Local anesthesia in oral surgery and technique

local anarestia complication

1. Local anesthesia in Oral and
maxillofacial surgery

2. Maxillary Injection
Techniques

3. Anatomy

5. Atraumatic Injection Protocol

6. 3 Main Types of Maxillary Injections:
1) Local Infiltration
2) Field Block
3) Nerve Block

7. Local Infiltration
•Incision (treatment) is done in the same area in which the
local anesthetic was deposited (interproximal papilla
before Scaling and Root Planing)

8. Field Block
•Local anesthetic is deposited toward larger nerve terminal
branches
•Treatment is done away from the site of local anesthetic
injection
•Maxillary injections administered above the apex of the tooth
to be treated are properly referred to as field blocks not local
infiltrations

9. Nerve Block
•Local anesthetic is deposited close to a main
nerve trunk, usually at a site removed from the
area of treatment (PSA, IANB)

10. Types of Injections
1) Supraperiosteal Injection
2) Intraligamentary (PDL) Injection
3) Intraseptal Injection
4) Intracrestal Injection
5) Intraosseous Injection
6) Posterior Superior Alveolar (PSA) Nerve Block
7) Middle Superior Alveolar (MSA) Nerve Block
8) Anterior Superior Alveolar (ASA) Nerve Block
9) Maxillary Nerve Block (2
nd
Division)
10) Greater Palatine Nerve Block
11) Nasopalatine Nerve Block
12) Anterior Middle Superior Alveolar (AMSA) Nerve Block
13) Palatal Approach Anterior Superior Alveolar (P-ASA) Nerve Block

11. Supraperiosteal Injection

12. 1) Supraperiosteal Injection
Used for pulpal anthesia in maxillary teeth
Anesthetizes large terminal branches of the
dental plexus
Greater than 95% success rate
1 or 2 teeth

13. Supraperiosteal Injection
Dense bone covering the apices of the teeth can lead to
failure
-maxillary molar of children (zygomatic bone
obscures)
-central incisor of adults (nasal spine obscures)
Negligible positive aspiration rate (less than 1%)
Should not be used for large areas (multiple sticks/large
amount of local anesthetic solution must be used)

14. Technique  Supraperiosteal Injection
1) 25 or 27 gauge short needle is recommended
2) Insert needle at height of mucobuccal fold
over apex of desired tooth
3) Apply topical anesthetic for at least one
minute
4) Orient bevel toward bone; lift lip pulling
tissues taut

15. 5) Hold syringe parallel to long axis of the tooth
being anesthetized
6) No resistance to penetration should be felt and no
patient discomfort
7) Aspirate twice
8) Deposit .6 ml (one-third of a cartridge) into tissue
over 20 seconds
9) Do not allow tissues to balloon
10) Wait 3 to 5 minutes to begin dental treatment

16. Problems/Failures
If tooth does not anesthetize the needle tip could be
below the apex of the tooth resulting in inadequate
anesthesia
If the needle lies too far from the bone then
anesthesia will be inadequate because the solution
was deposited in the soft tissue (lip)
The needle must be oriented toward the periosteum
but should be managed properly to avoid tearing the
highly innervated periosteum

19. Posterior Superior Alveolar
Nerve Block (PSA)

20. 2) Posterior Superior Alveolar Nerve Block
Highly successful nerve block with greater than
95% success
Effective for maxillary 1
st
, 2
nd
and 3
rd
molars and
buccal periodontium
Mesiobuccal root of the maxillary 1
st
molar is not
consistently innervated by the PSA nerve

21. Short dental needle is used for all but the
largest of patients
Average depth of soft tissue penetration is 16
mm (short needle is 20 mm in length)
28% of maxillary 1
st
molars’ mesiobuccal
roots are innervated by the middle superior
alveolar nerve (MSA)

22. When the risk of hemorrhage is too great as
with a hemophiliac, you should use the
supraperiosteal or PDL injections
Patient should feel no pain with this injection
because bone is not contacted and there is a
large area of soft tissue into which the solution
is deposited

23. Positive aspiration risk is 3.1%
Patient will often say that they do not feel
numb; reason why is because they are
accustomed to the intense feeling of anesthesia
experienced by the IANB; reassure patient that
you are going to make sure they are
comfortable during the procedure

24. Technique  PSA Nerve Block
1) 25 gauge short needle is recommended
2) Insert needle at the height of the mucobuccal
fold above the maxillary 2
nd
molar
3) Target area is the PSA nerve which is
posterior, superior and medial to the posterior
border of the maxilla

25. 4) Apply topical anesthetic for at least one minute
5) Have patient open their mouth half way which
makes more room
6) Retract the patient’s cheek with mirror
7) Pull the tissues taut
8) Orient bevel toward bone

26. 9) Insert needle at height of mucobuccal fold over the
2
nd
maxillary molar
10) Advance needle upward, inward and backward
direction
11) Odd feeling of having no resistance whatsoever

12) Penetrating to an average depth of 10-14 mm is
adequate
13) Aspirate in two planes by rotating bevel one
quarter turn

27. 14) Deposit 0.9 ml of a cartridge (1/2 cartridge)
15) Wait 3 to 5 minutes to start treatment
Advance the needle in one movement, not three
separate movements; usually atraumatic to most
patients

28. Problems/Failures (PSA)
Hematoma formation if needle is overinserted too
far posteriorly
Pterygoid plexus of veins leads to this hematoma
Visible intraoral hematoma develops within
minutes; bleeds until the pressure of the
extravascular blood equals that of the intravascular
blood which can result in a large, unsightly
hematoma

29. Patients will usually claim that they do not
feel any anesthesia which is not uncommon
because patients can not reach this area to
gauge their own level of anesthesia
If using a long dental needle the maximum
insertion should be one-half on its length or
16 mm
Problems/Failures (PSA)

34. Middle Superior Alveolar
Nerve Block (MSA)

35. Technique  MSA Nerve Block
1) 25 or 27 gauge long or short needle
2) Insert needle at the height of the mucobuccal
fold above 2
nd
maxillary premolar
3) Target is the maxillary bone above the
apex of the 2
nd
maxillary premolar

36. 4) Orient bevel toward bone to avoid
tearing periosteum
5) Apply topical anesthetic for one minute
6) Pull tissues taut
7) Penetrate tissues placing bevel of needle
well above the apex of the 2
nd
maxillary
premolar

37. Technique- Middle Superior Alveolar Nerve Block
8) Aspirate
9) Slowly deposit 0.9-1.2 ml of solution
10) Wait 3 to 5 minutes before starting
treatment

38. Problems/Failures MSA
Anesthetic not deposited above the apex of the
2
nd
premolar
Solution deposited into the soft tissue too far
from the periosteum (lip)
Hematoma may develop; Dentist should apply
pressure to the area with gauze for at least
sixty (60) seconds; up to 2 to 3 minutes

40. Anterior Superior Alveolar
Nerve Block (ASA)

41. When Do I Use This Block?
1) Dental procedures involving more than
one tooth, i.e., central and lateral incisor
2) Inflammation/Infection precluding the use
of the supraperiosteal injection
3) Ineffective supraperiosteal injections due
to dense cortical bone

42. Technique  ASA Nerve Block
1) 25 gauge long needle is recommended
2) Insert needle at the height of the mucobuccal fold
over the 1
st
premolar
3) Target: Infraorbital Foramen
4) Landmarks: Infraorbital Notch, Mucobuccal fold,
Infraorbital Foramen
5) Apply topical anesthetic for at least one minute

43. 6) Feel the infraorbital notch moving your finger
down the notch palpating the tissues gently; the
outward bulge is the lower border of the orbit
which is the roof of the infraorbital foramen;
continue the finger inferiorly until a depression
is felt which is the infraorbital foramen
7) Maintain pressure over the foramen while
inserting the needle down the long axis of the
1
st
premolar

44. 8) Advance the needle slowly until bone is contacted
gently which is the upper rim of the infraorbital
foramen
9) 16 mm total advancement of needle;1/2 of long
needle length
10) Estimate the distance between the infraorbital
foramen and mucobuccal fold
11) Aspirate

45. 12) Deposit 1.0 ml of anesthetic solution
13) Administrator can feel the anesthetic expanding
the tissue with finger tip
14) Maintain finger pressure over the foramen for
at least one minute to disperse the anesthetic
solution
15) Needle should not be palpable in most patients
16) Wait 3 to 5 minutes for anesthesia to result

46. Problems/Failures (ASA)
Failure is from the needle deviating to the medial or
lateral away from the infraorbital foramen
Failure to reach the infraorbital foramen will result
in anesthesia of the lateral side of the nose, upper
lip and lower eyelid but not the teeth
Hematoma formation can result although rarely;
apply pressure to area for 2 to 3 minutes; at least 60
seconds

51. Palatal Anesthesia

52. Palatal Anesthesia
Easily one of the most traumatic experiences
for dentists due to the pain that is sometimes
elicited from the patients
Palatal injections can be administered
atraumatically

53. STEPS- Results in painless palatal injections
1) Apply topical for two minutes
2) Apply pressure to site both before and
during deposition of the solution
3) Deposit solution slowly

54. PALATAL INJECTIONS
1) Anterior (Greater) Palatine Nerve Block:
no pulpal anesthesia

2) Nasopalatine Nerve Block: no pulpal
anesthesia
3) Local Infiltration: no pulpal anesthesia

55. Greater Palatine Nerve Block

56. GP Nerve Block (soft tissue and bone only)
Anesthetizes palatal soft tissue distal and
medially to the canine
(posterior portion of the palate)
Tissues around the Greater Palatine Foramen are
able to accommodate a larger volume of
solution than the tissue in the vicinity of the
Nasopalatine Foramen  less patient
discomfort

57. Technique  Greater Palatine Nerve Block
1) 27 gauge short needle
2) Insert needle in soft tissue slightly anterior
to the greater palatine foramen
3) Target is the greater palatine nerve as it
passes from the foramen between the soft
tissue and bone of the hard palate

58. 4) Foramen is most often located distal to the
2
nd
maxillary molar
5) Apply considerable pressure to cotton swab
in area of foramen until a noticeable ischemia
occurs; hold pressure for 30 seconds before
injection

59. 6) Continue to apply pressure throughout the
injection with the cotton swab
7) Slowly advance the needle until bone is
gently contacted
8) Depth of penetration is usually less than 10 mm
9) Aspirate
10) Deposit solution very slowly

60. Do not enter the greater palatine canal
There is no reason to have the needle
penetrate the canal
There is no negative repercussion except
post-operative pain

63. Nasopalatine Nerve Block

64. Technique  Nasopalatine Nerve Block
1) 27 gauge short needle is recommended
2) Insertion point: palatal mucosa just lateral to the
incisive papilla
3) Approach the injection site at a 45 degree angle
4) Apply topical anesthetic for two minutes
5) Apply considerable pressure to the incisive papilla
until ischemia

65. 6) Continue to apply pressure to the cotton applicator
tip while injecting
7) Advance the needle until bone is gently contacted

8) Depth of needle penetration is usually 5 mm
9) Slowly deposit ¼ cartridge over a 30 second
interval
10) Wait 2-3 minutes for anesthesia

66. Other Than P-ASA and
Maxillary Nerve Blocks
There is no reason to enter the Greater
Palatine Foramen or the Nasopalatine
Foramen when providing these injections
do not advance needle more than 5 mm
into the incisive canal because it could
enter the floor of the nose causing infection

67. Local Infiltration of the Palate

68. Local Infiltration of the Palate
Anesthetizes the terminal branches of the Greater
Palatine Nerve and Nasopalatine Nerve
Anesthetizes the soft tissue in the immediate
vicinity of the injection

69. Indications for Palatal Anesthesia:
1) Hemostasis during procedures of a minimal
area of tissue
2) Palatogingival pain control for rubber dam
clamps, retraction cord placement and small
surgical procedures

70. Local Infiltration of the Palate
Important Points:
-Gate control method (inhibitory neuron prevents the
projection neuron from sending signals to the brain
(gate is closed)) of pain removal is used with
-these injections using a cotton swab for pressure
resulting in blanching tissue
-Target area is the palatal tissue 5 to 10 mm from the
free gingival margin
-Masticatory mucosa of the hard palate is only
3 to 5 mm thick
-Palatal Infiltrations are safe areas anatomically to
deposit anesthetic

74. Mandibular anesthesia
techniques

75. Mandibular Anesthesia
Lower success rate than Maxillary anesthesia -
approx. 80-85 %
Related to bone density
Less access to nerve trunks
  

76. Mandibular Nerve Blocks
Inferior alveolar
Mental - Incisive
Buccal
Lingual
Gow-Gates
Akinosi

77. Mandibular Anesthesia
Most commonly performed technique
Has highest failure rate (15-20%)
Success depends on depositing solution within 1 mm of
nerve trunk

78. Inferior Alveolar Nerve Block
Not a complete mandibular nerve block.
Requires supplemental buccal nerve block
May require infiltration of incisors or mesial root
of first molar

79. Inferior Alveolar Nerve Block
Nerves anesthetized
Inferior Alveolar
Mental
Incisive
Lingual

80. Inferior Alveolar Nerve Block
Areas Anesthetized
Mandibular teeth to midline
Body of mandible, inferior ramus
Buccal mucosa anterior to mental foramen
Anterior 2/3 tongue & floor of mouth
Lingual soft tissue and periosteum

81. Inferior Alveolar Nerve Block
Indications
Multiple mandibular teeth
Buccal anterior soft tissue
Lingual anesthesia

82. Inferior Alveolar Nerve Block
Contraindications
Infection/inflammation at injection site
Patients at risk for self injury (eg. children)

83. Inferior Alveolar Nerve Block
10%-15% positive aspiration

84. Inferior Alveolar Nerve Block
Alternatives
Mental nerve block
Incisive nerve block
Anterior infiltration

85. Inferior Alveolar Nerve Block
Alternatives (cont.)
Periodontal ligament injection (PDL)
Gow-Gates
Akinosi
Intraseptal

86. Inferior Alveolar Nerve Block
Technique
Apply topical
Area of insertion:
medial ramus, mid-coronoid notch,
level with occlusal plane (1 cm above),
3/4 posterior from coronoid notch to
pterygomandibular raphe
advance to bone (20-25 mm)

87. Inferior Alveolar Nerve Block
Target Area
Inferior alveolar nerve, near mandibular
foramen

Landmarks
Coronoid notch
Pterygomandibular raphe
Occlusal plane of mandibular posteriors

88. Inferior Alveolar Nerve Block
Precautions
Do not inject if bone not contacted
Avoid forceful bone contact

89. Inferior Alveolar Nerve Block
Failure of Anesthesia
Injection too low
Injection too anterior
Accessory innervation
-Mylohyoid nerve
-contralateral Incisive nerve innervation

90. Inferior Alveolar Nerve Block
Complications
Hematoma
Trismus
Facial paralysis

97. Long Buccal Nerve Block
Anterior branch of Mandibular nerve (V3)
Provides buccal soft tissue anesthesia adjacent
to mandibular molars
Not required for most restorative procedures

98. Buccal Nerve Block
Indications
Anesthesia required - mucoperiosteum buccal
to mandibular molars
Contraindications
Infection/inflammation at injection site

99. Buccal Nerve Block
Advantages
Technically easy
High success rate
Disadvantages
Discomfort

100. Buccal Nerve Block
Alternatives
Buccal infiltration
Gow-Gates
PDL
Intraseptal

101. Buccal Nerve Block
Technique
Apply topical
Insertion distil and buccal to last molar
Target - Long Buccal nerve as it passes anterior border of
ramus
Insert approx. 2 mm, aspirate
Inject 0.3 ml of solution, slowly

- 25-27 gauge needle
Area of insertion:
- Mucosa adjacent to most distal

102. Buccal Nerve Block
Landmarks
Mandibular molars
Mucobuccal fold

103. Buccal Nerve Block
Complications
Hematoma (unusual)
Positive aspiration
0.7 %

106. Mental Nerve Block
Terminal branch of IAN as it exits mental
foramen
Provides sensory innervation to buccal soft
tissue anterior to mental foramen, lip and chin

107. Mental Nerve Block
Indication
Need for anesthesia in innervated area
Contraindication
Infection/inflammation at injection site

108. Mental Nerve Block
Advantages
Easy, high success rate
Usually atraumatic
Disadvantage
Hematoma

109. Mental Nerve Block
Alternatives
Local infiltration
PDL
Intraseptal
Inferior alveolar nerve block
Gow Gates

110. Mental Nerve Block
Complications
Few
Hematoma
Positive aspiration
5.7 %

115. The Gow-Gates Mandibular Block
ADVANTAGES
•Perceptible end point (bone)
•Fewer blood vessels at this level, therefore less
chance of positive aspiration
•Long buccal nerve anaesthesia likely
•Possible longer duration of anaesthesia
•Less chance of anaesthetizing accessory nerves 

116. Landmarks
•10 mm above the coronoid notch
•the internal oblique ridge
•the pterygomandibular raphe
•the neck of the condyle
•the contralateral mandibular bicuspids
•an imaginary line from the corner of the
mouth to the tragal notch of the ear
(extraorally).

117. Technique
•Ask the patient to open his or her mouth wide.
•Palpate the coronoid notch
•Move the finger or thumb superiorly
approximately 10 mm
 
•Insert the needle at a point between the
palpating fingernail and the pterygomandibular
raphe at the middle aspect of the fingernail

118. Technique
•Ensure that the barrel of the syringe is located
over the contralateral bicuspids.
 
•The angle of the needle and syringe is parallel
to the imaginary line from the corner of the
mouth to the tragus of the ear
•Insert until bone is contacted (at the neck of
the condyle), which should occur at a depth of
approximately 25 mm.

119. Onset and duration
•Onset for hard tissue anaesthesia is 4 to 12
minutes, with the anterior areas taking the
longest amount of time.
•The long buccal nerve will likely be
anaesthetized.

120. GG

121. •The Akinosi technique, also known as the Vazirani-Akinosi technique, is a closed-mouth injection method for administering local anesthetic to the mandibular nerve. It is useful for patients with limited mouth opening, such as those with trismus or ankylosis. In this technique, a needle is
inserted through the inner cheek soft tissue, parallel to the upper molars, and into the pterygomandibular space to block the nerve.
 
•
•How it works
•Closed-mouth technique: Unlike traditional mandibular blocks, this method does not require the patient to open their mouth widely, making it ideal for patients with trismus (limited jaw movement) or when a difficult airway is present.
 
•Injection site: The injection site is a fold of tissue between the maxillary tuberosity and the inner side of the mandibular ramus. The needle is inserted parallel to the occlusal plane of the upper teeth, in a similar location to a posterior superior alveolar (PSA) injection.
 
•Needle insertion: A long needle is inserted parallel to the occlusal plane and advanced 25–30 mm into the pterygomandibular space to deposit the anesthetic.
 
•Anesthetic effect: This injection anesthetizes all teeth in the quadrant on the injected side, including the gingival tissue from the third molar to the midline, as well as the lingual tissue and half of the tongue.
 
•Advantages
•Useful for limited mouth opening: It is the primary advantage and makes it suitable for patients with trismus, ankylosis, or a difficult airway.
 
•Less traumatic: It involves a less traumatic penetration of tissues compared to some other mandibular blocks.
 
•Lower complication rate: The risk of intravascular penetration is lower than with some other techniques.
 
•Faster onset of anesthesia: The anesthetic may take effect more rapidly.
 
•Disadvantages
•Requires practice: It can be difficult to master and is best learned through hands-on instruction.
•Longer onset time: Onset can sometimes be slower than other techniques.
•Volume of anesthetic: In some cases, a larger volume of anesthetic may be needed, potentially requiring a second injection.
 

122. How it works
Closed-mouth technique:
Unlike traditional mandibular
blocks, this method does not
require the patient to open
their mouth widely, making it
ideal for patients with trismus
(limited jaw movement) or
when a difficult airway is
present.
 

123. •Injection site: The injection site is a fold of tissue between the maxillary tuberosity and the inner side of the mandibular ramus. The
needle is inserted parallel to the occlusal plane of the upper teeth, in a similar location to a posterior superior alveolar (PSA) injection.
 
•Needle insertion: A long needle is inserted parallel to the occlusal plane and advanced 25–30 mm into the pterygomandibular space to
deposit the anesthetic.
 
•Anesthetic effect: This injection anesthetizes all teeth in the quadrant on the injected side, including the gingival tissue from the third
molar to the midline, as well as the lingual tissue and half of the tongue.
 
•Advantages
•• • Useful for limited mouth opening: It is the primary advantage and makes it suitable for patients with trismus, ankylosis, or a difficult
airway.
 

125. •Advantages
•Useful for limited mouth opening: It is the primary
advantage and makes it suitable for patients with
trismus, ankylosis, or a difficult airway.
 
•Less traumatic: It involves a less traumatic
penetration of tissues compared to some other
mandibular blocks.
 
•Lower complication rate: The risk

126. •Lower complication rate: The risk of
intravascular penetration is lower than with
some other techniques.
 
•Faster onset of anesthesia: The anesthetic may
take effect more rapidly.
 
•Disadvantages
•Requires practice: It can be difficult to master
and is best learned through hands-on
instruction.
•Longer onset time: Onset can sometimes be
slower than other techniques.