method in the treatment of lymphangiomas. It can be safely used and
recurrence may be less than conventional excision with scalpel.
38

39. ARGON LASER (BRIDGES 1964)
• Wavelength: 488-514 nm
• Delivered with fibre optic cable and hand piece
• Argon beam is highly absorbed by hemoglobin and malanin
• an excellent hemostatic laser.
• Used to excise gingival soft tissue lesions, pigmented lesions and in the treatment of vascular
hemangiomas.
• The poor absorption into enamel and dentin is advantageous when using this laser for cutting and
sculpting gingival tissues because there is minimal interaction and thus no damage to the tooth
surface during those procedures 39

40. ND:YAG (GUESIC 1964)
• Neodymium Yttrium Aluminum Garnet
• Wavelength of 1064 nm
• Used with specially designed sapphire or ceramic tips and used as contact
laser scalpel or ablation tool, with excellent hemostasis and cutting abilities.
Uses:
• Treatment of vascular lesions
• Intraoral and extraoral pigmented lesions
• Open TMJ arthroplasty
• Excision of malignant lesion
40

41. POTASSIUM TITANYL PHOSPHATE (KTP) LASER
• Modified version of Nd:YAG laser
• Wavelength : 532 nm
• Low wavelength prevents penetration into deeper vascular tissues.
• Used in treatment of vascular and pigmented lesions, tattoo
removal, blepharoplasty, endoscopic procedures.
41
• A clinical study described the application of the KTP Laser (532 nm), used with low power
parameter (1 Watt – CW) to evaluate the intra and postoperative pain. The authors proposed that
KTP laser with low parameters permits to perform oral surgery with good pain control and good
wound healing

42. HO:YAG LASER
• Holmium yttrium aluminum garnet
• Wavelength: 2140 nm.
• An aiming beam with fibre optic cable is used for delivery
• Used in both contact and noncontactmode.
• Well absorbed by synovium and joint surface.
• Extensively used in endoscopic orthopedic surgery
• Used in TMJ for lysis of adhesions and sculpting of
fibrocartilaginous disk tissue.
42

43. ER:YAG LASER
• Erbium : Yttrium Aluminum Garnet
• Wavelength :2940 nm
• Laser for facial resurfacing ,incision andablation of soft tissues.
• It allows re-organization of collagen with less energy.
• Advantage: Ability to remove superficial skin layers more
precisely than CO2 laser.
43

44. Mucocele
• Boj et al described the case of a 4-mm extravasation mucocele located on the lower lip with an
erbium laser. They showed the wound healed excellently and rapidly without sutures. No relapse
was observed a year after the surgery and reported that Lasers are useful for soft tissue surgery
in pediatric dentistry, as operations are rapid and wounds heal well without sutures.
44

45. DIODE LASER
• Lasing media: Aluminum Gallium and arsenide
• Wavelength 800-980 nm
• The power output utilized by the soft-tissue diode laser is
typically between 0.1 and 10 Watts
• Advantage: Smaller sized portable instrument
• Useful in soft tissue surgeries, ablative procedure &
periodontal treatment
45

46. Lichen planus
• Misra et al (2013) evaluated the efficacy of diode laser (940 nm) in the management of oral
lichen planus. Their results demonstrated that diode laser therapy seemed to be an effective
alternative treatment for relieving the symptoms of Oral lichen planus.
Gingival melanin pigmentation
• Simsek et al compared the use of diode and Er:YAG lasers in treating gingival melanin
pigmentation. Their results demonstrated the total length of treatment was significantly shorter
with the diode laser than with the Er:YAG laser.
46

47. Fordyce granules excision
• Baeder (2010) presented a case report on the use of high power diode laser in Fordyce granule
excision in a 19-year-old male and reported excellent esthetic results & effectiveness of both
high- and low-intensity laser therapies on the excision of Fordyce granules
Gingival Hyperplastic lesions
• Asnaashari et al applied 810 nm Diode laser to remove all of gingival hyperplastic lesions. Their
results demonstrated that a perfect shaping was obtained after removal of the whole lesion in
one session and no recurrence was observed in 6 months. 47

48. SUMMARY OF TYPES OF LASERS
48

49. ADVANTAGES OF LASER
• Precision
• Better hemostasis
• Improved tissue healing
• Decreased scarring
• Decreased post-operative pain
49
DISADVANTAGES OF LASER
• Hard tissue lasers are slower than
conventional tools such as burs or
saws
• Tissue healing is slower
• Expensive equipment

50. COMPLICATIONS AND SAFETY CONCERNS

51. COMPLICATIONS
• Post-operative infection
• Contact dermatitis
• Post-operative pain
• Airway fire
• Ocular injuries
• Hyper-pigmentation
• Erythema
• Hypertrophic scarring 51

52. SAFETY CONCERNS WITH USE OF LASERS
• Personnel protection
• Any reflective surface can divert the beam away from the
intended area and potentially cause harm.
• Use of special protective wear can help avoid injury to the eyes of
the patient or personnel.
• Fire Hazard
• Lasers in O2 rich environment such as oral cavity of a patient with
an ET tube can pose a significant fire risk.
• Compressed air can be substituted for O2 to keep the inspired
conc. of O2 below 30%
52

53. • Laser Plume
• When laser is used for incision and or vaporization, the tissue
being handled will create a plume which consists of potentially
hazardous particulate debris which is considered infectious.
• High flow suction made of a non reflective material should be
used to remove the plume.
• Protective barriers such as masks and eye wear helps avoids
exposure
53

54. CONCLUSION

55. CONCLUSION
• Lasers have changed the Oral & Maxillofacial surgery practice significantly to a point that it is an
essential surgical tool.
• Use of lasers in hard tissue is somewhat limited in comparison to soft tissue applications.
• Development of lasers in the future may overcome current disadvantages and increase utility and safety.
• Further research and development could help improve this aspect of lasers.
55

56. THANK YOU