Contents
 Introduction
 Classification of cranial nerves
 Derivatives of pharyngeal arches
 Nuclei of trigeminal nerve
 Muscles of mastication
Origin, insertion, function, nerve supply,
blood supply
 Course and relation
 Distribution & Supply
 Branches (origin, course & distribution)
Main trunk
 Nervous spinosus
 Nerve to medial pterygoid
Anterior division
 Buccal nerve
 Masseteric nerve
 Deep temporal nerve
 Nerve to lateral pterygoid
Posterior division
 Auriculotemporal nerve
 Lingual nerve
 Inferior alveolar nerve
 Otic ganglion
 Anesthetic technique
Nerves anesthetized, area anesthetized,
indication, contraindication & technique
 Inferior alveolar nerve block
 Lingual nerve block
 Buccal nerve block
 Mental nerve block
 Incisive nerve block
 Gow gates technique
 Vazirani akinosi technique
 Supplimental injection technique
 Intrapulpal injection
 Periodontal injection
 Intraseptal injection
 Local complications
1. Needle breakage
2. Prolonged anesthesia or paresthesia
3. Facial nerve paralysis
4. Trismus
5. Soft tissue injury
6. Hematoma
7. Pain on injection
8. Burning on injection
9. Infections
10. Edema
11. Sloughing of tissue
12. Postanesthetic intraoral lesions
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 Systemic complications
1. Adverse drug reactions
2. Intravascular injection
3. Drug overdose
4. Allergy
 Clinical implication
 Motor examination
 Reffered pain
 Trigeminal neuralgia
 Jaw jerk reflex
 Anatomic variation
 Age changes
 Nerve injury
 Direct injury
 Lesion associated with anesthetic technique
 Effect of irrigants
 Effect of sealer
 Effect of obturating material
 Lesion associated with implant surgery
 Lesion associated with third molar removal
 Effect of mandibular fracture
 Conclusion
 References
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 Mandibular nerve is largest
branch of trigeminal nerve.
 It is nerve of first branchial
arch.
Derivatives of branchial arches
Distribution & supply
Meningeal branch
• ORIGIN
• COURSE
• SUPPLY
Nerve to medial pterygoid & lateral
pterygoid
• Origin
• Course
• Motor
branches to
otic ganglion
Medial pterygoid
Origin • Tuberosity of maxilla
• Medial surface of
lateral pterygoid plate
Insertion Inner surface of angle of
mandible
Action Elevation & protrusion
NERVE SUPPLY Nerve to medial pterygoid
BLOOD
SUPPLY
Facial & maxillary artery
Lateral pterygoid
Origin • Upper head from crest of
greater wing of sphenoid
• Lower head from lateral
surface of lateral
pterygoid plate
Insertion Pterygoid fovea,
Ant. Margin of articular disk
Action Depress & protrude the
mandible
NERVE SUPPLY Nerve to lateral pterygoid
BLOOD SUPPLY Muscular branch of maxillary
artery
Buccal nerve
• Only sensory
branch of anterior
devision
• Course through
lateral pterygoid
• Supply: skin,
mucous
membrane,
buccinators, gums
of premolar &
molar
Masseteric nerve
 Origin – upper
border of lateral
pterygoid, front of
TMJ
 Course – runs
laterally
 Enters deep
surface of
masseter
Masseter
Origin Anterior 2/3rd of lower
border of zygomatic arch
Insertion Ramus of mandible
Action Elevates the mandible
NERVE SUPPLY Masseteric nerve
BLOOD SUPPLY Transverse facial artery
Deep temporal nerve
Anterior &
posterior part
Runs between
lat. Pterygoid
& skull
Supply -
temporalis
TEMPORALIS
Origin Temporal fossa & fascia
Insertion Coronoid process & ant.
Border of ramus
Action Elevate the mandible
NERVE SUPPLY Deep temporal nerve
BLOOD SUPPLY Superficial temporal & deep
temporal arteries
Auriculotemporal nerve
 2 roots encircles
middle meningeal
artery.
 Course – runs between
neck of mandible &
sphenomandibular
ligament
 Behind the mandible it
ascends upwards.
 Auricular part – tragus,
pinna, internal acoustic
meatus, tympanic
membrane
 Temporal part – skin of
temple.
Lingual nerve
 Course – begins 1 cm below
skull.
 2cm below joins chorda
tympani.
 Relations – runs downward &
forward
 Finally it lies on Hyoglossus &
genioglossus
Relation with chorda tympani
Relation with mylohyoid and superior constrictor
Relation with submandibular duct
• Runs vertically
downwards , enters
mandibular canal.
• Branches
1. Mylohyoid branch
2. Branches to lower
teeth
3. Mental nerve
4. Incisive nerve
Otic ganglion
 Peripheral parasympathetic
ganglion
 Topographically –
mandibular nerve
 Functionally –
glossopharyngeal nerve
 Size & situation – 2-3 mm,
infratemporal fossa
Parasympathetic supply
Parotid gland
Saliva secretion pathway
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Sympathetic root
From plexus on middle meningeal artery
Contains post ganglionic fibers from
superior cervical ganglion
No relay
Auriculotemporal nerve
Parotid gland
Sensory root
 From Auriculotemporal nerve
 Other fibers are –
 Nerve to medial pterygoid
 Chorda tympani
 Nerve to pterygoid canal
Anesthetic techniques
[A] Inferior alveolar nerve block
 Nerve anesthetized : IA, lingual, mental, incisive.
 Area anesthetized : mandibular teeth till midline, buccal
mucoperiosteum, ant. 1/3rd of tongue & floor of mouth.
 Indication : multiple extraction, buccal soft tissue
anesthesia.
 Contraindication: acute infection, allergic, very young
child.
 Advantage: wide area of anesthesia
 Disadvantage: high rate of in adequate anesthesia, self
inflicted soft tissue trauma.
Technique (Malamed)
 Area of insertion : medial side of ramus
 Orientation of needle : bevel facing towards
bone
 Position of clinician : 8 o'clock & 10 o’clock
 Height of injection : 6-10 mm above
occlusal plane. Changes with age.
 Anteroposterior site of injection : 3/4th
width of ramus
 Depth of penetration : 20-25mm. Contact
the bone.
 Aspirate in 2 planes & deposit 1.5ml over 60
sec.
 Slowly withdraw the needle till half
length remain inside & deposit 0.2ml
to anesthetize lingual nerve.
 Subjective symptoms : numbness of
lower lip & tongue
 Objective symptoms : no response to
EPT & no pain during procedure.
 Precautions : don’t deposit if bone is
not contacted.
 Failure of anesthesia : deposited to
far anteriorly, posteriorly, bifid
canal.
[B] Lingual nerve block
[C] Buccal nerve block
Landmark : mandibular
molar, mucobuccal fold.
Operator position : 8
o’clock & 10 o’clock
Penetrate 2-4 mm bevel
facing downwards.
If aspiration is –ve
deposit 0.3ml/10sec
[D] Mental nerve block
 Area anesthetized : buccal mucous membrane ant to
mental foramen, lower lip
Technique :
 Locate mental foramen
 Insert at mucobuccal fold ant to mental foramen
 Target area : between apices of first & second
Premolar
 Depth of penetration 5-6 mm
If aspiration is –ve deposit 0.6ml over 20 sec
 Procedure for incisive nerve block is similar to
Mental nerve block.
[E] Gow gates technique (1973)
Nerve anesthetized
 Inferior alveolar
 Mental
 Incisive
 Lingual
 Mylohyoid
 Auriculotemporal
 Long buccal (in 75% of the cases)
 Area anesthetized :
 Mandibular teeth to midline
 Buccal mucoperiosteum
 Ant 2/3rd of the tongue
 Floor of the mouth
 Skin over the zygoma
 Posterior portion of temporal region
 Contraindications
 Acute inflammation
 Young children & mentally
handicapped adults
 Patient who is unable to open their
mouth
 Extra oral landmarks
 lower border of tragus
 Corner of the mouth
 Intraoral landmark
 Mesiolingual cusp of maxillary second molar
 Technique
 Ask the patient to extend his neck and to open wide
 Direct the needle from opposite corner of mouth at
lower premolar area parallel to extra oral landmark.
 When maxillary third molar is present site of
penetration will be distal to it.
 Advance the needle until condylar neck is contacted
 Depth of penetration – 25mm
 Deposit 1.8ml (original 3ml)
[F] Vazirani Akinosi closed mouth
technique (1977)
 Synonyms :
 Akinosi technique
 Closed mouth Mandibular nerve block
 Tuberosity technique
 Indications
 Limited mandibular opening
 Inability to visualize landmarks for IANB
 Nerve anesthetized
 IAN, incisive, mental, lingual, mylohyoid
Landmark
 Mucogingival junction
 Maxillary tuberosity
 Coronoid notch
Area of insertion
 Soft tissue at the medial border of
mandibular ramus. Directly adjacent to
maxillary tuberosity.
 At the height of mucogingival junction
adjacent to max third molar.
Target area
 Soft tissue on the medial border of
ramus as the mandibular nerve comes
out from foramen ovale.
 Orientation of bevel : away from ramus
 Ask the patient to occlude gently
 Advance the needle parallel to maxillary occlusal plane
 Depth of penetration- 25mm
 Deposit 1.5- 1.8ml over 60 secs
 After injection make the patient upright or semiupright
position.
Extraoral technique
Supplemental injection technique
1. Intrapulpal injection
2. Periodontal injection
3. Intraseptal injection
4. Mandibular infiltration
Intrapulpal injection
 Indication
 When pain control is necessary for pulp extirpation
 In absence of adequate anesthesia from other technique
 Contraindication : NONE
 Technique
 Wedge the needle firmly into the pulp chamber
 Bend the needle if necessary
 Deposit 0.2-0.3 ml
Periodontal injection
 Indications
1. Single tooth anesthesia
2. Rx of isolated teeth in both quadrants
3. Treatment of children
4. Where nerve block is contraindicated
(hemophiliac)
5. In diagnosis of mandibular pain
 Contraindication
1. Inflammation
2. Presence of primary teeth
Peripress
 Advantages
 No soft tissue anesthesia
 Minimum dose
 Alternative to partially successful block
 Rapid onset of profound anesthesia
 Less traumatic
 Disadvantage
 Proper needle placement is difficult
 Excessive pressure may break the glass cartridge
 Chances of tooth extrusion
 Technique
 Area of insertion : Long axis of the tooth to be treated
on its mesial or distal root.
 If interproximal contacts are tight direct from the
lingual or buccal surface
 Target area : depth of gingival sulcus
 Face the bevel toward the tooth
 Insert and deposit 0.2ml over 20 sec.
Intraseptal injection
 Technique
 Area of insertion – center of
interdental papilla
 Stabilize the syringe & inject 0.2ml
over 20 sec
Fischer 1,2,3 technique
 Local complications
1. Needle breakage
2. Prolonged anesthesia or paresthesia
3. Facial nerve paralysis
4. Trismus
5. Soft tissue injury
6. Hematoma
7. Pain on injection
8. Burning on injection
9. Infections
10. Edema
11. Sloughing of tissue
12. Postanesthetic intraoral lesions
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 Systemic complications
1. Adverse drug reactions
2. Intravascular injection
3. Drug overdose
4. Allergy
 Clinical implication
 Motor examination
 Reffered pain
 Trigeminal neuralgia
 Jaw jerk reflex
 Anatomic variation
 Age changes
 Nerve injury
 Direct injury
 Lesion associated with anesthetic technique
 Effect of irrigants
 Effect of sealer
 Effect of obturating material
 Lesion associated with implant surgery
 Lesion associated with third molar removal
 Effect of mandibular fracture
 Conclusion
 References
Needle breakage
 Occures at the hub
 Causes
 Intentional bending
 Sudden unexpected movement of patient
 Forceful contact with bone
 Management
 Refer to oral surgeon
 Locate the fragment
 Remove under anesthesia
 Prevention
 Don’t use short or 30 gauge needle
 Do not insert to its hub
 Do not bend
Prolong anesthesia or paresthesia
 Persistent anesthesia or altered sensation beyond the
expected duration
 Causes
 Trauma to the nerve
 Contamination with alcohol
 Insertion of needle into foramen
 Hemorrhage around neural sheath
 Problems
 Self inflicted injury
 Hyperesthesia
 Management
 Resolve within 8weks
 Tincture of time
Facial nerve paralysis
 Cause
 Introduction of LA into the
capsule of parotid gland
 Over insertion of needle
 Problems : unilateral paralysis of
face
 Management
 Contact lenses should be
removed
 Eye patch applied
Trismus
 It is prolonged tetanic spasm of the jaw muscles by
which normal opening of the muscle is restricted
 Causes
 Trauma to muscles or blood vessel
 Contaminated solution
 Management
 Heat therapy
 Analgesics
 Muscle relaxants (diazepam)
Soft tissue injury
 Seen in younger children, disabled children
 Management
 Analgesics
 Lukewarm saline rinse for swelling
 Antibiotics
 Lubricants application
Hematoma
 Localized collection of extravasated blood.
 Cause : injection into vessels
 Management
 Direct pressure application
 Don’t apply heat.it worsen the situation.
 Cold pack
Burning on
injection
 Cause
 Acidic pH of the solution
 Rapid injection
 Contamination
 Management
 Buffering the LA
 Slowing the speed
Infection
 Cause
 Contamination of
needle before
injection
 Prevention
 Avoid contamination
 Management
 Antibiotic
 analgesic
Edema
 Causes
 Trauma during injection
 Infection
 Allergy
 Hemorrhage
 Problem
 Airway obstruction
 Management
 Resolve on its own
 If produced by infection antibiotic is given
 Histamine blocker
 Lidocaine 4.4 mg/kg
 With Adrenalin 7mg/kg
Drug overdose
Cardivascular effect CNS effect
1.8-5 anti dysarythmic action 4.5-7 cns depression
5-10 ecg alteration 7.5-10 tonic clonic
>10 cardiac arrest >10generalized cns depression
Minimal to moderate overdose levels
 Talkativeness, apprehension, excitability
 Slurred speech, euphoria, nystagmus, sweating, vomiting
 Disorientations, loss of response to painful stimuli
 elevated blood pressure, heart rate
Moderate to high overdose levels
 Tonic clonic seizure followed by CNS depression
Allergy
1. Early phase: skin reactions
 Pruritus, erythema, urticaria, nausea, vomiting
 Inflammation of nose & mucous membrane
2. Gastrointestinal & genitourinary disturbances
 Abdominal cramp, diarrhea
 Fecal & urinary inconsistence
3. CVS symptoms
 Pallor, palpitation, tachycardia
PRURITUS
URTICARIA
Clinical implications
Motor examination of mandibular nerve
 For temporalis muscle – hollowing out of
temporal fossa
 For masseter – clenching of jaw
 Tensor tympani – hyperacusis
 Pterygoid – sidewise movement of jaw
video
Referred pain
Cancer of tongue
Effect on lingual &
Auriculotemporal
nerve
Pain radiate to
ear & temporal
fossa
Rx – sectioning of
lingual nerve
Jaw jerk reflex
 Both afferent & efferent path
supplied by mandibular nerve
 Tapping of chin causes
contraction of masseter
muscle.
 Unilateral lesion cause
depression of reflex
 Bilateral supranuclear lesion
causes accentuated response.
Trigeminal neuralgia
 Synonym – TIC DOLOUREUX (Nicholas
Andre,1756) ,prosoplegia.
 Peripheral disease affecting sensory root.
 Sudden attack of severe pain.
 Etiology : usually idiopathic, demyelination,
petrous ridge compression, intracranial tumor.
Clinical features
 Unilateral, short, stabbing severe pain.
 F > M
 Right > left
 Don’t occur during sleep.
 TRIGGER ZONE
Central
portion
of face
Nasolabial
fold
Lip,
periorbital
area
tongue
Differential diagnosis
 Migraine
 Sinusitis
 Dental pain
 Trotters syndrome
Management
Medical
• carbamazepine
• Gabapentin
• Baclofen
• Sodium valporate
Surgical
• Glycerol injection
• Microvascular
decompression
• Percutaneous
rhizotomy
• Gamma knife
radiosurgery
Anatomic variations
 Bifid mandibular nerve
 Trifid mandibular nerve
 Accessory mandibular foramen
 Accessory mylohyoid nerve
 Retromolar foramen
 Contralateral innervation of anterior teeth
 Various shape of canal – round, tear drop &
dumbbell shape
Bifid mandibular canal
Prevalence = 0.5-0.9%
ajith A et al ’05
Accessory mandibular foramen
Retromolar foramen
Age changes
 Degeneration
 Decrease number
of myelinated
fiber
Nerve injury
Direct injury
1. Lesion associated with anesthetic
technique
 Due to direct injury with
needle- lingual nerve
 Due to anesthetic solution-
articaine
 Anxious patient,
unexpected movement
2.Lesion related to Endodontic
procedure
A. Position of tooth
B. By periapical infection
C. By biomechanical preparation
D. By irrigating solution
E. By root canal sealer
F. By gutta percha
Proximity of root apex
 The proximity of the roots of the 2nd premolars and 1st
and 2nd molars
 Causes paresthesia
 to avoid techniques of hot condensation
 Use of MTA sealed apex
4 possible types of factors that can cause tissue damage and
lead to develop symptoms:
1. Chemical factors because of the neurotoxic effects of
sealer or irrigating solutions.
2. Mechanical trauma from over-instrumentation
3. A pressure phenomenon from the presence of core filling
material or sealer within the inferior alveolar canal
4. Overheating of tissues because of incorrect warm
condensation techniques
(Nikolaos et al,2017)
Effect of Biomechanical
Preparation & Obturation
 Direct damage during BMP
 Reversible and irreversible blockage of
nerve conduction or by alteration of the
nerve membrane potential
 Disruption of apical constriction
 Repair by scarring
Irrigation
 Hypochlorite accident
 When apical foramina has been destroyed
 Extreme pressure
 Binding of the needle
Root canal sealer
Factors increase the risk of sealer extrusion
 Over-instrumentation
 The complexity of the anatomy of the root canal system,
 Excessive amount of sealer,
 Excessive compaction force,
 Hydrostatic pressure,
 The use of lentulo spirals,
 Immature canal apices or root tip
resorption
 Experimental studies have shown that sealers which
contain both eugenol and paraformaldehyde were the
most toxic
 could inhibit conduction of the action potential of the
nerves
 Paraformaldehyde is a potent neurotoxin and may cause
chemical destruction of the nerve axon because of its
gaseous nature
 Brodin et al. reported that Endomethasone can
irreversibly inhibit the conduction in the rat phrenic
nerve.
3. Lesion due to dental implant
surgery
 Due to inadequate radiological & clinical diagnosis
 Recklessness of clinicians
 Length of implant
4. Lesion related to third molar
removal surgery
 Due to inexperienced clinician
 Loss of integrity of cortical bone
of inferior alveolar canal.
 Proximity of the canal with
tooth.
 When path of lingual nerve is in
retromolar pad area
Preventive method
 Coronectomy
 Wang et al. proposed the use of orthodontic
traction
 Tolstunov et al. proposed pericoronal osteotomy
a) Coronectomy
b) orthodontic traction
c) Pericoronal osteotomy
5. Mandibular fractures
 In a study conducted by Bede et al. found that
linear displacement and comminuted fractures
caused more nerve lesions
 longer period of recovery.
 Recovery of nerve function in 91% of cases was
obtained
Prevalence
Treatment of nerve lesion
 Administration of
vitamin B12
 Microsurgery
Conclusion
 Mandibular nerve is principal nerve supply of
mandible.
 As an endodontist we should have thorough
knowledge of distribution.
 We should be careful while performing any
endodontic procedure, be it nerve block, BMP,
sealer application or obturation.
References
1. Gray’s anatomy – 3rd edition
2. Chaurasias human anatomy – 5th edition
3. Handbook of local anesthesia – Malamed 1st edition
4. Manual of local anesthesia in dentistry – AP Chitre
5. Atlas of human anatomy – Netter
6. Journal of endodontics
7. Pubmed
8. www.google.co.in
Mandibular nerve

Mandibular nerve

  • 2.
    Contents  Introduction  Classificationof cranial nerves  Derivatives of pharyngeal arches  Nuclei of trigeminal nerve  Muscles of mastication Origin, insertion, function, nerve supply, blood supply  Course and relation  Distribution & Supply
  • 3.
     Branches (origin,course & distribution) Main trunk  Nervous spinosus  Nerve to medial pterygoid Anterior division  Buccal nerve  Masseteric nerve  Deep temporal nerve  Nerve to lateral pterygoid Posterior division  Auriculotemporal nerve  Lingual nerve  Inferior alveolar nerve  Otic ganglion
  • 4.
     Anesthetic technique Nervesanesthetized, area anesthetized, indication, contraindication & technique  Inferior alveolar nerve block  Lingual nerve block  Buccal nerve block  Mental nerve block  Incisive nerve block  Gow gates technique  Vazirani akinosi technique  Supplimental injection technique  Intrapulpal injection  Periodontal injection  Intraseptal injection
  • 5.
     Local complications 1.Needle breakage 2. Prolonged anesthesia or paresthesia 3. Facial nerve paralysis 4. Trismus 5. Soft tissue injury 6. Hematoma 7. Pain on injection 8. Burning on injection 9. Infections 10. Edema 11. Sloughing of tissue 12. Postanesthetic intraoral lesions C o n t e n t s
  • 6.
     Systemic complications 1.Adverse drug reactions 2. Intravascular injection 3. Drug overdose 4. Allergy  Clinical implication  Motor examination  Reffered pain  Trigeminal neuralgia  Jaw jerk reflex  Anatomic variation  Age changes
  • 7.
     Nerve injury Direct injury  Lesion associated with anesthetic technique  Effect of irrigants  Effect of sealer  Effect of obturating material  Lesion associated with implant surgery  Lesion associated with third molar removal  Effect of mandibular fracture  Conclusion  References
  • 8.
  • 9.
    1  Mandibular nerveis largest branch of trigeminal nerve.  It is nerve of first branchial arch.
  • 10.
  • 13.
  • 14.
  • 15.
    Nerve to medialpterygoid & lateral pterygoid • Origin • Course • Motor branches to otic ganglion
  • 16.
    Medial pterygoid Origin •Tuberosity of maxilla • Medial surface of lateral pterygoid plate Insertion Inner surface of angle of mandible Action Elevation & protrusion NERVE SUPPLY Nerve to medial pterygoid BLOOD SUPPLY Facial & maxillary artery
  • 17.
    Lateral pterygoid Origin •Upper head from crest of greater wing of sphenoid • Lower head from lateral surface of lateral pterygoid plate Insertion Pterygoid fovea, Ant. Margin of articular disk Action Depress & protrude the mandible NERVE SUPPLY Nerve to lateral pterygoid BLOOD SUPPLY Muscular branch of maxillary artery
  • 20.
    Buccal nerve • Onlysensory branch of anterior devision • Course through lateral pterygoid • Supply: skin, mucous membrane, buccinators, gums of premolar & molar
  • 21.
    Masseteric nerve  Origin– upper border of lateral pterygoid, front of TMJ  Course – runs laterally  Enters deep surface of masseter
  • 22.
    Masseter Origin Anterior 2/3rdof lower border of zygomatic arch Insertion Ramus of mandible Action Elevates the mandible NERVE SUPPLY Masseteric nerve BLOOD SUPPLY Transverse facial artery
  • 24.
    Deep temporal nerve Anterior& posterior part Runs between lat. Pterygoid & skull Supply - temporalis
  • 25.
    TEMPORALIS Origin Temporal fossa& fascia Insertion Coronoid process & ant. Border of ramus Action Elevate the mandible NERVE SUPPLY Deep temporal nerve BLOOD SUPPLY Superficial temporal & deep temporal arteries
  • 27.
    Auriculotemporal nerve  2roots encircles middle meningeal artery.  Course – runs between neck of mandible & sphenomandibular ligament  Behind the mandible it ascends upwards.  Auricular part – tragus, pinna, internal acoustic meatus, tympanic membrane  Temporal part – skin of temple.
  • 28.
    Lingual nerve  Course– begins 1 cm below skull.  2cm below joins chorda tympani.  Relations – runs downward & forward  Finally it lies on Hyoglossus & genioglossus
  • 29.
  • 30.
    Relation with mylohyoidand superior constrictor
  • 31.
  • 32.
    • Runs vertically downwards, enters mandibular canal. • Branches 1. Mylohyoid branch 2. Branches to lower teeth 3. Mental nerve 4. Incisive nerve
  • 34.
    Otic ganglion  Peripheralparasympathetic ganglion  Topographically – mandibular nerve  Functionally – glossopharyngeal nerve  Size & situation – 2-3 mm, infratemporal fossa
  • 35.
  • 36.
  • 37.
    Sympathetic root From plexuson middle meningeal artery Contains post ganglionic fibers from superior cervical ganglion No relay Auriculotemporal nerve Parotid gland
  • 38.
    Sensory root  FromAuriculotemporal nerve  Other fibers are –  Nerve to medial pterygoid  Chorda tympani  Nerve to pterygoid canal
  • 39.
  • 41.
    [A] Inferior alveolarnerve block  Nerve anesthetized : IA, lingual, mental, incisive.  Area anesthetized : mandibular teeth till midline, buccal mucoperiosteum, ant. 1/3rd of tongue & floor of mouth.  Indication : multiple extraction, buccal soft tissue anesthesia.  Contraindication: acute infection, allergic, very young child.  Advantage: wide area of anesthesia  Disadvantage: high rate of in adequate anesthesia, self inflicted soft tissue trauma.
  • 43.
    Technique (Malamed)  Areaof insertion : medial side of ramus  Orientation of needle : bevel facing towards bone  Position of clinician : 8 o'clock & 10 o’clock  Height of injection : 6-10 mm above occlusal plane. Changes with age.  Anteroposterior site of injection : 3/4th width of ramus  Depth of penetration : 20-25mm. Contact the bone.  Aspirate in 2 planes & deposit 1.5ml over 60 sec.
  • 45.
     Slowly withdrawthe needle till half length remain inside & deposit 0.2ml to anesthetize lingual nerve.  Subjective symptoms : numbness of lower lip & tongue  Objective symptoms : no response to EPT & no pain during procedure.  Precautions : don’t deposit if bone is not contacted.  Failure of anesthesia : deposited to far anteriorly, posteriorly, bifid canal. [B] Lingual nerve block
  • 46.
    [C] Buccal nerveblock Landmark : mandibular molar, mucobuccal fold. Operator position : 8 o’clock & 10 o’clock Penetrate 2-4 mm bevel facing downwards. If aspiration is –ve deposit 0.3ml/10sec
  • 47.
    [D] Mental nerveblock  Area anesthetized : buccal mucous membrane ant to mental foramen, lower lip Technique :  Locate mental foramen  Insert at mucobuccal fold ant to mental foramen  Target area : between apices of first & second Premolar  Depth of penetration 5-6 mm If aspiration is –ve deposit 0.6ml over 20 sec  Procedure for incisive nerve block is similar to Mental nerve block.
  • 48.
    [E] Gow gatestechnique (1973) Nerve anesthetized  Inferior alveolar  Mental  Incisive  Lingual  Mylohyoid  Auriculotemporal  Long buccal (in 75% of the cases)
  • 49.
     Area anesthetized:  Mandibular teeth to midline  Buccal mucoperiosteum  Ant 2/3rd of the tongue  Floor of the mouth  Skin over the zygoma  Posterior portion of temporal region  Contraindications  Acute inflammation  Young children & mentally handicapped adults  Patient who is unable to open their mouth
  • 50.
     Extra orallandmarks  lower border of tragus  Corner of the mouth  Intraoral landmark  Mesiolingual cusp of maxillary second molar  Technique  Ask the patient to extend his neck and to open wide  Direct the needle from opposite corner of mouth at lower premolar area parallel to extra oral landmark.  When maxillary third molar is present site of penetration will be distal to it.  Advance the needle until condylar neck is contacted  Depth of penetration – 25mm  Deposit 1.8ml (original 3ml)
  • 53.
    [F] Vazirani Akinosiclosed mouth technique (1977)  Synonyms :  Akinosi technique  Closed mouth Mandibular nerve block  Tuberosity technique  Indications  Limited mandibular opening  Inability to visualize landmarks for IANB  Nerve anesthetized  IAN, incisive, mental, lingual, mylohyoid
  • 54.
    Landmark  Mucogingival junction Maxillary tuberosity  Coronoid notch Area of insertion  Soft tissue at the medial border of mandibular ramus. Directly adjacent to maxillary tuberosity.  At the height of mucogingival junction adjacent to max third molar. Target area  Soft tissue on the medial border of ramus as the mandibular nerve comes out from foramen ovale.
  • 55.
     Orientation ofbevel : away from ramus  Ask the patient to occlude gently  Advance the needle parallel to maxillary occlusal plane  Depth of penetration- 25mm  Deposit 1.5- 1.8ml over 60 secs  After injection make the patient upright or semiupright position.
  • 57.
  • 59.
    Supplemental injection technique 1.Intrapulpal injection 2. Periodontal injection 3. Intraseptal injection 4. Mandibular infiltration
  • 60.
    Intrapulpal injection  Indication When pain control is necessary for pulp extirpation  In absence of adequate anesthesia from other technique  Contraindication : NONE  Technique  Wedge the needle firmly into the pulp chamber  Bend the needle if necessary  Deposit 0.2-0.3 ml
  • 61.
    Periodontal injection  Indications 1.Single tooth anesthesia 2. Rx of isolated teeth in both quadrants 3. Treatment of children 4. Where nerve block is contraindicated (hemophiliac) 5. In diagnosis of mandibular pain  Contraindication 1. Inflammation 2. Presence of primary teeth Peripress
  • 62.
     Advantages  Nosoft tissue anesthesia  Minimum dose  Alternative to partially successful block  Rapid onset of profound anesthesia  Less traumatic  Disadvantage  Proper needle placement is difficult  Excessive pressure may break the glass cartridge  Chances of tooth extrusion
  • 63.
     Technique  Areaof insertion : Long axis of the tooth to be treated on its mesial or distal root.  If interproximal contacts are tight direct from the lingual or buccal surface  Target area : depth of gingival sulcus  Face the bevel toward the tooth  Insert and deposit 0.2ml over 20 sec.
  • 64.
    Intraseptal injection  Technique Area of insertion – center of interdental papilla  Stabilize the syringe & inject 0.2ml over 20 sec
  • 65.
  • 67.
     Local complications 1.Needle breakage 2. Prolonged anesthesia or paresthesia 3. Facial nerve paralysis 4. Trismus 5. Soft tissue injury 6. Hematoma 7. Pain on injection 8. Burning on injection 9. Infections 10. Edema 11. Sloughing of tissue 12. Postanesthetic intraoral lesions C o n t e n t s
  • 68.
     Systemic complications 1.Adverse drug reactions 2. Intravascular injection 3. Drug overdose 4. Allergy  Clinical implication  Motor examination  Reffered pain  Trigeminal neuralgia  Jaw jerk reflex  Anatomic variation  Age changes
  • 69.
     Nerve injury Direct injury  Lesion associated with anesthetic technique  Effect of irrigants  Effect of sealer  Effect of obturating material  Lesion associated with implant surgery  Lesion associated with third molar removal  Effect of mandibular fracture  Conclusion  References
  • 70.
    Needle breakage  Occuresat the hub  Causes  Intentional bending  Sudden unexpected movement of patient  Forceful contact with bone  Management  Refer to oral surgeon  Locate the fragment  Remove under anesthesia  Prevention  Don’t use short or 30 gauge needle  Do not insert to its hub  Do not bend
  • 71.
    Prolong anesthesia orparesthesia  Persistent anesthesia or altered sensation beyond the expected duration  Causes  Trauma to the nerve  Contamination with alcohol  Insertion of needle into foramen  Hemorrhage around neural sheath  Problems  Self inflicted injury  Hyperesthesia  Management  Resolve within 8weks  Tincture of time
  • 72.
    Facial nerve paralysis Cause  Introduction of LA into the capsule of parotid gland  Over insertion of needle  Problems : unilateral paralysis of face  Management  Contact lenses should be removed  Eye patch applied
  • 73.
    Trismus  It isprolonged tetanic spasm of the jaw muscles by which normal opening of the muscle is restricted  Causes  Trauma to muscles or blood vessel  Contaminated solution  Management  Heat therapy  Analgesics  Muscle relaxants (diazepam)
  • 74.
    Soft tissue injury Seen in younger children, disabled children  Management  Analgesics  Lukewarm saline rinse for swelling  Antibiotics  Lubricants application
  • 75.
    Hematoma  Localized collectionof extravasated blood.  Cause : injection into vessels  Management  Direct pressure application  Don’t apply heat.it worsen the situation.  Cold pack
  • 76.
    Burning on injection  Cause Acidic pH of the solution  Rapid injection  Contamination  Management  Buffering the LA  Slowing the speed Infection  Cause  Contamination of needle before injection  Prevention  Avoid contamination  Management  Antibiotic  analgesic
  • 77.
    Edema  Causes  Traumaduring injection  Infection  Allergy  Hemorrhage  Problem  Airway obstruction  Management  Resolve on its own  If produced by infection antibiotic is given  Histamine blocker
  • 78.
     Lidocaine 4.4mg/kg  With Adrenalin 7mg/kg Drug overdose Cardivascular effect CNS effect 1.8-5 anti dysarythmic action 4.5-7 cns depression 5-10 ecg alteration 7.5-10 tonic clonic >10 cardiac arrest >10generalized cns depression
  • 79.
    Minimal to moderateoverdose levels  Talkativeness, apprehension, excitability  Slurred speech, euphoria, nystagmus, sweating, vomiting  Disorientations, loss of response to painful stimuli  elevated blood pressure, heart rate Moderate to high overdose levels  Tonic clonic seizure followed by CNS depression
  • 80.
    Allergy 1. Early phase:skin reactions  Pruritus, erythema, urticaria, nausea, vomiting  Inflammation of nose & mucous membrane 2. Gastrointestinal & genitourinary disturbances  Abdominal cramp, diarrhea  Fecal & urinary inconsistence 3. CVS symptoms  Pallor, palpitation, tachycardia PRURITUS URTICARIA
  • 81.
  • 82.
    Motor examination ofmandibular nerve  For temporalis muscle – hollowing out of temporal fossa  For masseter – clenching of jaw  Tensor tympani – hyperacusis  Pterygoid – sidewise movement of jaw video
  • 83.
    Referred pain Cancer oftongue Effect on lingual & Auriculotemporal nerve Pain radiate to ear & temporal fossa Rx – sectioning of lingual nerve
  • 84.
    Jaw jerk reflex Both afferent & efferent path supplied by mandibular nerve  Tapping of chin causes contraction of masseter muscle.  Unilateral lesion cause depression of reflex  Bilateral supranuclear lesion causes accentuated response.
  • 85.
    Trigeminal neuralgia  Synonym– TIC DOLOUREUX (Nicholas Andre,1756) ,prosoplegia.  Peripheral disease affecting sensory root.  Sudden attack of severe pain.  Etiology : usually idiopathic, demyelination, petrous ridge compression, intracranial tumor.
  • 86.
    Clinical features  Unilateral,short, stabbing severe pain.  F > M  Right > left  Don’t occur during sleep.  TRIGGER ZONE Central portion of face Nasolabial fold Lip, periorbital area tongue
  • 87.
    Differential diagnosis  Migraine Sinusitis  Dental pain  Trotters syndrome
  • 88.
    Management Medical • carbamazepine • Gabapentin •Baclofen • Sodium valporate Surgical • Glycerol injection • Microvascular decompression • Percutaneous rhizotomy • Gamma knife radiosurgery
  • 90.
    Anatomic variations  Bifidmandibular nerve  Trifid mandibular nerve  Accessory mandibular foramen  Accessory mylohyoid nerve  Retromolar foramen  Contralateral innervation of anterior teeth  Various shape of canal – round, tear drop & dumbbell shape
  • 91.
    Bifid mandibular canal Prevalence= 0.5-0.9% ajith A et al ’05
  • 93.
  • 94.
  • 95.
    Age changes  Degeneration Decrease number of myelinated fiber
  • 96.
  • 97.
  • 99.
    1. Lesion associatedwith anesthetic technique  Due to direct injury with needle- lingual nerve  Due to anesthetic solution- articaine  Anxious patient, unexpected movement
  • 100.
    2.Lesion related toEndodontic procedure A. Position of tooth B. By periapical infection C. By biomechanical preparation D. By irrigating solution E. By root canal sealer F. By gutta percha
  • 101.
    Proximity of rootapex  The proximity of the roots of the 2nd premolars and 1st and 2nd molars  Causes paresthesia  to avoid techniques of hot condensation  Use of MTA sealed apex
  • 102.
    4 possible typesof factors that can cause tissue damage and lead to develop symptoms: 1. Chemical factors because of the neurotoxic effects of sealer or irrigating solutions. 2. Mechanical trauma from over-instrumentation 3. A pressure phenomenon from the presence of core filling material or sealer within the inferior alveolar canal 4. Overheating of tissues because of incorrect warm condensation techniques (Nikolaos et al,2017)
  • 103.
    Effect of Biomechanical Preparation& Obturation  Direct damage during BMP  Reversible and irreversible blockage of nerve conduction or by alteration of the nerve membrane potential  Disruption of apical constriction  Repair by scarring
  • 104.
    Irrigation  Hypochlorite accident When apical foramina has been destroyed  Extreme pressure  Binding of the needle
  • 105.
    Root canal sealer Factorsincrease the risk of sealer extrusion  Over-instrumentation  The complexity of the anatomy of the root canal system,  Excessive amount of sealer,  Excessive compaction force,  Hydrostatic pressure,  The use of lentulo spirals,  Immature canal apices or root tip resorption
  • 106.
     Experimental studieshave shown that sealers which contain both eugenol and paraformaldehyde were the most toxic  could inhibit conduction of the action potential of the nerves  Paraformaldehyde is a potent neurotoxin and may cause chemical destruction of the nerve axon because of its gaseous nature  Brodin et al. reported that Endomethasone can irreversibly inhibit the conduction in the rat phrenic nerve.
  • 107.
    3. Lesion dueto dental implant surgery  Due to inadequate radiological & clinical diagnosis  Recklessness of clinicians  Length of implant
  • 109.
    4. Lesion relatedto third molar removal surgery  Due to inexperienced clinician  Loss of integrity of cortical bone of inferior alveolar canal.  Proximity of the canal with tooth.  When path of lingual nerve is in retromolar pad area
  • 110.
    Preventive method  Coronectomy Wang et al. proposed the use of orthodontic traction  Tolstunov et al. proposed pericoronal osteotomy
  • 111.
  • 112.
  • 113.
  • 114.
    5. Mandibular fractures In a study conducted by Bede et al. found that linear displacement and comminuted fractures caused more nerve lesions  longer period of recovery.  Recovery of nerve function in 91% of cases was obtained
  • 116.
  • 117.
    Treatment of nervelesion  Administration of vitamin B12  Microsurgery
  • 118.
    Conclusion  Mandibular nerveis principal nerve supply of mandible.  As an endodontist we should have thorough knowledge of distribution.  We should be careful while performing any endodontic procedure, be it nerve block, BMP, sealer application or obturation.
  • 119.
    References 1. Gray’s anatomy– 3rd edition 2. Chaurasias human anatomy – 5th edition 3. Handbook of local anesthesia – Malamed 1st edition 4. Manual of local anesthesia in dentistry – AP Chitre 5. Atlas of human anatomy – Netter 6. Journal of endodontics 7. Pubmed 8. www.google.co.in

Editor's Notes

  • #9 Mn has large sensory and small motor root.
  • #13 Intracranial course and Extra-cranial course. SEE THE VIDEO
  • #14 Mandibular teeth & gingiva. Skin of temporal region, auricle. Lower lip, lower part of face. Muscles of mastication. Anterior 1/3 of tongue.
  • #15 Supplies dura of middle cranial fossa.
  • #16 Gives motor root to otic ganglion that does not relay & supplies tensor vali palatine & tensor tympani
  • #17 Superficial head & deep head. Fibers runs downward & backwards.
  • #18 Fibers runs backwards & laterally for insertion
  • #22 Also supply TMJ
  • #23 Superficial & deep head from deep surface Superficial fiber runs downward n bkward at 45 Deep fibr run vertically
  • #28 Lower part – by great auricular & auricular branch of vagus nerve. Also supplies secretomotor to parotid & TMJ
  • #30 Fibers of chorda tympani which is secretomotor to submandibular & sublingual gland & gustatory to ant 2/3rd of the tongue are distributed through lingual nerve.
  • #33 Accompanied by the inf alveolar artery. Mylohyoid nerve pierces sphenomandibular ligament with mylohyoid artery , runs along the mylohyoid groove. Supplies to ant belly of digastric.
  • #35 Situation- jus below foramen ovale. Medial to mandibular nerve, lateral to tensor vali palatine. Surrounds nerve to lateral pterygoid.
  • #42 Area of injection landmark procedure
  • #48 Place figure at mucobuccal fold at first molar area. Run anteriorly till concavity or irregularity felt.
  • #49 Given by George albert Edwards gow gets from australia
  • #51 Keep pt mouth open for 1-2 mins Failure happens due to closure of mouth.
  • #54 Given by joseph akinosi. In 1960 similar method ws given by Vazirani. So the name. In 1992 wolf gave modification. Needle is bended 45 degree
  • #62 Described as Peridental injection in 1912-1923. Regained popularity in 1980 coz of manufacturer Greatest benefit- provide pulpal & soft tissue anesthesia in localized area. Malamed reported a clinical trial- shows 74% pt preffered pdl inj. Coz lack of lingual & labial soft tissue anesthesia.
  • #64 Specialized technique uses STA (single tooth anesthesia ) device C-CLAD computer controlled LA delivery
  • #66 injection in the first stage 3–6 mm distance, second stage 12 mm distance, and in the third stage 24 mm distance of needle insertion
  • #80 Nystagmas- disorder of ocular motor instability resulting in spontenious involuntary ossilation of eye
  • #81 Anphylactic or hypersensitivity rxn Cytotoxic rxn Immune complex mediated Cell mediated PREVENTION- ASK HISTORY BEFORE. USE H1 BLOCKER. GA OR ESTER LA
  • #91 Ueda et al. [12] classified IAN canal into three groups according to its morphology: round/oval, teardrop, and dumbbell shapes
  • #96 We concluded that Goto's modification of Masson-Goldner's goto stain method is the best staining method at present for the morphometric evaluation of nerve fibers'''')
  • #100 lidocaine was involved in 25%, articaine in 33% and prilocaine in 34% of cases with paresthesiae. However, the study of Hillerup et al. [8] concludes that articaine provokes a higher Neurotoxicity. Injection of local anesthetic solutions contaminated by alcohol or sterilizing solution may produce irritation resulting in edema and increased pressure, leading to paresthesia. Alcohol, especially, is neurolytic and can produce paresthesia lasting for months to years. Another factor to consider is trauma to the nerve sheath by the needle. In these cases, the patient reports the sensation of an electric shock. Hemorrhage into or around the neural sheath may increase pressure on the nerve and lead to paresthesia.22
  • #102 The proximity of the roots of the 2nd premolars and 1st and 2nd molars, should remind us of the possibility of nerve damage as a result of a little careful manipulation of endodontic filling materials. If there is a very close relationship, we should question the need to avoid techniques of hot condensation, which are potentially more extrusive and require greater control, as well as to assess the proper caliber of the apex. In these cases, the MTA sealed apex can avoid uncomfortable complications [15]. .Paresthesia resulting from periapical pathosis or various stages of root canal treatment is of great importance in the field of endodontics.
  • #104 Grossman found that repair of mechanical damage to the IAN by scarring can cause immediate but temporary paresthesia. Furthermore, excessive preparation of the root canal often results in disruption of the apical constriction,25 which in turn, is responsible for extrusion of irrigants, medicaments and obturation materials (gutta-percha and sealer) into the periapical region and subsequent chemical and mechanical nerve injury.
  • #105 NaOCl beyond the apical foramen may occur in teeth with wide apical foramina or when the apical constriction has been destroyed during root canal preparation or by resorption. In addition, extreme pressure during irrigation or binding of the irrigation needle tip in the root canal leaving no room for the irrigant to leave the root canal coronally may result in large volumes of the irrigant contacting apical tissues. If this occurs, the excellent tissue-dissolving leads to tissue necrosis.
  • #106 Commonly happens for premolar n molar Many authors believe that the extruded root canal filling material does not remain in one specific area of the antrum and acts as a foreign body. The ciliated mucosal cells tend to move it towards the natural orifice, which may then become occluded13. Stasis of secretion leads to an anaerobic condition which favors the growth of Aspergillus spores. In most cases, Aspergillus infection is caused by root canal filling materials which contain zinc oxide-eugenol (ZOE) and paraformaldehyde that are accidentally introduced into the sinus. The results are reactions of inflammation and the blocking of ciliary movement.
  • #107 contain both eugenol and paraformaldehyde, such as Endomethasone and N2 The pain can be spontaneous, intermittent, or permanent. Eating, speaking, cold, or heat may trigger its onset. The patient may also complain of a burning sensation, a feeling of ‘pins and needles’, or pressure on the teeth18. Pain can be accompanied by local inflammatory signs with the tooth painful on percussion, painful upon palpation of the buccal alveolar process or a combination of signs of mechanical trauma and inferior dental nerve inflammation with pain or numbness of the lower lip.
  • #108 in cases of severe mandibular atrophy, the use of short implants constitute a valid alternative
  • #112 Long et al. [23] carried out a systematic review of this alternative technique. They concluded that coronectomy allows, in a high percentage, the migration of the remaining roots away from the path of the nerve,.
  • #113 Wang et al. [29] and Bonetti et al. [30] propose the use of orthodontic traction for a period of 3 to 10 weeks, placing microimplants or orthodontic brackets in antagonistic maxillary molars for third molars disimpaction. Once the third molar roots are away from the canal, then they extract them, thus preventing the nerve injury [29,30.
  • #114 Tolstunov et al. proposed an alternative to coronectomy, called pericoronal ostectomy that achieves satisfactory results with only temporary neurodeficiency. This technique is performed by means of an osteotomy at the level of the clinical crown; then, we wait for a third molar eruption