TRIGEMINAL NERVE

1. 1

2. TRIGEMINAL NERVE
DEPARTMENT OF PUBLIC HEALTH DENTISTRY
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GUIDED BY
DR.(PROF) VEERANNA
RAMESH
PRESENTED BY
DR.ANANT KUMAR
PG FIRST YEAR
B.I.D.S.H

3. CONTENTS:-
1) INTRODUCTION
2) ANATOMY OF THE TRIGEMINAL NERVE
- NUCLEI OF TRIGEMINAL NERVE
- FUNCTIONAL COMPONENTS
- COURSE AND DISTRIBUTION
- TRIGEMINAL GANGLION
3) DIVISIONS OF TRIGEMINAL NERVE
4) CLINICAL EXAMINATION
5) APPLIED ANATOMY
6) CONCLUSION
7) REFERENCES
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4. INTRODUCTION
 The trigeminal nerve is the fifth cranial nerve,which is the largest of all the cranial nerves.
 It is a mixed cranial nerve as it contains both sensory and motor fibres.
 It is also known as Trifacial and Trigeminus nerve.
 It is first described by GABRIELE FALLOPIUS and then later by JOHANN FRIEDRICH MECKEL in 1748.
 The term trigeminal nerve was proposed by JACOB BENIGNUS WINSLOW.
 It arises by two roots, a posterior larger(sensor) root and the anterior smaller(motor) root.
 The smaller root consist of three or four bundles, in the larger,bundles are more numerous, varying in
number seventy to a hundred .
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5.  It is attached to the lateral part of the pons by its two roots, sensory and
motor.
 The two roots are seperated from one another by a few of the transverse
fibers of the pons.
 The deep origin of the larger or sensory root may be traced between the
transverse fibers of the pons varolii to the lateral tract of the medulla
oblongata, immediately behind the olivary body.
 The two roots of the nerve passes forwards through an oval opening in
the dura mater, at the apex of the petrous portion of the temporal bone.
 The fibers of the larger root enter a large semilunar
ganglion(GASSERIAN), while the smaller root passes beneath the ganglion
without having any connection with it, and joins outside the cranium with
one of the trunks derived from it.
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6. NUCLEI
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7. TRIGEMINAL NUCLEI
 A cranial nerve nucleus is a collection of neurons (grey matter)
in the brain stem that is associated with one or more cranial
nerve.
 Axons carrying information to and from the cranial nerves
form a synapse first at these nuclei.
 It has four nuclei:-
1.Motor nuclei
2.Main sensory nuclei
3.Mesencephalic nuclei
4.Nuclei of the Spinal tract of trigeminal nerve
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8. 1. Motor nucleus : (Special visceral efferent)
- Situated in the middle of the pons.
- Gives rise to the motor root of trigeminal nerve.
 supplies the muscles of mastication, the tensor tympani and
tensor veli palitini muscles, muscles of the eye and the facial
muscles.
2. Sensory nucleus : (general somatic afferent)
- situated within the pons, lateral to the motor nucleus.
- filers convey both exteroceptive and proprioceptive impulses.
 Exteroceptive impulses of touch, pain, thermal senses are
transmitted from the skin of the face and forehead, mucous
membrane of nasal cavities, oral cavities, nasal sinuses ,floor of
the mouth, the teeth, the anterior 2/3rd of the tongue and
extensive portions of the cranial dura.
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9.  Proprioceptive impulses are conveyed from teeth , periodontium,
hard palate and TMJ receptors.
3. MESENCEPHALIC NUCLEUS :-
 Situated in the mid brain lateral to the cerebral aqueduct.
 Receives proprioceptive fibres from the structures supplied by the
trigeminal nerve.
4. NUCLEUS OF THE SPINAL TRACT OF TRIGEMINAL NERVE :-
 It is the downward continuation of the sensory nucleus of trigeminal
nerve into medulla oblongata and upper three segments of the spinal
cord.
 This nucleus is connected to the facial , glossopharyngeal, vagus and
also to the 2nd and 3rd cranial nerve.
 This nucleus receives sensation like pain and temperature from the
trigeminal area.
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10. Roots of the trigeminal nerve :-
 Afferent fibres constitute from the sensory root and the efferent
fibres from the smaller motor root .
 By its two roots the trigeminal nerve is attached to the lateral
of the pons. The sensory root is lateral and motor root is medial
 The two roots enters the middle cranial fossa , the sensory root
lateral and motor root is medial.
 The sensory root joins the posterior border of the trigeminal
ganglion, the motor root does not join the ganglion but it forms
the root of the mandibular nerve.
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11. FUNCTIONAL COMPONENTS
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12. FUNCTIONAL COMPONENTS
1. SENSORY COMPONENTS :-
 Sensation of pain, temperature, touch and pressure from skin
of face, mucous membrane of nose, most of the tongue,
paranasal air sinuses travel along axons.
 The cell bodies lies in the trigeminal ganglion or semilunar
ganglion or Gasserian ganglion.
 It lies at the apex of petrous temporal bone in adural cave
and the Meckel’s cave.
 The central processes of trigeminal ganglion form sensory
root. some fibres ascend and other descend.
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13.  Ascending fibres end in superior sensory nucleus.
 Descending fibers end in the spinal nucleus of V nerve.
2. MOTOR COMPONENTS :-
 The motor nucleus receives impulses from the right and left
cerebral hemispheres, red nucleus and mesencephalic
nucleus.
 Fibres of motor root supply four muscles of mastication and
four other muscles are tensor veli palatini ,tensor tympani,
mylohyoid and anterior belly of digastric.
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14. COURSE AND DISTRIBUTION
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15. COURSE AND DISTRIBUTION
 The trigeminal nerve originates from three sensory
nuclei (mesencephalic, principal sensory, spinal nuclei of
trigeminal nerve) and one motor nuclei (motor nucleus of the
trigeminal nerve) extending from the midbrain to the medulla.
 At the level of the pons, the sensory nuclei merge to form a
sensory root. The motor nucleus continues to form a motor root.
These roots are analogous to the dorsal and ventral roots of the
spinal cord.
 In the middle cranial fossa, the sensory root expands into the
trigeminal ganglion. A ganglion refers to a collection of the
neuron cell bodies outside the central nervous system.
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16.  The trigeminal ganglion is located lateral to the cavernous
sinus, in a depression of the temporal bone. This depression
is known as the trigeminal cave.
 The peripheral aspect of the trigeminal ganglion gives rise
to 3 divisions: ophthalmic (V1), maxillary (V2)
and mandibular (V3).
 The motor root passes inferiorly to the sensory root, along
the floor of the trigeminal cave. Its fibres are only
distributed to the mandibular division.
 The ophthalmic nerve and maxillary nerve travel lateral to
the cavernous sinus exiting the cranium via the superior
orbital fissure and foramen rotundum respectively. The
mandibular nerve exits via the foramen ovale entering the
infra-temporal fossa.
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17. GANGLION
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18. THE TRIGEMINAL GANGLION
SEMILUNAR OR GASSERIAN GANGLION:-
 It develops from neural crest.
o Shape – Cresentric shaped
o Type - Sensory ganglion
o Situation - Cavum trigeminal of the middle cranial fossa.
o Borders - (Anterior - convex border and posterior -concave
border). The concave border is joined by the sensory root of
trigeminal nerve . The ophthalmic , maxillary and sensory root
of mandibular nerve are formed from the anterior convex
border.
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19. RELATIONS:-
 SUPERIORLY: superior petrosal sinus,
free margin of tentorium cerebelli.
 INFERIORLY: motor root of trigeminal nerve,
greater petrosal nerve,
petrous apex,
foramen lacerum.
 MEDIALLY: posterior part of lateral wall of cavernous sinus,
internal carotid artery with its sympathatic plexus.
 LATERALLY: uncus of the temporal lobe , nervous spinosum,
middle meningeal artery and vein.
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20.  BLOOD SUPPLY :-
The Ganglion is supplied by
(a)Internal carotid artery
(b)Middle meningeal artery
(c)Accessory meningeal arteries.
(d)The meningeal branch of ascending
pharyngeal artery.
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21. DIVISIONS OF TRIGEMINAL NERVE
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22. DIVISIONS OF TRIGEMINAL NERVE
1. OPTHALMIC BRANCH (V1)
2. MAXILLARY BRANCH (V2)
3. MANDIBULAR BRANCH (V3)
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23. OPTHALMIC DIVISION (V1)
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24. OPTHALMIC NERVE
 The ophthalmic nerve or first division of the trigeminal nerve is a sensory nerve. It is the
smallest of the all three divisions.
Course :- it leaves the anterior medial part of the ganglion ,passes forwards through the
lateral wall of the cavernous sinus.
 Its fibres are sensory from:-
- The scalp
- Skin of the forehead
- Lining of the frontal and ethmoidal sinuses
- The conjunctiva and the sclera of the eye ball
- Lacrimal gland
- Skin of the lateral angles of the eye
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25. BRANCHES OF OPTHALMIC NERVE
 In the middle cranial fossa , the nerves tentoria branches
from the ophthalmic division to supply the dura.
 It enters the orbit through the superior orbital fissure. It
terminates by dividing into :
a) LACRIMAL NERVE
b) FRONTAL NERVE
i. Supraorbital nerve
ii. Supratrochlear nerve
c) NASOCILIARY NERVE
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26. A) LACRIMAL NERVE
 It is the smallest of the three branches of the ophthalmic
nerve.
Course :- It passes into the orbit at the lateral angle of the
superior orbital fissure. it runs anterolaterally and supplies. -
The Lacrimal gland
- Skin of the upper eyelid
- Lateral part of the eyebrow region
- Conjunctiva of the lateral part of the upper eyelid.
 Lacrimal nerve communicates with the postganglionic
secretory fibers from the sphenopalatine ganglion.
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27. B) FRONTAL NERVE
 It is the largest of the all three branches of the ophthalmic nerve.
Course :- It enters the orbit by way of the superior orbital fissure,
it passes above the levator palpebrae superioris muscle.
Termination :- at about the middle of the orbit , it divides into two
branches.
a)Supra orbital nerve
b)Supra trochlear nerve
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28. a) Supra orbital nerve:-
 it is the largest branch of the frontal nerve.
 It passes forward and leaves the orbit through the supraorbital foramen to supply the skin of the
eyelid ,the forehead and the anterior scalp region to the vertex of the skull.
b) Supra trochlear nerve:-
 It is the smallest branch of the frontal nerve.
 It passes towards the upper medial angle of the orbit.
 It supply the skin of the upper eyelid and lower medial
portion of the forehead.
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29. C) NASOCILIAY NERVE
 It is the third main branch of the ophthalmic division.
Course :- It enters the orbit through the superior orbital fissure crosses the optic nerve superiorly from
the lateral to medial side.
 Branches in the orbit, nasal cavity and face.
A. BRANCHES in the orbit:-
1.Long root of the ciliary ganglion
2.Long ciliary nerve
3.Posterior ethmoidal nerve
4.Anterior ethmoidal nerve
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30. 1. LONG ROOT OF CILIARY GANGLION:-
 It arises from the nasociliary nerve.
 It contains sensory fibres ,which passes through
the ganglion without synapsing and continue
on to the eyeball by means of the short ciliary
nerves.
2. LONG CILIARY NERVE :-
 There are usually 2 or 3 long ciliary nerves
branching from the nasociliary nerve. Which is
distributed to the iris and cornea.
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31. 3. POSTERIOR ETHMOIDAL NERVE :-
It passes through the posterior ethmoidal canal to be
distributed to the mucous membrane lining the posterior
ethmoidal cells and the sphenoid sinus.
4. ANTERIOR ETHMOID NERVE :-
 it passes anteriorly along the medial wall of the orbit. It
supplies the mucous membrane of the anterior ethmoid
cells and frontal sinus.
 In the upper part of nasal cavity the nerve divides into
two sets of anterior nasal branches.
1) Internal nasal branches
2) External nasal branches
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32. 1) INTERNAL NASAL BRANCHES :-
it divides into two branches.
a) Medial or Septal branches -
it supply sensory innervation of the medial septa of the nose.
b) Lateral branches :- it supplies the mucous membrane of the anterior
ends of the superior and middle nasal conchae and to the anterior lateral
wall.
2) EXTERNAL NASAL BRANCHES :-
it supplies the skin ever the tip and ala of the nose.
B. Branches arising in nasal cavity –
It supply the mucous membrane lining the nasal cavity.
C. Terminal branches of the ophthalmic division on the face -
It supply sensory fibres to the skin of the medial parts of both eyelid , the
lacrimal sac and side of the bridge of the nose.
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33. MAXILLARY DIVISION (V2)
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34. MAXILLARY NERVE
 Maxillary nerve is one of the branches of the
trigeminal nerve and is the nerve of 1st branchial
arch.it is a sensory nerve.
 It takes origin from the sensory root of trigeminal
nerve from the trigeminal ganglia.
COURSE :-
A. INTRACRANIAL COURSE :- from the trigeminal
ganglia , the maxillary division of the trigeminal nerve
becomes the maxillary nerve and passes in the middle
cranial fossa through the lateral wall of the cavernous
sinus into the foramen rotundum. It comes out into the
pterygopalatine fossa.
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35. B. EXTRACRANIAL COURSE :-
In the pterygopalatine fossa
a) It passes above the pterygopalatine ganglia and gives a
branch, <.e. sensory root of the trigeminal ganglia
which passes through the ganglia without relying in it.
b) The sensory root passes through the pterygopalatine
ganglia and gives the 3 branches.
BRANCHES :-
1. Branches In the middle cranial fossa
2. Branches in the pterygopalatine fossa
3. Other branches
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36. 1. Branches In the middle cranial fossa :-
MENINGEAL BRANCHES- supply the dura mater of middle cranial
fossa.
2 . Branches in the pterygopalatine fossa :-
It gives two sensory roots through the pterygopalatine ganglia
, which pass through it without relay and give the following
branches.
1) NASAL BRANCHES – They pass through the spheno-
palatine foramen into the nasal cavity so they are known as
sphenopalatine nerves.
A. LATERAL POSTERIOR SUPERIOR NASAL NERVES –
Supply
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37. I. Posterosuperior part or quadrant of nasal cavity
II. Superior nasal concha
III. Middle nasal concha.
B. MEDIAL POSTERIOR SUPERIOR NASAL NERVES – Supply
a)Posterior part of roof of nasal cavity.
b)Nasal septum
c. NASOPALATINE NERVE /LONG SPHENOPALATINE NERVE -
Which is the largest of this group. it passes downwards and
forwards on the nasal septum. It descends through the incisive
foramen into the hard palate and supplies the anterior part of
the hard palate.
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38. 2) PALATINI BRANCHES –
1. GREATER (anterior) PALATINE :- it passes through the greater
palatine canal and descends through the greterpalatine foramen
on the under surface of hard palate. It supplies:
a) Hard palate (except its anterior part which is supplied by
nasopalatine nerve).
b) Lateral wall of the nasal cavity of inferior nasal concha and adjoining
meatuses.
2 . LESSER OR (MIDDLE AND POSTERIOR) PALATINE NERVE :-
 it emerges through lesser palatine foramen and passes
backwards to supply.
 Soft palate for ordinary sensation as well as taste sensation.
Taste fibers come along the greater superficial petrosal nerves
which pass through the sphenopalatine ganglia.
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39. 3. PHARYNGEAL BRANCH :- it passes through the palatino-
vaginal canal and supplies Nasopharynx behind the
pharyngotympanic tube.
4. ORBITAL BRANCH :- they pass through the inferior orbital
fissure into the orbit and supply:
a) periosteum of the orbit.
b) Orbitalis muscles by the sympathetic nerve fibres, which come
along the sphenopalatine ganglia.
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40. OTHER BRANCHES
5. ZYGOMATIC NERVE :-
a) It divides into zygomaticofacial and zygomatico-
temporal nerves.
They supply the skin of the face and scalp.
b) It also carries the postganglionic parasympathetic
fibres arising from the pterygopalatine ganglia for
the supply of the lacrimal gland.
6. POSTERIOR SUPERIOR ALVEOLAR NERVE :-
it enters the posterior surface of body of maxilla and supplies
the upper three molar teeth and adjoining parts of the gums.
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41. 7. INFRAORBITAL NERVE :-
it passes through the infraorbital canal and then comes out through
the infraorbital foramen into the face.
A) In the infraorbital canal, it divides into -
a) Middle superior alveolar nerve - which supplies the premolar
teeth and maxillary sinus.
b) Anterior superior alveolar nerve - which supplies canine ,
incisor teeth and maxillary sinus.
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42. BRANCHES ON THE FACE
The infraorbital nerve emerges through the infraorbital foramen onto
the face it divide into its terminal branches.
a. INFERIOR PALPEBRAL :-
supply the skin and conjunctiva of lower eyelid.
b. EXTERNAL NASAL :-
supply the skin of the side of the nose and of the septum.
c. SUPERIOR LABIAL :-
it is the largest and most numerous, Distributed to the skin of the
upper lip and also supply to the mucous membrane of mouth and
labial glands.
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43. MANDIBULAR DIVISION (V3)
43

44. MANDIBULAR NERVE
 The mandibular division of the trigeminal nerve is the largest of the
three division, it is formed by the union of the large sensory bundle
of fibers and a small motor bundle of fibers.
 The sensory root fibers are peripheral extensions of unipolar cells
located in the semilunar ganglion.
 The motor root fibers are derived from motor cells located in the
medulla oblongata.
 The large sensory root arises from the semilunar ganglion , its fibers
are distributed to the dura, skin and the mucous membrane of the
chin, cheek and lower lip.
 The motor root is located in the middle cranial fossa ,it joins the
sensory root after it latter leaves the semilunar ganglion.
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45. BRANCHES AND DISTRIBUTION
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1. BRANCHES FROM NERVE TRUNK :-
A. NERVOUS SPINOSUS - It is a sensory nerve and ascends up.
It passes through the foramen spinosum along with middle
meningeal artery , branches of maxillary artery. Both the
nerve and artery supply the middle meningeal artery.
B. NERVE TO MEDIAL PTERYGOID – it supplies
Medial pterygoid from its deep surface. It gives a motor
root to otic ganglia but do not relay in it. then it supplies
the Tensor palatine and Tensor tympani.

46. 2. BRANCHES FROM ANTERIOR DIVISION :-
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Below the level of the undivided part of the mandibular division,
the trunk separate into two parts :
(A) ANTERIOR DIVISION – The anterior division is smaller then
the posterior division. It receives sensory and motor fiber that
supply the muscles of mastication, the skin, mucous
membrane of the cheek, buccal gingiva and lower molars. It
passes downward and forward ,where it divides into four
branches.
1. NERVE TO LATERAL PTERYGOID
2. DEEP TEMPORAL NERVE
3. MASSETERIC NERVE
4. BUCCAL NERVE

47. 1. PTERYGOID NERVE :- it supplies the lateral pterygoid
from its deep surface.
2. NERVES TO THE TEMPORAL MUSCLE :- two in
number and supply the temporalis from its deep
surface.
a. ANTERIOR DEEP TEMPORAL NERVE
b. POSTERIOR DEEP TEMPORAL NERVE
3. MASSETER NERVE :- this nerve passes above the
lateral pterygoid through the masseteric notch. The
nerve passes along with masseteric vesssels and
masseter from its deep surface.
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48. 4. BUCCAL NERVE :-
 It is a sensory nerve . It passes between the two heads of
origin of lateral pterygoid muscle and supplies the buccal
region of the face .
a) Mucous membrane of the buccal region deep to
buccinators.
b) Skin of face superficial to buccinator .
c) Lateral surface (labial surface) of the molar and
teeth.
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49. 3. BRANCHES FROM POSTERIOR DIVISION-
 It gives three sensory branches , one of which also
carries motor fibres.
1. AURICULO-TEMPORAL NERVE :- it is a sensory nerve and
ascends upwards between the neck of the mandible and
sphenomandibular ligaments. It lies lateral to spine
of the sphenoid.
 It gives a auricular branch to lateral surface of the
upper part of the auricle , tragus of the auricle and
outer surface of the tympanic membrane.
 It supplies the temporomandibular joint and skin of
the face , scalp and temporal region.
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50. 2.LINGUAL NERVE :-
It takes origin from the posterior division of the mandibular nerve
1cm below the scalp.
Courses : it passes between-
 Tensor palatii, lateral pterygoid and Medial pterygoid
 It is joined by the chorda tympani nerve 2 cm below the
skull.
 below the lower border of the lateral pterygoid ,it runs
and forward between the ramus of medial pterygoid.
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51.  Now , it comes in direct relation with the mucous
membrane covering the cusp of 3rd molar tooth of
mandible , the origins of superior constrictor and
myelohyoid .
 Then, it runs over the hyoglossus deep the
myelohyoid.
 Lastly it lies on the surface of genioglossus dep to
myelohyoid . Here, it winds round the submandibular
duct and terminates by giving its branches.
TERMINATION :-
 It terminates in sub mandibular region and gives
branches.
Its sensory fibres supplies-
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52.  Anterior 2/3rd of the tongue , Floor of the mouth and lingual
surface of gums of the teeth of mandible.
3. INFERIOR ALVEOLAR NERVE :- it is a sensory nerve for the
teeth of the lower jaw, but it also carries some motor fibres to
supply the mylohyoid and anterior belly of digastric.
ORIGIN : It takes origin from the posterior division of the
mandibular nerve.
COURSE :
 inferior alveolar nerve passes downward and forward and
comes to lie on the inner surface of the ramus of mandible
lateral to the spheno-mandibular ligament.
 It enters through the mandibular foramen ,passes in the
mandibular canal and lastly comes out in the face as the mental
nerve.
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53.  Its motor fibres separate and give a branch known as nerve to mylohyoid vessels and pierces the
spheno-mandibular ligament and then come into mylohyoid groove of inner surface of body of
mandible.
AUTONOMIC GANGLIA ASSOSIATED WITH THE MANDIBULAR DIVISION :-
two ganglia are associated with the mandibular division submandibular and otic ganglia.
A. Submandibular (submaxillary) ganglion :-
 The submandibular ganglion is a small ovoid body that is suspended from the lingual nerve .these
parasympathetic fibers are preganglionic , having their origins in the superior salivatory nucleus in the
medulla. They course within the intermediate nerve and in the facial canal and group together to
form the chorda tympani nerve.
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54. B. OTIC GANGLION :-
 The otic ganglia is a flattened ovoid body located on
medial side of the undivided mandibular division of the
trigeminal nerve. It is below the foramen ovale and
infront of the middle meningeal artery, It has two main
roots.
1. PARASYMPATHETIC PREGANGLIONIC
(SECRETORY) FIBERS :-
 These parasympathetic fibers arise in inferior salivatory
nucleus.this group of cells lies in the floor of the fourth
ventricle in the medulla.the efferent fibres pass by way
of the glossopharyngeal nerve through the jugular
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55. 2. SYMPATHETIC ROOT :-
 The sympathetic root is made up of post ganglionic fibres that have originated in the
cervical sympathetic ganglion and the plexus of the middle meningeal artery.
 These sympathetic fibres pass interruptedly through the otic ganglion With the post
ganglionic parasympathetic fibres, they join the auriculotemporal nerve and with its
branches and continue to the parotid gland.
 Affrerent or sensory fibres from the parotid gland pass by way of the auriculotemporal
55

56. CLINICAL EXAMINATION
56

57. CLINICAL EXAMINATION
The trigeminal nerve is tested for both motor and sensory functions.
1.Test for motor function – ask the patient to clench his teeth firmly
then feel the contraction of masseter muscle and observe for
deviation of the mandible as the jaws are opened. if there is 7th nerve
weakness this makes it easier to perceive deviation in to the weak side.
 Another useful indicator of the motor power of the masticatory
muscles is their ability to carry out the voluntary displacement of
the jaw against the imposed resistance of the examiner’s hand
tested as follows-
57

58.  Place the thumb on the lower molar area, with fingers externally
about the body and ramus.
 The patient moves the jaw forward ,sideways and upward, with his
or her head steadied by your other hand.
JAW JERK REFLEX :-
 Press your index finger downward and posteriorly above the mental
eminence and lightly strike the finger with a percussion hammer or
with one or two fingers of the other hand.
 A single reflex response can be discerended and the mouth shuts.
Any abnormalities of jaw jerk may indicate muscular weakness.
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59. 2. Test for sensory function :-
a) Corneal reflex - touch the periphery of the cornea with cotton wool. If
the reflex is positive the patient blinks and in any defects of the ophthalmic
division there is absent corneal reflex.
b) Pin prick sensation on the area of face supplied by trigeminal nerve –
Ask for alteration , decreased or loss of sensation in the area.
 A complete evaluation of the sensory modalities observed by branches
trigeminal nerve – pain, touch, temperature two – point discrimination,
taste should be attempted only as part of a through research
investigation.
 The following instruments, many of which can be adapted for testing of
trigeminal sensory function are available as aids in sensory evaluation :
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60. VARIOUS INSTRUMENTS used is -
60
1) Grated Frey’s hairs (a series of fine hairs or nylon fibres calibrated according to the force required to bend the filament
when it is placed against skin ,mucosa and tooth.
2) Two point esthesiometers, often designed with a pistol grip to facilitate the placement of the points of the instrument
on the oral mucosa.
3) Calibrated thermal devices for the application of hot and cold.
4) Dises of various grads of sandpaper for the evaluation of textural differences.
5) Strereognostic forms for the evaluation of oral stereo tactic ability.
6) Two – dimensional maps of the oral mucosa on which sensory response about a lesion or are of paraesthesia can be
accurately recorded.
7) Taste testing :-
Abnormality is any of there various modalities of trigeminal sensory function may be taken as evidence of an
abnormality of the affected branch of cranial nerve and provide additional evidence of the diagnosis of neuropathy
that may be suggested by the patients subjective report of paresthesia, numbness or other unusual sensations.

61. APPLIED ANATOMY
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62. APPLIED ANATOMY
1.TRIGEMINAL NEURALGIA
2.AURICULO TEMPORAL SYNDROME (FREY’S SYNDROME)
1.TRIGEMINAL NEURALGIA :-
 It is also known as tic douleureux, trifacial neuralgia and fothergill’s
disease.
 It is a paroxysmal , intermittent, excruciating pain along the
distribution of the trigeminal nerve.
TYPES :-
A) Primary or idiopathic
B) Secondary
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63. ETIOLOGY :-
1. Due to Periodontal disease and traumatogenic occlusion .
2. Due to Tumor of the cerebellar pontine angle.
3. Due to Vascular malformation
4. Idiopathic
5. Due to Atheroscleorotic blood vessel compression
6. Due to Degeneration of the ganglion
CLINICAL FEATURE :-
Age - affect older individuals of more than 50 years.
Sex - females are more affected than males.
The disease is unilateral in nearly all cases.
 Episodes of intense sharp shooting stabbing pain.
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64.  Right side of the face is affected more than the left side.
 Maxillary branch is the most commonly affected, followed by the mandibular
branch and rarely the ophthalmic branch.
PARATRIGEMINAL NEURALGIA :- In the early stages of the disease the pain
relatively mild and has been described as dull, aching or burning or resembling
a sharp toothache.
 As the attacks progress over a period of months or years they become more
severe and tend to occur at more frequent intervals.
TRIGGER ZONES :-
 Nasolabial fold, Corner of the lip, Vermilion border of the lips, ala of the nose
, the cheeks , around the eyes, eating, speaking or even exposure to wind
can trigger a painful episode.
 Patient often protect the trigger zone with their hand or an article of clothing
or they can go unshaved or unwashed for several days.
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65. DIAGNOSIS :-
 Based on history of sharp shooting pain along a branch of trigeminal nerve, precipated
by touching a trigger zone.
 Sensory or motor changes evident in patients with underlying tumors or other CNS
pathology.
 LA blocks which eliminate the trigger zones temporarily.
 MRI of the brain to rule out tumors, multiple sclerosis and vascular malformations.
DIFFERENTIAL DIAGNOSIS :-
1.Cracked tooth syndrome
2.Migrainous neuralgia
3.Sinusitis
4.Trotter’s syndrome
5.Post herpetic neuralgia
6.Trigeminal neuritis
65

66. TREATMENT
MEDICAL TREATMENT :-
 Trigeminal neuralgia is treated with carbamazepine 200 mg orally 3 or 4 times a day, which is usually
effective for long periods; it is begun at 100 mg orally twice a day, increasing the dose by 100 to 200
mg/day until pain is controlled (maximum daily dose 1200 mg).
 If carbamazepine is ineffective one of the following oral drugs can be used:
- Oxcarbazepine 150 to 300 mg B.D
- Baclofen 5 mg T.D.S
- Lamotrigine 25 mg O.D for 2 weeks.
- Gabapentin 300 mg OD on day1, 300 mg B.D on day 2, 300 mg T.D.S on day 3
- Phenytoin 100 to 200 mg B.D
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67. SURGICAL TREATMENT :-
1) Peripheral neurectomy on the nerve branch that triggers the attacks .
2) Cryosurgery
3) Injection of boiling water into the ganglion ,alcohol into the ganglion or
peripheral nerves.
4) Percutaneous radiofrequency thermoregulation at the level of gasserian
ganglion.
1. MVD(microvascular decompression) : - Under GA thumb print sized
bring opening behind the ear, neurovascular compression is alleviated by
placing a prosthesis of inert implants. Between the vessels and return to
normal pain free condition.
Complications – hearing loss, facial numbness C.S.F leak, stroke.
67

68. 2. BALLON COMPRESSION RHIZOGOMY :-
Under G.A a large caliber needle with a catheter filted with an inflated
ballon is placed to compress and mechanically injure the trigeminal
root and gasserian ganglion.(done for ophthalmic division )
Complications - small chance of causing permanent loss of sensation to
cornea.
3. GLYCEROL INJECTION :-
Under L.A spinal needle inserted beside the mouth and directed to the
space around the ganglion through foramen ovale and glycerol is
It produce a relatively middle injury to the nerve with minimal risk of
permanent facial numbness.
68

69. 2. AURICULO TEMPORAL SYNDROME(FREY’S SYNDROME) :-
 It is an unusual phenomenon which arises as a result of damage
to the auriculotemporal nerve and subsequent reinnervation of
sweat gland by parasympathetic salivary fibres.
ETIOLOGY :-
 It damage to the auriculotemporal nerve during peridectomy,
ramus resection, complications of parotitis and parotid abscess
tumor.
 After surgery when the postganglionic parasympathetic
nerves form the parotid gland are regenerating they become
mixed with the post ganglionic sympathetic fibers to the sweat
glands.
69

70. CLINICAL FEATURE :- patient will flush or seat with salivary stimulation on the involved
side of the face especially in the temporal area during eating.
TREATMENT :-
70
Non-surgical . Topical or systemic anticholinergics
. Topical antihyperhidrotics
. Low-dose radiotherapy
. Botox injection
Surgical . Partial superficial parotidectomy
. Raising a thick skin flap
. Rotation of the sternocleidomastoid muscle
. Insertion of a subcutaneous fascia
. Tympanic neurectomy

71. CONCLUSION
 The range of pathologies responsible for trigeminal neuralgia is vast and the possible topographical
areas of impairment are extensive ranging from the cervical spine to the face and skull base.
 MRI investigation is based on an initial imaging protocol that can be completed by examination if
lesions are detected.
 In this context, clinical understanding of the patient prior to the MRI scan is often a precious aid in
directing the examination (essential or secondary neuralgia, affected dermatomes).
 In the case of essential neuralgia, the most commonly observed lesion is neurovascular compression.
Diagnosis is based on T2-weighted inframillimetric acquisition by visualising a vessel perpendicular to
the REZ(root entry zone, at 2–6 mm from the emergence of the brainstem).
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72. REFERENCES
• Chaurasia’s B D human anatomy, 7th edition volume 3
• Gray’s Anatomy for students, first south asia edition
• Prasad Jagannath human anatomy 1st edition volume 3
• Bennett C.Richard Monheim’s Local anesthesia and pain control in
dental practice 7th edition.
• I.Roat Melvin, MD, FACS, Sidney Kimmel Medical College at Thomas
Jefferson University, may 2020.
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73. THANK YOU
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