1. The document discusses various techniques for administering local anesthesia, including infiltration, nerve blocks, and intraosseous injections. 2. It describes in detail the inferior alveolar nerve block and Gow-Gates techniques, including proper patient positioning, needle placement, and structures anesthetized. 3. Factors that influence diffusion of local anesthetic solutions and barriers that can slow anesthesia are examined, along with tips for minimizing pain during injection.

1. 1
Chapter 4
Dr/Atef fouda
Prof. Oral & Maxillofacial Surgery
Cairo University
Egypt
Method of L.A
administration
 “Techniques”.

2. Atef A. Fouda.
Prof of Oral & Maxillofacial Surgery
Cairo University

3. Method of L.A administration
 “Techniques”.

4. Induction of L.A.
• Diffusion:
Depend on concentration of L.A. The amount should be related to
the SIZE of the nerve to be anesthetized and its SITE.
Type of nerve example Amount of anesthesia needed
Terminal branches Mucosa of palate 0.2ml
Small branches block Long buccal 0.6 ml
Large branches block Inferior alveolar 1.2 ml
Main nerve trunk mandibular 3.0 ml

5. Rate of diffusion
• Concentration gradient.
Initial conc.
Diffusion.
L.A.
L.A.
L.A.
Mantle
fibres
Core
fibres

6. Mantle fibres
(peripheral)
Molar region
Core fibres
(central)
Anterior region
incisors
Barriers slowing down complete nerve
anesthesia

7. perineurium
fasciculi
perilemma
epineurium
Epineural sheath
Endoneurium
Nerve membraneNerve barriers:
Barriers in the injection site
Some types of anesthetic technique
require penetration of other
structures to reach nerve tissues as
bone penetration

8. Infiltration anesthesia
Nerve block anesthesia
Main Nerve
trunk , its big
divisions or
large branches
Terminal branches
mostly unnamed

9. Infiltration anesthesia Nerve block anesthesia
Small terminal branches Large Nerve branches or nerve trunk
Small area anesthetized Large area anesthetized
Short duration Longer duration
Proper haemostasis Vasoconstriction away from the field
Safe With some risk
More anesthetic solution Mostly require Less anesthetic solution.
Rapid onset Prolonged onset
High success rate < 98% Less success rate > 85%
Easy to perform Need skill

10. Infiltration anesthesia

11. Most of terminal nerve
endings that supply the pulp
of teeth with their investing
structures are located inside
the jaw bone.
The deposited anesthetic
solution should reach the
terminal nerve endings to
do its anesthetic effect.

12. The buccal cortical
plate of bone has
small pores that
permit diffusion of
anesthetic solution
from outside to inside
the bone
Buccal
side
Multiple Bone Pores

13. Bone porosity found only
in maxilla and anterior
region of the mandible.
Mandibular bone porosity
decrease by age.

14. Diagnosis confirmation.
Medical history
Determination of anesthetic type.

15. Needle: Short needle 20 mm/ 27 G
Syringe: Any type
Adjust patient position
Take your position
Patient draping
Dental unite preparation

16. Back rest 45 degree with the floor.
Head rest & backrest on one line.
Maxilla level near to the shoulder.
8 o’clock position
Operator position.Patient position.

17. Insert the needle.
Retract tissue [cheek , lip or tongue]using mirror.
Dry the tissue in the future site of injection.
Apply antiseptic to the area.
Apply topical anesthetic.
Wait for 2 minutes.
Proper syringe handling.
Communicate with the patient.
Make tissue taut by retraction.
Make syringe out of the patient’s line of sight

18. Vertical:
2 mm. Above tooth root apex
Horizontal:
Mid point of tooth bisecting line
Bevel of the needle:
45 degree with long axis of tooth.
Facing bone.
2mm

19. Submucosal. Sub-periosteal.
Periosteum
Bevel Facing mucosa Bevel Facing bone
Less than 45 degree
Bevel Facing bone
45 degree
Paraperiosteal.

20. Deposit 1.5 ml of solution slowly.
Withdraw the needle.
Waite for 2 minutes.
Perform palatal injection if needed.

21. Palatal
side
Buccal
side
Multiple Bone PoresAbsence of Bone Porosity

22. Point of injection:
Mid way between gingival margin and
median palatine raphe.
Direction of the bevel:
Non significant.
Direction of the needle:
From other side.
There are some exceptions:
Last molar at the same point of second molar.
Central incisor at the incisive papillae.

23. Deposit 0.3 ml of solution slowly.
Withdraw the needle.
Perform your procedure.

25. Back rest 5 degree with the floor.
Head rest & backrest on one line.
Mandible at the level of elbow.
8 o’clock position for labial
Operator position.Patient position.
11 o’clock position for lingual

26. Vertical:
2 mm. below tooth root apex
Horizontal:
Mid point of tooth bisecting line
Bevel of the needle:
45 degree with long axis of tooth.
Facing bone. 2mm

27. Deposit 1.5 ml of solution slowly.
Withdraw the needle.
Waite for 2 minutes.
Perform lingual injection if needed.

28. Lingual
side
Labial
side
Multiple Bone PoresAbsence of Bone Porosity

29. Point of injection:
Lingual mucosa.
Direction of the bevel:
Non significant.
Direction of the needle:
From operator side.

30. Deposit 0.3 ml of solution slowly.
Withdraw the needle.
Perform your procedure.

32. Most of nerve block
techniques performed on
main nerve trunk or its large
branches.
The deposited anesthetic
solution should be near
the required nerve.

33. Inferior alveolar – lingual nerve block

34. The area that couldn’t be anesthetized with infiltration
anesthesia.
Longer procedure.
Multiple teeth procedure [large area].
Infection [acidic media] at the site of infiltration
anesthesia.
Indications:

35. Molars and premolars.
[pulp + investing st].
Structures supplied with
Inferior alveolar nerve and its branches.
Inferior alveolar + Mental N. + Incisive N.
Buccal mucoperiosteum.
Labial mucoperiosteum.
Skin, mucosa of lower lip.
Anterior teeth.
[pulp + investing st].
8 7 6 5 4 321

36. Soft tissue.
Molars and premolars.
[pulp + investing st].
Anterior teeth.
[pulp + investing st].
Buccal mucoperiosteum[premolars].
Labial mucoperiosteum.[anteriors]
Skin, mucosa of lower lip.
Hard structures

37. Lingual
mucoperiosteum of
same side teeth.
Half of the same
side tongue.
Half of the same
side mouth floor.

38. Diagnosis confirmation.
Medical history
Determination of anesthetic type.
Needle: Long needle 32-36 mm/ 25 G.
Bevel direction: non significant.
Syringe: Aspirating syringe
Adjust patient position
Take your position
Patient draping
Dental unite preparation

39. Back rest 5 degree with the floor.
Head rest & backrest on one line.
Mandible at the level of elbow.
Patient position.

40. 8 o’clock position.
Lt side injection Rt side injection
8 o’clock position.
Cross hand technique
10 o’clock position.
Behind technique.

41. 1-Coronoid notch imaginary line

43. Lingual nerve antero-medial to the inferior alveolar nerve
MedialLateral
Anterior
Posterior

44. 2-Syringe from other side at the premolar region

46. 3-Needle ½ cm from bisecting finger .
½ cm
½ cm

47. Pterygo-mandibular raphe
4-Needle should be lateral to the raphe
Medial Lateral
Anterior
PosteriorPterygo-mandibular raphe

48. 5- Needle should
touch bone at distance
about 25 mm from
surface mucosa.
[ 2/3 of the long
needle “36mm”inside
tissue].

49. 5-Needle should touch bone at distance about
25 mm from surface mucosa.
2-Syringe from other side at the premolar region.
3-Needle ½ cm bisecting finger nail.
1-Coronoid notch imaginary line.
4-Needle should be lateral to the raphe

50. The mandibular ramus
vary in angulations
from patient to
another, furthermore
may differ from side to
side.

51. In case of diverged ramus the barrel of the
syringe should be above molar region.
The needle touches bone at a longer distance than
usual “late touch” [ e.g:30 mm] = diverged rmus.

52. In case of converged ramus the barrel of the
syringe should be above anterior region.
The needle touches bone at a shorter distance than
usual “ early touch”[ e.g:15 mm] = converged ramus.

53. Deposit 1 ml of anesthetic solution at the site of
inferior alveolar nerve.
Withdraw needle about its half the distance [ 25/2 = 12.5
mm.] And inject 0.5 ml of anesthetic solution for lingual
nerve.
Withdraw the needle out side the tissues.

54. Buccal mucoperiosteum of molar region supplied with
long buccal nerve.
To anesthetize the long buccal nerve submucosal injection
Of 0.3 ml of the anesthetic solution is required to be
deposited opposite the intended tooth.

55. Wait for 10-15 for deep anesthesia.
Start your procedure after anesthesia
confirmation.

56. Structures pierced by needle during IANB
Mucosa
Buccinator muscle.
Buccal bad of fat.
Loose areolar C.T
Distribution of anesthetic solution during IANB
1 ml for inferior alveolar nerve.
0.5 for lingual nerve.
0.3 long buccal nerve [molars].
or cutaneous coli nerve [premolars].

57. Mental & incisive nerve blocks
Injecting of anesthetic solution at the
mental foramen will anesthetizes the
terminal branches of inferior alveolar
nerve “mental nerve and incisive nerve”.
The point of needle insertion is buccal and behind the
foramen. Needle advanced 4-6 mm and should touch
bone.
After aspiration deposit 0.6 ml of anesthetic solution and
massage the area after injection to force the anesthetic
solution to pass through the foramen.

58. Mental & incisive nerve blocks
The structures anesthetized :
1-The labial mucoperiosteum of anterior
teeth.[mental]
2-Buccal mucoperiosteum of premolars.[mental]
3-Skin and mucosa of lower lip.[mental]
4-The pulp and investing structures of anterior
teeth.[incisive]
5-The pulp and investing structures of premolars
[inferior alv.]

59. Long buccal nerve block.
Locate the retro molar triangle a the
area buccal and distal to the lower last
molar.
Insert the needle tip sub mucosally
and inject 0.6 ml of anesthetic
solution.
Structures anesthetized:
Buccal mucoperiosteum of mandibular
molars.

60. Gow-Gates technique.
“open mouth mandibular nerve block”.

61. Inferior alveolar –lingual nerve
block
Gow-Gates –mandibular nerve
block.
Success rate 80-85% Success rate > 95%
Positive aspiration 10-15% Positive aspiration 2%
Accessory innervations to teeth
pulps require separate injection.
Anesthetized with the
technique.
Duration about 4 hours Longer duration.
Supplementary long buccal
required
Only in few cases.
Trismus post op complication. null
Anatomical deviations require
technique modifications.
Non significant.

62. Technique of Gow-Gates anesthesia
The area that couldn’t be anesthetized with IANB.
Longer procedure.
Multiple teeth procedure [large area].
Infection [acidic media] at the site of IANB anesthesia.
Indications:

63. Molars and premolars.
[pulp + investing st].
Structures supplied with Inferior alveolar nerve and its branches.
Inferior alveolar + Mental N. + Incisive N.
Buccal mucoperiosteum.
Labial mucoperiosteum.
Skin, mucosa of lower lip.
Anterior teeth.
[pulp + investing st].
8 7 6 5 4 321
Structures supplied with lingual nerve .
Structures supplied with long buccal nerve [75%] .
Structures supplied with nerve to mylohyoid nerve .

64. Buccal mucoperiosteum.
Labial mucoperiosteum.
Skin, mucosa of cheek and
lower lip.
Tongue, floor of the mouth and
lingual mucosa of same side
Hard structures
ALL Teeth with their supporting
structures.
Soft tissue.

65. The same as IANB

66. IA nerve
Mylohyoid nerve
Lingual nerve
Long buccal nerve
Gow-Gates

67. 1-Distance of 10 mm above coronoid notch.

68. 2-Needle below mesio-palatal cusp of maxillary second molar.
6
8

69. 3-Imaginary Line from tragus of the ear to the corner of the mouth.

70. 4-Needle below mesio-palatal cusp of
maxillary second molar.
3-Distance of 10 mm above coronoid notch.
1-Mouth widely opened.
5-Imaginary Line from tragus of the
ear to the corner of the mouth.
6-Needle should touch bone “head
of the condyle” [about 25 mm
inside tissue].
2-Syringe above mandibular premolars.

71. Deposit 1.8 ml of anesthetic solution.
Withdraw the needle.
Patient asked to maintain his mouth opened for one minute
after injection.
Wait for 10-15 minutes before operation to ensure profound
deep anesthesia.

73. 1-Anterior superior alveolar N.B.
2-Middle superior alveolar N.B.
3-Posterior superior alveolar N.B.
4-Nasopalatine[incisive canal] N.B.
5-Greater palatine N.B.
Infra-orbital
nerve block

74. fix your index finger on the infra-orbital notch
and use your thumb to retract upper lip.
Insert needle 4 mm. lateral to the mucobuccal
fold until touch bone.
Inject 1ml of anesthetic solution after negative
aspiration followed by proper massage.
Infra-orbital NB

75. Structures anesthetized by anterior , middle
superior alveolar nerve block.
Soft tissue structures hard tissue structures
Pulp & investing structures
[ anteriors, premolars and MB root of
upper first molar]
Labial mucoperiosteum.
Buccal mucoperiosteum
[ premolars & MB root of upper first molar].
Upper lip skin & mucosa.
Skin of nose & lower eye lid.

76. 3-Posterior superior alveolar N.B.
Retract cheek opposite to the last upper
molar tooth.
Adjust needle to be 45 degree with the
sagittal plane.
At the area of maxillary tuberosity and
above the level of last molar root apices.
inject 1 ml of anesthetic solution after
bone is touched and negative aspiration.
Structures anesthetized:
Pulp, Investing structures and buccal
muco-periosteum of upper molar teeth
except MB root and related
mucoperiosteum.
45

77. 4-Nasopalatine [incisive canal] N.B.
Naso palatine nerves of both sides of the maxillary
anterior region could be anesthetized through injection
of palatine papilla.
Lateral injection of palatine papilla with 0.5 ml after
negative aspiration.

78. 4-Nasopalatine [incisive canal] N.B.
palatal mucoperiosteum of upper centrals and
lateral incisors teeth.
Partial mucoperiosteum of upper canines.
Structures anesthetized

79. 5-Greater palatine N.B.
greater palatine main nerve go out through the greater
palatine foramen which located 1 cm from the gingival
margin distal to the second molar.
Injection of 0.6 ml after negative aspiration.

81. Intra-pulpal anesthesia

82. Intra-ligamentary anesthesia PDL

83. Intra-osseous anesthesia

84. Intra-osseous
Intra-ligamentary
Intra-pulpal
Infiltration

85. How to achieve painless injection
Use fine needle gauge 25 or more.
Apply topical anesthetic two minutes before
injection.
Change needle after every three tissue
penetration.
Use Paraperiosteal injection which is less
painful than sub-periosteal.
Do not inject excess amount in palatal side.
deposit few drops before injection then while
the needle inside the tissue wait for a while
before injection to be completed.

86. Make tissues taut.
The cartridge should be brought to room
temperature.
Ask patient to receive analgesic two hours
before procedure.
Apply pressure on soft tissue structures
near injection site.
Syringe away from the sight of the patient.
Communicate with the patient.
Painless injection:

87. How to test anesthesia
Last structures to be anesthetized is the best to test
Golden rules:
Site of test should be not harm tissues.
Site of test should represent nerve to be tested.
Objective test is better than subjective one.

88. How to test anesthesia
Last structures to be anesthetized is the best to test
Golden rules:

89. Initial conc.
Diffusion.
L.A.
L.A.
L.A.
Mantle
fibres
Core
fibres
Last structures to be anesthetized is the best to test

90. Site of test should be not harm tissues.
Test should be done in area of future procedure
Use of least destructive tools for testing tissues

91. Tests of anesthesia
Intra-osseous
Intra-ligamentary
Intra-pulpal
Infiltration
Site of test should represent nerve to be tested.

92. Objective test is better than subjective one.
Tests of anesthesia
Use of reliable tools is much better than
depending on patient feelings.

93. Subjective test:
depend on patient description.
Patient tell about numbness.
Numbness in mucosa or skin covering muscular structures.
Disappearance of pre-anesthetic pain.
Tests of anesthesia

94. How to test anesthesia
Objective test
performed by operator.
Use of tool to stimulate pain.
explorer
Pulp tester

95. Site of examination according to nerve supply:
Infiltration anesthesia:[PL of tooth and palatal or lingual mucosa]
Inf. Alv. N: [Periodontal ligament of all mandibular teeth]
Lingual N [lingual mucosa of all lower teeth].
Long buccal N [buccal mucosa of lower molar region]
Anterior Sup Alv [call upper anterior teeth]
Middle sup Alv. [P.L. of premolars and MB root of first molar]
Posterior sup Alv. [P.L. of upper molars except MB root of 1st molar
Grater palatine [Palatal mucosa of premolars and molars]
Nasopalatine [Palatal mucosa of anterior teeth].
Test of anesthesia

96. Significance of test results:
Determine degree of anesthesia :
[evaluation of anesthesia]
Failed
anesthesia
Weak anesthesia
Deep anesthesia
Deep profound anesthesia

97. Significance of test results:
Deep profound anesthesia:
Pain and general sensation completely blocked.
Weak anesthesia:
Partial block of pain
Deep anesthesia:
Pain but not general sensation blocked.
failed anesthesia:
No block of pain

98. Causes of non profound anesthesia :
Improper injection site [depend on distance]
Improper technique
Insufficient anesthetic amount [depend on amount]
Intravascular injection [failure]
Inflammation at the injection site.[ depend on degree of inf]
Multiple needle penetration.
Presence of accessory innervations.[weak]
Anatomical variation.
Age changes.
Improper timing.

99. Q.Are multiple injections before start of
anesthesia preferable?
The local anesthetic solutions are slightly acidic and
increase in its amount in the field decreases the pH
of the media and delays the dissociation of the free
base form. In contrast multiple injections after start
of anesthesia potentiates its action and elongate the
duration of anesthesia.

100. 100
Local anesthetic Complications.
Chapter IV: