This presentation gives a pictorial overview and is self explanatory .Can be used to have through understanding about the pathway of trigeminal nerve.

1. TRIGEMINAL NERVE

2. Nervous system is the most complex system
in the body, it is responsible for
• Behavior
• Thought
• Action
• Emotion reflects its activity

3. Classification of Nerve System
1. Anatomical
• Central nervous system
• Peripheral nervous system
2. Functional
• Afferent
• Efferent
• Somatic
• Autonomous

4. CELLULAR ORGANIZATION OF N.S
Nervous system consists of two principal
categories of cells.
• Nerve cells or neurons
• Supporting cells or neuroglia

5. CRANIAL NERVES
• There are 12 pairs of cranial nerves, out of
these 2 pairs arise from forebrain and 10
pairs from brain stem.
• All the 12 pairs of cranial nerves are
attached on the ventral aspect of brain
except the 4th pair which is attached on
dorsal aspect.

6. Morphological classification
Those supplying muscles derived from cranial myotomes (Motor)
• Oculomotor
• Trochlear
• Abducent
• Hypoglossal
• Accessory
Muscles derived from brachial arches (Mixed)
• Trigeminal
• Glassopharyngeal
• Vagus
• Facial
Those associated with special sense organs (Sensory)
• Olfactory
• Optic
• Vestibulocochleor

8. • The fifth vertebrate peripheral nerve that
emerges from within the skull.
• It is sensory from the head, but motor to the
jaw muscles.
• The largest cranial nerve.
• It was described by Fallopius and again by
Meckel in 1748.
• The term trigeminal was given by Winslow
on account of its three divisions.

9. • The part of parasympathetic craniosacral
outflow
• It is mixed nerve ( sensory and motor )
• Contains 1,70,000 sensory fibres
7,700 motor fibres
• The 3 divisions have approx
Ophthalmic 26,000
Maxillary 50,000
Mandibular 78,000

10. EMBROYOLOGY

13. NUCLEI

15. There are four trigeminal nuclei: one motor and three sensory
The motor nucleus of CNV is in the superior part of the
pons, deep to the floor of the 4th ventricle.
The mesencephalic nucleus of CNV is lateral to the cerebral
aqueduct.
 The principal sensory nucleus is in the dorsolateral area of
the pontine tegmentum at the level of entry of the sensory
fibres.
The spinal nucleus of CNV is in the inferior part of the pons
and throughout the medulla

16. SENSORY NUCLEI
• The sensory function of the trigeminal nerve is to provide the
tactile, proprioceptive, and nociceptive afference of the face
and mouth.
Mesencephalic nucleus
First order sensory nucleus
Cell body of pseudounipolar neurons exception to a general rule that
first order neuron of CN lie outside CNS.
Relay proprioception from muscle of mastication, EOM, facial muscles.
Forms monosynaptic reflex arc .
Situated in midbrain just lat to aqueduct.

17. Principal sensory nucleus-
lies in pons lat to motor nucleus
relays discriminitive touch
Spinal nucleus-
extends from caudal end of principal sen. Nuc.
In pons to 2nd or 3rd spinal seg where its conti with
sub.Gelatinosa.
Divided in :
PARSR ROSTRALIS
PARS INTERPOLARIS
PARS CAUDALIS

19. MOTOR NUCLEUS
• The motor function activates the muscles of the mastication, the
tensor tympani, tensor veli palatini, mylohyoid, and anterior
belly of the digastric.
• Innervates muscles of mastication
tensor tympani and tensor palatini
• Derived from first branchial arch.
• Located in pons med. To princi sen. Nuc.

20. FUNCTIONAL COMPONENTS
SENSORY ROOT
GENERAL SOMATIC AFFERENTS
FACE, SCALP, TEETH, GINGIVA, ORAL MUCOSA, NASAL CAVITIES, PNS
,CONJUNCTIVA AND CORNEA.
Pain,temp,light touch, pressure proprioception
trigeminal gang. Bypasses trigem gang.
sensory root.
descending fibres ascending fibres

21. descending fibres ascending fibres
Spinal nuc. Principal sen nuc. Mesencephalic
trigeminothalamic tract
Thalamus
post central gyrus cerebral cortex

22. MOTOR NUCLEUS
MOTOR ROOT
MANDIBULAR NERVE
muscles of mastication tensor tympani
massetor tensor palatini
lat med pterygoids
temporalis

23. SEMILUNAR OR GASSERIAN
GANGLION
• Cresentric in shape with convexity anterolat.
• Contains cell bodies of pseudounipolar
neurons.
• LOCATION: lies in a bony fossa at apex of the
petrous temporal bone on floor of middle
cranial fossa , just lat to post. Part of lat wall of
the cavernous sinus.

25. • COVERINGS: covered by dural pouch =
MECKLES CAVE OR CAVUM TRIGEMINALE.
Roof- 2 layers of dura
floor- 1 dural and 1endosteal dural layer.
cave lined by pia and arachnoid thus the
ganglion is bathed in CSF.
• ARTERIAL SUPPLY: ganglionic branches of ICA,
middle meningeal artery and accessory
meningeal artery.

29. OPTHALMIC NERVE

32. SO
STN SON
LPS
SR
LG
MR
LR
LN
FN
NCN
TN

34. PEN AEN
ITN
MR
LCN
SCN
LG
LN
LR
CG
AN
INT DIV ON
NCN
Sup Div of ON

38. MAXILLARY NERVE

50. MANDIBULAR NERVE

64. Applied Anatomy

65. TRIGEMINAL NEURALGIA
DEFINITION:
It is defined as sudden
usually unilateral,
severe,
brief,
stabbing,
lancinating,
recurring pain in the distribution of one or more
branches of the Vth cranial nerve.

66. HISTORICAL REVIEW OF TRIGEMINAL
NEURALGIA:
JOHN LOCKE in 1677 gave the first full description with its
treatment.
NICHOLAS ANDRE in 1756 coined the term ‘Tic Doloureux’.
JOHN FOTHERGILL in 1773 published detailed description of
trigeminal neuralgia.

67. TIC DOULOUREUX:
Tic douloureux painful jerking
It is a truly agonizing condition, in which the patient may clunch
the hand over the face & experience severe, lancinating pain
associated with spasmodic contractions of the facial muscles during
attacks
– a feature that led to use of this term

68. AETIOLOGY:
Usually idiopathic
Demylination of the nerve
Multiple sclerosis
Petrous ridge compression
Post – traumatic neuralgia
Intracranial tumours
Intracranial vascular abnormalities
Viral etiology

69. PATHOGENESIS:

70. GENERAL CHARACTERISTICS:
Incidence: 8 : 1,00,000
Age: 5th – 6th decade of life
Sex: Female > male ; 1.6 > 1.0
Affliction for side: Right > left
Division of trigeminal nerve
involvement:
V3 > V2 > V1

71. CLINICAL CHARACTERISTICS:
Manifests as a sudden, unilateral, intermittent paroxysmal,
sharp, shooting, lancinating, shock like pain, elicited by
slight touching superficial ‘trigger points’ which radiates
from that point, across the distribution of one or more
branches of the trigeminal nerve.
Pain is usually confined to one part of one division of
trigeminal nerve.
Pain rarely crosses the midline.
Attacks do not occur during sleep.

72. Pain is of short duration, but may recur with variable frequency.
In extreme cases, the patient will have a motionless face – the
‘frozen or mask like face’.
Common trigger zones include:
Cutaneous Intraoral
Corner of the lips Teeth
Cheek Gingivae
Ala of the nose Tongue
Lateral brow

73. DIAGNOSIS:
From well taken history
CT – scan
MRI
Diagnostic nerve block

74. TREATMENT MODALITIES:
MEDICAL SURGICAL

75. MEDICAL MANAGEMENT:
CARBAMAZEPINE:
Trade name: Tegretol
Carbitrol
PHENYTOIN:
Trade name: Dilantin
GABAPENTIN:
Trade name: Neurontin
BACLOFEN:
Trade name: Lioresal
TRICYCLINE ANTIDEPRESSANTS

76. SURGICAL MANAGEMENT:
PERIPHERAL INJECTION:
It has been known that injection of destructive substance into
peripheral branches of the trigeminal nerve, produces anaesthesia
in the trigger zones or in areas of distribution of spontaneous pain.
(A) LONG ACTING ANAESTHETIC AGENTS:
Without adrenaline such as bupivacaine with or without
corticosteroids may be injected at the most proximal
possible nerve site.

77. (B) ALCOHOL INJECTION:
0.5 – 2 ml of 95 % absolute alcohol can be used to block the
peripheral branches of the trigeminal nerve.
Aim is to destroy the nerve fibres.
It produces total numbness in the region of distribution of
the nerve that was anaesthetized.
Complication:
Necrosis of the adjacent tissue
Fibrosis
Alcohol induced neuritis

78. PERIPHERAL NEURECTOMY (NERVE AVULSION):
CRYOTHERAPHY:

79. GASSERIAN GANGLION PROCEDURES:
PERCUTANEOUS RHIZOTOMY:

81. OPEN PROCEDURES ( INTRACRANIAL PROCEDURES):
(A) Microvascular decompression of the trigeminal nerve
sensory root:
(B) Trigeminal root section:

82. Trigeminal neuropathy
Sensory loss of face or weakness of the jaw muscles
Causes- SLE,
sjogren syndrome
herpes zoster
leprosy
meningioma
schwanomma

83. Wallenberg Syndrome (Lateral Medullary
Syndrome)
• In the medulla, the ascending spinothalamic tract (which
carries pain/temperature information from the opposite side of
the body) is adjacent to the descending spinal tract of the
fifth nerve (which carries pain/temperature information from
the same side of the face).
• A stroke that cuts off the blood supply to this area (e.g., a clot
in the posterior inferior cerebellar artery) destroys both tracts
simultaneously.
• The result is loss of pain/temperature sensation (but not
touch/position sensation) in a unique “checkerboard” pattern
(ipsilateral face, contralateral body) that is entirely
diagnostic.

84. Herpes zoster ophthalmicus
• Recurrent neurocutaneous inf. In opth. Div. of trigeminal
dermatome, most freq. affecting nasociliary branch
• HHV3 / vericella zoster
• Gasserian ganglion
ophthalmic nerve
Supraorbital N. Infraorbital N.
Supratrochlear N.
Infratrochlear N.
Nasal N.

85. • Pain precedes skin lesion
• C/P is hemifacial unioccular
• Cutaneous lesions evolve over few days
Cutaneous lesion
MP rash
Vesicle
Pustules
Crust
Permanent scar

86. Neurotrophic keratitis
• Occurs dt partial or complete corneal anaesthesia dt loss of
sensory innervation by the trigeminal N.
• There is impaired response to corneal microtrauma as a result of
impaired regeneration and healing of corneal epi.
• Causes: infections viz HSV, VZV, leprosy
traumatic V N injury
ablation of gasserian ganglion
chemical burns
topical anaesthatic abuse, betablockrs,NSAIDS
refractive Sx
contact lens wear
systemic: DM,MS, stroke, brainstem
haemorrhage, aneurysm
congenital

87. Cavernous sinus syndrome
• Multiple cranial neuropathies
Exophthalmos, ocular motor defects
Horner’s syndrome
• Sensory loss in V1 and / or V2.
• Pupils may be spared or involved.
• Causes: bacterial thrombophlebitis
actinomycosis
rhinocerebellar mucormycosis
aspergillosis
tolosa hunt syndrome
neoplasms
vascular lesions

88. Gradenigos syndrome
• Petrous bone osteitis due to otitis media
• Characterized by I/L trigeminal N palsy (Va, Vb)
retro orbital pain
I/L sixth N palsy.

89. Clinical Implication in Periodontics
Posterior Superior • Mandibular anesthesia
Alveolar block
• Trismus
LA • Paresthesia
• Burning sensation
• Position of lingual nerve
Flap Retraction • Mental nerve
Nicking of artery & • Hematoma
vein
• Apical end should be 2mm away from the nerve
Implant • Drilling of implant
• Incision should be 1-2 mm away from palatine
Palatal Flap nerve
• Blade should be kept vertical to palate.

90. REFRENCES
• Human Anatomy ,vol.3 Head , Neck & Brain B.D Churasia
• Cunningham’s Manual of Practical Anatomy vol.3
• Gray’s Anatomy Standring 39th Edition
• Medical Embroyology Langham 8th Edition
• IB Singh Textbook of Anatomy 2nd Edition
• Textbook of oral surgery Neelima Malik
• Textbook of Local anesthesia Monheim
• Local Anesthesia Malamed
• Clinical Periodontology & implant Dentistry Lindhe 4th Edition

91. THANK YOU