Trigeminal Nerve

2. PRESENTATION BY:
Mohamed Abdul Haleem
1st
Year Perio PG
KVG Dental college &
Hospital, Sullia.

3. 1.Introduction.
2.Structure of a nerve.
3.List of cranial nerves and its classification.
4.Embryology of trigeminal nerve.
5.Nuclei of trigeminal nerve.
6.Trigeminal Ganglion.
7.Course of trigeminal nerve.
8.Branches.
9.Ganglia associated with trigeminal nerve.
10.Applied anatomy.
11.Conclusion.
12.Bibliography.

4. The nervous system of man is made up of innumerable
neurons which constitute the nerve fibres
Neuroanatomy

5. Nerve :
A bundle of fibers that uses chemical and electrical
signals to transmit sensory and motor information from one part
of the body to the another.
Neurons :
These are specialized cells that constitute the functional
units of the nervous system and has a special property of being
able to conduct impulses rapidly.

6. Elementary Structure of a Neuron
Neuron consists of a cell body also called as soma or perikaryon.
It gives off a variable number of processes called as neurites.
They are of two types:
-Dendrites
-Axon

7. Elementary Structure of a Neuron
Neurons does not have centromsome ---- Can never be
reproduced ---- As it cannot undergo cell division
Each neuron has only 1 axon
The largest axon is about 1 meter

8. Types of a Neuron Based on number of poles
Unipolar/Pseudo-unipolar –
single pole - Both axon and
dentrite arise from a single pole
Bipolar – 2 poles – 1 for axon
and 1 for dentrite
Multipolar – many poles – 1 for
axon and the rest all for dentrite –
2 types,
Golgi Type NeuronsⅠ
Golgi Type NeuronsⅡ
Anaxonic - axon cannot be
distinguished from dendrites

9. Types of a Neuron Based on its length
Golgi Type Neurons – Long Axons --- as long as Ⅰ 50-70 CM
Golgi Type Neurons – Short Axons --- few Ⅱ microns in length
(Interneurons)

10. AXON has following structures from inside to
outside:
Axon.
Myelin sheath.
Endoneurium- which is the connective
tissue layer. It separates and encircle each
nerve fibre.
Perineurium- it imparts strength to the nerve as well as
resistance to spread of infection.
Epineurium- consists of loose areolar connective tissue. It
Contains lymph vessels and blood vessels.

11. Basic difference between axon and
dendrites
AXON
 Extend for a considerable
distance away from cell body.
 Has a uniform diameter
 Devoid of nissl granules.
 Motor fibers have longer
axons
 Fundamental functional
difference is that the impulse
travels away from the cell
body.
DENDRITES
 They terminate near
the cell body.
 Irregular in thickness
 Nissl granules extend
into them.
 Sensory fibres have
longer dentrites
 Nerve impulse travel
towards the cell body.

12. 12 Cranial Nerves

13. Classification of cranial nerves
SENSORY CRANIAL NERVES: Afferent fibers
ⅠOlfactory nerve
ⅡOptic nerve
Ⅷ Vestibulocochlear nerve
MOTOR CRANIAL NERVES: Efferent fibers
Ⅲ Oculomotor nerve
Ⅳ Trochlear nerve
ⅥAbducent nerve
Ⅺ Accessory nerv
Ⅻ Hypoglossal nerve
MIXED NERVES: Both fibers
ⅤTrigeminal nerve,
Ⅶ Facial nerve,
ⅨGlossopharyngeal nerve
ⅩVagus nerve

14. Attachment to Brain
Cranial Nerve Its Attachment
Ⅰand Ⅱ Fore brain
Ⅲand Ⅳ Mid brain
Ⅴ, , andⅥ Ⅶ Ⅷ Pons
Ⅸ, , andⅩ Ⅺ Ⅻ Medulla

15. Embryology of The Nerve
During the development of embryo, the pharyngeal
arches appear in the fourth and fifth week.
It give rise to six pharyngeal arches, of which the 5th
arch dissapears.

16. Each arch is characterized by its own:
Muscular component
 Nerve component
 Arterial component
 Skeletal component
Trigeminal nerve is derived from 1st
pharyngeal arch

17. Musculature of the first pharyngeal arch includes:
1. Muscles of mastication :
• Temporalis
• Masseter
• Pterygoids
2. Anterior belly of diagtric
3. Mylohyoid
4. Tensor tympani
5. Tensor palatini
The nerve supply to these muscles is provided by mandibular
division of trigeminal nerve.

18. Mesenchyme from the 1st
arch also contributes to the dermis of
the face,hence sensory supply to the skin of the face is provided
by ophthalmic, maxillary and mandibular branches of the
trigeminal nerve.

19. Nuclei of trigeminal nerve

20. It has got 4 nuclei :
1) Main sensory nuclei
2) Spinal nuclei
3) Mesencephalic nuclei
4) Motor nuclei -
Nuclei of trigeminal nerve
Purely Sensory
Motor

21. 1.Mesencephalic nuclues in midbrain.
2.Main sensory nucleus situated in upper pons.
3.Spinal nuclues in upper pons to C2 segment of spinal cord.
4.Motor nucleus situated in upper pons.

22. Sensory Nuclei
1.Mesencephalic nucleus.
Situated in midbrain.
First order sensory nucleus.
Cell body are of pseudounipolar
neurons.
Recieves general somatic afferent
fibres.
Relay proprioception sensory supply to :
-Muscles of Mastication
-Facial Muscles
-Eye

23. 2. PRIMARY/SUPERIOR SENSORY NUCLEUS
Situated in upper part of pons lateral to motor nucleus.
Recieves general somatic afferent fibres.
Relays impulses of touch and pressure from skin and
mucous membrane of facial region.

24. It extends from caudal end of principal sensory nucleus in
pons to 2nd
or 3rd
spinal segment where it continues with sub.
Gelatinosa
3.The spinal nucleus
Divided into three parts :-
1. Subnucleus oralis
2. Subnucleus interpolaris
3. Subnucleus caudalis
It receives general somatic afferent fibres i.e relays the
impulses of pain and temperature of face

25. 4.THE MOTOR NUCLUES
It is situated in upper pons medial to principal sensory
nucleus.
It Contains efferent fibres.
.
Innervates muscles of mastication and tensor tympani
and tensor palatini --- Responsible for movement of the
mandible.

26. THE TRIGEMINAL GANGLION
Also known as Gasserian ganglion or semilunar ganglion.
Occupies a cavity (
Meckel's cave) in the
dura mater that contains
the trigeminal impression
near the apex of the
petrous part of the
temporal bone.

27. It is somewhat crescentic or semilunarin shape, with its
convexity directed anteriomedialy.
The three divisions of the trigeminal nerve emerges from
this convexity.
Neurons are of pseudounipolar type.

28. ASSOCIATED ROOTS AND BRANCHES
The central processes of the ganglion cells forms the large
sensory root of the trigeminal nerve ,which is attached to pons at
its junction with the middle cerebellar peduncle.
The peripheral processes form the three divisions of the
trigeminal nerve.
Sensory
Root
Motor
Root

29. The small motor root of the trigeminal nerve is attached to the
pons superomedialy to the sensory root.
It passes under the ganglion from its medial to the lateral side
and joins the mandibular nerve at the foramen ovale.

30. RELATIONS
MEDIALY - Internal carotid artery and the posterior part of
cavernous sinus
LATERALY - Middle meningeal artery
SUPERIORLY - Parahippocampal Gyrus
INFERIORLY -Motor
root of trigeminal
nerve, greater petrosal
nerve, apex of the
petrous temporal bone
and foramen lacerum

31. ARTERIAL SUPPLY - Ganglionic branches of ICA, middle
meningeal artery and accessory meningeal artery.

32. The sensory fibres during
its course relay on “4”
parasympathetic
ganglions, they are :
1. Ciliary
2. Pterygopalatine
3. Otic
4. Submandibular
These are secretomotor
in nature

33. THE TRIGEMINAL NERVE

34. The Trigeminal Nerve
 5th
Cranial Nerve
 Largest Cranial Nerve, Longest
being vagus nerve
 Also know as Nerves
Trigeminus or Trifacial Nerve
 First described by Gabriele
Fallopius and then later by
Johann Friedrich Meckel in
1748
 Term Trigeminal Nerve was
proposed by Jacob
Benignus Winslow
Gabriele
Fallopius
Johann
Friedrich
Meckel
Jacob
Benignus
Winslow

35. It is a mixed nerve.
Composed of a small motor root and a considerably larger
sensory root.
The sensory root contains 1,70,000 fibres and the motor root
contains 7,700 fibres.

36. Trigeminal nerve
Ophthalmic
(Sensory)
Maxillary
(Sensory)
Mandibular
(Mixed)

37. The Ophthalmic division
Superior and smallest
division.
Wholly sensory.
Arises from the
anteriomedial end of
trigeminal ganglion as a
flat band, 2.5cm long.
Passes forward in the
lateral wall of the
cavernous sinus, below the
oculomotor and trochlear
nerves.

38. Nerve is joined by the filaments from the internal carotid
sympathetic plexus.
It communicates with the oculomotor, trochlear and abducent
nerve.
The abducent communication may be the route by which
proprioceptive fibres from extraocular muscles enter the
trigeminal nuclear complex.

39. Before or just after entering the orbit through the
superior orbital fissure it divides into
Lacrimal
(Smallest)
Frontal
(Largest)
Internal
Nasal
Nasociliary
(Intermediate)
External
Nasal
Supra
Troclear
Supra
Orbital
Posterior
Ethmoidal
Infra
Trochlear
Long
Ciliary

40. Smallest of main ophthalmic branches
Enters the orbit through the lateral part of the superior orbital
fissure
Runs along the upper border of the rectus lateralis with the
lacrimal artery
Lacrimal Nerve
Receives a twing from the
zygomaticotemporal branch
of maxillary nerve.which
contains lacrimal
secretomotor fibres

41. Supplies the lacrimal gland and the adjoining conjunctiva.
Pierces the orbital septum.
Ends in the upper eyelid, where it joins filaments of the
facial nerve.

42. FRONTAL NERVE
Largest branch of the ophthalmic division.
Enters the orbit through the lateral part of the superior
orbital fissure.
Supra
Troclear
(Smaller)
Supra
Orbital
(Larger)
Runs above the
levator palpebrae
superioris
Divides into:

43. SUPRATROCHLEAR BRANCH
It supplies:
Conjunctiva
skin of the upper eyelid
skin of the lower forehead
near the midline

44. Transverses the supraorbital foramen
THE SUPRAORBITAL BRANCH
It supplies:
Frontal air sinus
Upper eyelid
Forehead
Scalp till vertex

45. Intermediate in size between frontal and lacrimaL
Deeply placed in the orbit
Enters the orbit through the lateral part of the superior orbital
fissure and lie between the two rami of the oculomotor nerve
Runs on the medial wall of the orbit between superior oblique
and medial rectus muscle
NASOCILIARY BRANCH

46. BRANCHES:
1. Anterior Ethmoidal –
a. Middle and anterior ethmoidal sinus
b. Medial internal nasal
c. Lateral internal nasal
2. Posterior Ethmoidal –
a. Posterior ethmoidal air sinus
b. Sphenoidal air sinus
3. Long cilliary ganglionic branches –
a. Iris of cornea (Sensory) --- sympathetic --- dilatation ---
mydriasis
4. External nasal –
a. Skin of the ala
b. Tip of the nose
5. Infra trochlear –
a. Both eyelids
b. Side of the nose
c. Lacrimal sac

47. It leaves the trigeminal ganglion
between the ophthalmic and
mandibular divisions as a flat
plexiform band
Passes slightly medial to lateral wall of
cavernous sinus
Gives a sensory branch to the dura
matter within the cranium
It is intermediate division of trigeminal nerve.
Wholly sensory.
The Maxillary Nerve:
ORIGIN:

48. Then leaves the cranium through foraman rotandum,
which is located in the greater wing of sphenoid bone.
Once outside the cranium, it crosses the uppermost part
of the pterygopalatine fossa
As it crosses the pterygopalatine fossa it gives of
branches
Sphenopalatine
Ganglionic
Branches
posterior
superior
alveolar
nerve
Zygomatic
Branches
Infraorbital
nerve

49. On the posterior surface of the
maxilla,entering the orbit through
the inferior orbital fissure
Within the orbit it occupies the
infraorbital groove and becomes
the infraorbital nerve,which
courses anteriorly into the
infraorbital canal
The maxillary division emerges on
the anterior surface of face through
the infraorbital foramen, where it
divides into its terminal branches,
supplying the skin of the face, nose,
lower eyelid and upper lip

50. Maxillary Nerve
1. Within Cranial Cavity
a. Meningeal nerve (Dura matter)
2. Ganglionic branches
a. Orbital
b. Palatine
c. Nasal
d. Pharyngeal
e. Lacrimal
3. Zygomatic
a. Zygomatico Temporal
b. Zygomatico Facial
4. Infraorbital
a. Middle Superior Alveolar
b. Anterior Superior Alveolar
c. Face
i. Palpebral
ii. Nasal
iii. Superior Labial
5. Posterior Superior Alveolar

51. Meningeal nerve:
Also known as nervus meningeus
medius.
It lies within the cranium.
It receives a ramus from the
internal carotid sympathetic
plexus and accompanies the
middle meningeal artery to
supply the duramater.

52. ZYGOMATIC NERVE:-
1. Zygomaticcotemporal: a
communicating secretomotor fibers
given to the lacrimal gland through
lacrimal nerve.
2. Zygomaticofacial: sensory supply to
the skin over zygomatic prominence
and to the anterior part of the temple.
Starts in the pterygopalatine fossa.
Enters the orbit through the inferior orbital fissure.
Runs along the lateral wall to reach zygomatic bone
Just before/after enetering zygomatic bone, it gives of two terminal
branches.

54. It descends from the main
trunk of the maxillary division
in the ptergopalatine fossa.
Through the pterygopalatine
fossa,it reaches posterior
surface of the body of maxilla.
From here it enters maxilla
through the PSA canal
POSTERIOR SUPERIOR ALVEOLAR NERVE

55. Travel down the
posteriolateral wall of the
maxillary sinus.
Provides sensory innervation
to the mucous membrane of
the sinus.
Continuing downward it
provides sensory innervation
to the alveoli,periodontal
ligaments,and pulpal tissues
of the maxillary 3rd
,2nd
and 1st
molar.
Applied anatomy:- During a
nerve block there is great risk
of hematoma formation.

56. The Pterygopalatine Ganglionic Branches:
This ganglion is also known as sphenopalaltine gamglion or
ganglion of Hay Fever
The ganglionic branches of maxillary nerve suspend the
ganglion in the pterygopalatine fossa
It is the largest peripheral parasympathetic gnglion
Serves as relay station for secretomotor fibres to the lacrimal
gland
Topographically related to
maxillary nerve, but functionally it
is related to facial nerve (through
greater petrosal branch)

57. Branches of pterygopalatine nerve includes those that
supply five areas:-
1. Orbit
2. Nasal
a) Superior Posterior Nasal
i. Medial
ii. Lateral
b) Nasopalatine
3. Palate
a) Greater (Anterior)
b) Lesser (Middle &
Posterior)
3. Pharynx
4. Lacrimal

58. The orbital branches supply the periosteum of
the orbit.

59. NASOPALATINE NERVE

60. GREATER PALATINE NERVE:
Emerges on the hard palate through the greater palatine
foramen (usually located about 1cm towards the palatal
midline, just distal to the second molar)
The nerve courses anteriorly supplying sensory innervation to
the palatal soft tissues and bone as far as the first premolar,
where it communicates with the terminal fibres of the
nasopalatine nerve.
It provides sensory
innervation to some parts
of soft palate

61. The Lesser Palatine Nerve:
Emerges from the lesser palatine foramen along with the
posterior palatine nerve.
Provides sensory innervation to the mucous membrane of
soft palate
The posterior palatine nerve:
Innervates the tonsillar
region.

62. THE PHARYNGEAL BRANCH:
It is a small nerve
Passes through the pharyngeal canal and is distributed to the
mucous membrane of the nasal part of the pharynx posterior to
the auditory tube.

63. INFRAORBITAL NERVE
Enters the orbit through the IOF
Runs forward on the floor of the orbit
First in the infraorbital groove, then in the canal
Here it gives two branches
•ASA
•MSA
The nerve terminates by emerging on the face through
infraorbital foramen giving out its terminal branches
•Lower Palpebral
•Lateral Nasal
•Superior Labial

64. THE MIDDLE SUPERIOR ALVEOLAR NERVE (MSA):
Arises from the infra orbital nerve.
Provides sensory innervation to two maxillary premolars and
perhaps to the mesiobuccal root of the first molar and the
periodontal tissues, buccal soft tissues and bone in the premolar
region.
Traditionally it has being stated that the MSA nerve is absent in
30% to 54% of individuals.
In its absence the usual innervations are provided by either the
PSA or the ASA nerve, most frequently the latter.

65. The Middle Superior and Anterior Superior Alveolar
nerve:

66. ANTERIOR SUPERIOR ALVEOLAR NERVE (ASA):
It is a relatively larger branch
Given off from the infraorbital nerve at approximately 6 to 10mm
before the latter exit from the infraorbital foramen
Central and Lateral
Incisors
Canine
Periodontal Tissues
Buccal Bone
Mucous Membrane Of
These Teeth.
It provides pulpal innervation to the:

67. BRANCHES ON THE FACE:
1) The Inferior Palpebral:-
supplying the skin of the lower
eyelid
2) The External Nasal Branch:-
providing sensory innervation to
skin of lateral part of the nose
3) The Superior Labial Branch:-
supplying the skin and mucous
membrane of the upper lip.
The infraorbital emerges through the infraorbital foramen onto
the face to divide into its terminal branches:

68. THE MANDIBULAR DIVISION:
Largest division of trigeminal nerve
Mixed in nature
Has a large sensory root and a small motor root
The sensory root originates from trigeminal ganglion whereas
the motor root originates in the pons and medulla ablongata
The two roots emerge from
the cranium separately
through the foramen ovale
The motor root lying medial
to sensory root
They unite just outside the
skull and form the main trunk
of 3rd
division

69. BRANCHES OF THE MANDDIBULAR NERVE
MANDIBULAR NERVE
Posterior
Division
(Large)
Undivided nerve
(Main trunk)
Divided nerve
Anterior
Division
(Small)

70. Undivided Nerve
Nervus Spinosus
Nerve to Medial Pterygoid Muscle
Divided Nerve
Anterior Division-
Nerve To Lateral Pterygoid
Nerve To Masseter Muscle
Nerve To Temporal Muscle
Buccal Nerve
Posterior Division-
Auriculotemporal Nerve
Lingual Nerve
Mylohyoid Nerve
Inferior Alveolar Nerve
-Incisive
-Mental

71. BRANCHES OF THE UNDIVIDED NERVE:
Meningeal Branch
Enters the skull through foramen
spinosum (along with the middle
meningeal artery)
Supply the dura matter of the
middle cranial fossa
This nerve is also called NERVUS
SPINOSUS

72. NERVE TO MEDIAL PTERYGOID
It is a motor nerve to medial pterygoid muscle

74. BRANCHES FROM ANTERIOR DIVISION:
Motor Branch - To the muscles of
mastication
Buccal Nerve - Sensory innervation to
the mucous membrane of the cheek and
buccal mucous membrane of the
mandibular molars
The anterior division is smaller than the
posterior division

75. Under the lateral pterygoid nerve,it gives off some branches, i.e.
1. The deep temporal nerve- to the temporal muscle
2. The masseter nerve- providing motor innervation to masseter
muscle
3. Lateral pterygoid nerve- providing motor innervation to the
lateral pterygoid muscle

76. Follows the inferior part of
the temporal muscle
Emerges under the anterior
border of the masseter
muscle
At the level of occlusal plane
of the mandibular 3rd
and 2nd
molar
Also known as long buccal nerve
Usually passes between the two heads of the lateral pterygoid
Reaches the external surface of the muscle
THE BUCCINATOR NERVE

77. Provides sensory innervation to:
Crosses in front of the ramus
Enters the cheek through buccinator muscle
1. Skin over the anterior part of
buccinator
2. Buccal gingiva of mandibular
molars
3. Mucobuccal fold in that region
The bucaal nerve does not
innervate the buccinator
muscle,the facial nerve does.

78. THE POSTERIOR DIVISION
Larger division
Mainly sensory
Auriculotemporal
Nerve
Lingual
Nerve
Inferior
Alveola Nerve
(Only Motor)
Divides into
Mylohyoid Anterior
Digastric

79. Then lateraly behind the the
temporomandibular joint in relation
with the upper part of the parotid
gland
Emerging from behind the joint it
ascends posterior to the superficial
temporal vessels over posterior root
of the zygoma
Divides into superficial temporal
branches.
IT HAS TWO ROOTS:
encircles the middle meningeal artery
Runs back under lateral pterygoid on the surface of tensor veli palatini to pass
between the sphenomandibular ligament and the neck of the mandible
AURICULOTEMPORAL
NERVE

80. BRANCHES OF AURICULOTEMPORAL NERVE
a) Two anterior auricular branch-supply the skin of tragus and
sometimes small part of adjoining helix and the
temporomandibular joint
b) Two branches to external acoustic meatus-supply skin of
meatus and the tympanic membrane
c) Superficial temporal branch- supply skin in the temporal
region and connects with the facial and zygomaticotemporal
nerves

81. COMMUNICATIONS-
It communicates with facial nerve providing sensory fibres to the skin
over the areas of innervation of motor branches of facial nerve
It communicates with the otic ganglion providing sensory,secretory and
vasomotor fibres to parotid gland

82. Second branch of the posterior
division of mandibular nerve
Runs between the tensor veli
palatini and lateral
pterygoid,where it is joined by
chorda tympani branch of facial
nerve from here
It decends to rest between the
ramus and medial pterygoid
muscle in the pterygomandibular
space
THE LINGUAL NERVE

83. It runs anterior and medial to the
inferior alveolar nerve whose path
is parallel to it.
It then continues to reach the side
of the base of the tongue slightly
below and behind the mandibular
3rd
molar.
Here it lies just below the mucous
membrane in the lateral lingual
sulcus.

84. It then proceeds anteriorly across the muscles of the tongue
Looping medial to
submandibular duct
(wharton’s duct) to deep
surface of submandibular
and sublingual gland
where it breaks up into
terminal branches

85. SUPPLY OF LINGUAL NERVE
Supplies the mucosa of the floor of the
mouth
lingual gingivae
Mucosa of anterior two third of the tongue
Also carries postganglionic fibres from
submandibular ganglion to sublingual and
anterior lingual glands
APPLIED ANATOMY
Lingual nerve is at great risk during
surgical removal of impacted third molar
During removal of submandibular salivary
gland, the duct must be dissected from
lingual nerve.

86. Largest branch of the mandibular division
Descends medial to the lateral pterygoid muscle and lateroposterior to
lingual nerve
Passes between the sphenomandibular ligament and the mandibular
ramus to enter the mandibular canal via mandibular foramen
INFERIOR ALVEOLAR NERVE
Through out its
path it is
accompanied by
inferior alveolar
artery and inferior
alveolar vein
Nerve travels
anteriorly in the
canal till it reaches
the mental foramen

87. Inferior Alveolar Nerve
APPLIED ANATOMY:-Lower lip and tongue is also
anaesthetized during I.A.N.B,hence young child or physically
or medically handicaaped patients should be informed
prior to administration to avoid soft tissue injury.
Mental Nerve Incisive
Nerve

88. Exists the canal through the mental foramen between and just
below the apices of the premolar,and divides into three
branches that innervates:
Continues forward in the bony canal giving off branches to:
Premolar
Canine
Incisors
Associated Labial Gingiva
THE INCISIVE
NERVE
THE MENTAL NERVE
Skin of the chin
Skin of the lower lip
Buccal mucous membrane from
second premolar to the midline i.e
central incisor region.

89. THE MYLOHYOID NERVE
Just before entering the mandibular canal, the inferior alveolar
nerve gives off a small mylohyoid branch
It pierces the sphenomandibular ligament and enters a shallow
groove on medial surface of mandible
Follows a course
roughly parallel to
inferior alveolar nerve
passes below the origin
of mylohyoid muscle
lies superficial to the
surface of mylohyoid
muscle

90. It is a mixed nerve
Provides motor innervation to:
1. Mylohyoid and anterior belly of digastric
2. Sensory fibres to inferior and anterior surfaces of mental
protuberance
3. Mandibular incisors (sometimes)

91. GANGLIA ASSO WITH THE TRIGEMINAL NERVE
1.CILLIARY GANGLION
connected with nasocilliary nerve by ganglionic
branches in orbit
sensory for orbit

92. 2.PTERYGOPALATINE GANGLION
connected to maxillary nerve in infratemporal fossa
sensory to orbital septum, orbicularis and nasal cavity,
maxillary sinus , palate , nasopharynx.

93. 3. OTIC GANGLION
 lies between trunk of mandibular nerve and tensor
palatini.
Nerve to med pterygoid passes through but does not
synapse in the ganglion.

94. 4.SUBMANDIBULAR GANGLION
Related to lingual nerve, rest on hypoglossus
Supplies posterior ganglionic Parasympathetic
secretomotor fibres to submandibular and sublingual gland.
( Pre-ganglionic
Parasympathetic )

95. APPLIED ANATOMY
1.Trigeminal neuralgia.
2. Herpes zoster ophthalmicus.
3.Wallenberg Syndrome.

96. Also known as Fothergill’s disease,Tic douloureux (painful
jerking)
It is defined as sudden, usually, unilateral, severe, brief,
stabbing, lancinating, recurring pain in the distribution of
one or more branches of trigeminal nerve.
Trigeminal Neuralgia:-
Mean age: 50 y onwards
Female predominance
(male : female = 1:2 ~2:3)

97. It is usualy idiopathic.
The probable etiologic factors are:-
Intra cranial tumors:-Traumatic
compression of the trigeminal nerve by
neoplastic (cerebellopontine angle
tumor) or vascular anomalies eg
arteriovenous malformations
Infections :- granulomatous and non
granulomatous infections involving 5th
cranial nerve.
Pathogenesis of trigeminal neuralgiaPathogenesis of trigeminal neuralgia

98. Petrous Ridge Compression
Intracranial Vascular Abnormalites
Postherpetic Neuralgia
Demyelinating Conditions
Multiple Sclerosis (MS)

99. Pulsation of vessels upon the trigeminal nerve root do not visibly
damage the nerve. However, irritation from repeated pulsations
may lead to changes of nerve function, and delivery of abnormal
signals to the trigeminal nerve nucleus. Over time, this is thought
to cause hyperactivity of the trigeminal nerve nucleus, resulting in
the generation of TN pain.

100. General Characteristics
Incidence:- seen in about 4 in 100000
persons
Age of occurrence:- 5th
to 6th
decade
Sex predilection:-female
predisposition
Side involved more frequently:-right
side
Division of trigeminal nerve involve;
most commonly
mandibular > maxillary >ophthalmic

102. Clinical characteristics:-
Sudden
Unilateral
Intermittent Paroxysmal
Sharp Shooting
Lancinating shock like pain
elicted by slight touching

103. Superficial trigger points which radiates across the
distribution of one or more branches of the
trigeminal nerve
Pain rarely crosses the midline
Pain is of short duration and last for few seconds to
minutes
In extreme cases patient has a motionless face called
the frozen or mask like face
Presence of intraoral or extraoral trigger points

104. TRIGGER ZONE

105. Provocated by obvious stimuli like
Touching face at particular site
Chewing
Speaking
Brushing
Shaving
Washing the face
The characteristic of the disorder being that the
attacks do not occur during sleep.

107. DIAGNOSIS:-
CLINICAL EXAMINATION with
HISTORY is mandatory
Response to treatment with
tablet of carbamazepine is
univeral
Injections of local anaesthetic agents
into patients trigger zone gives
temporarily relief from pain.

108. TREATMENT
Medical treatment
Surgical treatment:-
1. Peripheral injections
2. Peripheral neurectomy
3. Cryotherapy
4. Peripheral radiofrequency
5. Neurolysis(thermocoagulation)
6. Gasserian ganglion procedures

109. MEDICINAL TREATMENT

110. Carbamazapine and phenytoin are the traditional
anticonvulsants given primarilary.
The dosage of the drug used intially should be kept small
to minimum especialy in elderly patients to avoid
nausea,vomiting and gastric irritation.
Dosage should be taken at night so that adequate serum
concentration is present early morning.
Complete blood count,liver function,platelet count
should be done prior to treatment.

111. Visual blurring
Dizziness
Rashes
Hepatic dysfunction
Leukopenia
Thrombocytopenia

112. Onces the pain remission has being achieved the
drug dose should be kept at maintainence level or
withdrawn and restarted if symptoms reappear
When carbamazepine is contraindicated clonazepam
can be given
Co-administration of phenytion or baclofen is also
advocated.

114. The anaesthetic agent without adrenaline
eg bupivacaine with or without
corticosteroids is injected

115. THE ALCOHOLIC INJECTIONS:-
95% ABSOLUTE alcohol in small quantites 0.5 to 2 ml is
given in peripheral branches of trigeminal nerve.
Side effect:-
Repeated injections may cause
Local tissue toxicity
Inflammation
Fibrosis
Burning alcohol neuritis

116. Peripheral neurectomy (nerve avulsion):-
Oldest and the most effective procedure
Simple
Relatively reliable
Indicated in patients in whom
craniotomy is contraindicated due to
age,debility,limited life expectancy
Acts by interrupting the flow of a
significant number of afferent impulses
to central trigeminal apparatus.
Performed mostly on infraorbital,inferior
alveolar,mental and rarely lingual nerve.

117. CRYOTHERAPY FOR PERIPHERAL NERVE
Direct application of
cryotherapy probe (nitrous
oxide probe)
Temperature colder than -60
degree C,for 2-3 minutes
Reapeated three times
Produces WALLERIAN
degeneration without
destroying the nerve sheath

118. Radiofrequency electrode that has the capacity to destroy
the pain fibres is used in this procedure.
Temperature being 65 to 75 degree C for 1 to 2 minutes.
Shown to induce pain remissions in 20% of cases.
PERIPHERAL RADIOFREQUENCY NEUROLYSIS
THERMOCOAGULATION:-

119. RADIO FREQUENCY THERMOCOAGULATION

120. Microvascular Decompression
This procedure involves relocating
or removing blood vessels that are in
contact with the trigeminal root.
Through a small hole in the skull the
arteries that are in contact with the
trigeminal nerve is moved away
from the nerve, and a pad is placed
between the nerve and the
arteries.
If a vein is compressing the nerve,
then the vien is removed.

121. Microvascular Decompression
A part of the trigeminal nerve may
also be dissected (neurectomy)
during this procedure if arteries
aren't pressing on the nerve.
Microvascular decompression can
successfully eliminate or reduce
pain most of the time, but pain can
recur in some people.
Microvascular decompression has
some risks, including decreased
hearing, facial weakness, facial
numbness, a stroke or other
complications.

122. GASSERIAN GANGLION PROCEDURS:-
Includes various procedures:-
1.Gycerol injection
2.Thermocoagulation
3.Ballon compression

123. GYCEROL INJECTIONS:-
Absolute alcohol or phenol-glycerol mixture can be used as
the neurolytic agents.
Agent is injected into meckel’s cave or in the ganglion.
Causes damage to nerve cells presumably through
dehydration.
It induces pain relief in 80%
of the cases.
Also spares the ophthalmic
division and the motor root.

124. THERMOCOAGULATION:-
A radiofrequency electrode that has the capacity to
destroy pain fibres is used.
Alternating currents of high frequency is passed through
the electrode.
It produces ionization in
the biological tissues leads
to coagulation of tissues.

125. BALLON COMPRESSION:-
A Fogarty catheter 1 to 2cm is advanced within the meckels
cave through foramen ovale.
.
Inflated upto 0.75ml at the ventral aspect of the ganglion root
for 1 minute.
.
It destroyes the root fibres.

126. Transcutaneous electrical nerve stimulation
(TENS)
uses low-voltage electrical current for pain relief.
Its a small battery-powered machine about the size of a
pocket radio.
The electrodes are often
placed on the area of pain
or at a pressure point,
creating a circuit of
electrical impulses that
travels along nerve fibers.

127. Transcutaneous electrical nerve stimulation
(TENS)
Another theory is that the electrical stimulation of the nerves
may help the body to produce natural painkillers called
endorphins, which may block the perception of pain.
We can set the TENS machine for different wavelength
frequencies, such as a steady flow of electrical current or a
burst of electrical current, and for intensity of electrical
current.
The electricity from the
electrodes stimulates the nerves
in an affected area and sends
signals to the brain that block or
"scramble" normal pain signals.

128. HERPES ZOSTER OPHTHALMICUS:-
Caused by Varicella zoster
Predilection for nasociliary branch of ophthalmic division of
the trigeminal nerve
CLINICAL FEATURES:-
Cutaneous lesions:-
Rash
Vesicle
Pustule crust
permanent scar

129. Ocular lesions:-
Eyelid:-
Perorbital pain
Oedema
Hyperasthesia
Conjunctivitis
Scleritis
Corneal scarring
Glaucoma
Diagnostic clue – Unilateral distribution of the lesion

130. TREATMENT
Acyclovir 800mg 5 times /day within 4 days of onset of rash
Analgesics
Antibiotic ointments
Systemic steroids 60mg/day
Corneal grafting

131. Wallenberg Syndrome
A stroke which causes loss of pain/temperature
sensation from one side of the face and the other side of
the body.
ETIOLOGY:-
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)

132. A stroke cuts off the blood supply to this area
Destroys both tracts simultaneously.
Results in loss of pain/temperature sensation
in a unique “checkerboard” pattern (ipsilateral
face, contralateral body)
Characteristic diagnostic feature.

133. Conclusion:-
Trigeminal nerve, its anatomic course and branches are very
important from a dentist point of view as inadvertant
surgical procedure may lead to trigeminal nerve injury.
Disorders of Trigeminal nerve are not rare ,knowing about it
will help in formulating appropriate diagnosis and treatment
thus achieving the best possible recovery of Trigeminal
nerve function.
Nerve blocks given for carrying various dental procedures
involves the various branches of Trigeminal nerve, hence to
avoid any complications ,one needs to have a knowledge
about the course and branches of the nerve .

134. Gray’s Anatomy
Anatomy head and neck - ( B.D Chourasia)
Cranial Nerves – ( Wilson Pauwels )
Anatomy for dental Students - ( A.S. Moni)
Handbook of local anaesthesia by stanley malamed
Textbook of oral and maxillofacial surgery - (Neelima Anil Malik)
Harrisson text of internal medicine