This document provides an overview of the trigeminal nerve, which is the fifth cranial nerve. It begins with an introduction to cranial nerves and then discusses the specific nuclei, ganglia, and divisions of the trigeminal nerve. The three divisions - ophthalmic, maxillary, and mandibular nerves - are described in detail regarding their course, branches, and sensory and motor functions. Key structures discussed include the trigeminal ganglion, gasserian ganglion, pterygopalatine ganglion, and submandibular ganglion. The document concludes with a recap of the main branches of the trigeminal nerve.

1. TRIGEMINAL NERVE
Guided By- DR.SHUBHRA VAISH
Presented BY – DR.Lakshay Sethi
DEPARTMENT OF PERIODONTOLGY & ORAL IMPLANTOLOGY
PG 1st Year

2. oCRANIAL NERVES AND ITS PHYSIOLOGY
oINTRODUCTION
oTRIGEMINAL NUCLEI
oCOURSE AND DISTRIBUTION
oTRIGEMINAL GANGLION
oDIVISIONS OF TRIGEMINAL NERVE
oAPPLIED ANATOMY
oEXAMINATION OF TRIGEMINAL NERVE
oCONCLUSION
oBIBLIOGRAPHY
CONTENTS

4. CRANIAL NERVES
The 12 pairs of nerves are:
I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal
VI Abducent
VII Facial
VIII Vestibulo-cochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
• There are 12 pairs of the cranial
Nerves.
• They are numbered 1 to 12 in the
craniocaudal sequence of their
attachment on the brain.

5.  It is Fifth (5th) of twelve pairs of cranial nerves.
 Also Called Trigeminus or Trifacial Nerve
 Largest Cranial Nerve
 first described by Gabriele Fallopius
 Trigeminal nerve was proposed by Jacob Benignus
Winslow
 Nerve OF 1st Branchial Arch.
INTRODUCTION

6. TRIGEMINAL NUCLEI

7. • A cranial nerve consists of motor fibres (motor nerve) or
sensory fibres (sensory nerve) or both the motor and sensory
fibres (mixed nerve).
MOTOR FIBRES SENSORY FIBRES
Somatic efferent (SE) or
general somatic efferent
(GSE)
Special visceral efferent
(SVE)
General somatic afferent
(GSA)
General visceral efferent
(GVE)
General visceral afferent
(GVA)
Special visceral afferent
(SVA)
Special Somatic Afferent
(SSA)

8. • Mixed Nerve – I.e Both
Sensory
Motor
• Sensory To -
Skin of the anterior part of
the head Oral and Nasal Cavities Teeth and the Meninges
• MOTOR TO -
Muscles of
Mastication
Anterior Belly of
Digastric
Tensor Tympani,
Tensor Veli Palatini

10. Relations :
a) Lateral – middle meningeal artery .
b) Medial – internal carotid artery, cavernous sinus .
c) Inferior – foramen lacerum, greater petrosal nerve,
motor root of trigeminal nerve .
d) Superior – parahippocampal gyrus .

11. TRIGEMINAL
GANGLION
SENSORY
GANGLIO
N
CRESCENTRIC
OR SEMI
LUNAR IN
SHAPE
LIES AT A DEPTH
OF 5CM FROM
PREAURICULAR
SITE
OCCUPIES A
SPECIAL
SPACE CALLED
DURA MATTER
TRIGEMINAL GANGLION
ARTERIAL SUPPLY:
1. Internal Carotid Artery .
2. Middle Meningeal Artery .
3. Accessory Meningeal Artery.

12.  (Semilunar Ganglion; ganglion semilunare; Gasseri; Gasserian
ganglion) occupies a cavity (cavum Meckelii) in the dura
mater covering the trigeminal impression near the apex of the
petrous part of the temporal bone.
 It is somewhat crescentic in shape, with its convexity directed
forward: medially, it is in relation with the internal carotid
artery and the posterior part of the cavernous sinus.
 The motor root runs in front of and medial to the sensory root,
and passes beneath the ganglion; it leaves the skull through
the foramen ovale, and, immediately below this foramen,
joins the mandibular nerve. The greater superficial petrosal
nerve lies also underneath the ganglion.

13. Relations
 medial: motor root of the trigeminal nerve and sphenoid bone
 lateral: posterior part of the cavernous sinus, petrous apex and petrous
segment of the internal carotid artery
 anterior: cavernous sinus and cavernous segment of the ICA
 posterior: prepontine cistern
 inferior: greater petrosal nerve and middle cranial fossa .
Blood supply
 small ganglionic branches of the cavernous portion of the ICA
 accessory meningeal artery (from the maxillary artery, via the foramen
ovale) .
Innervation
 The ganglionic epineurium is innervated by the nervus spinosus from
the mandibular division of the trigeminal nerve which re-enters the
skull via the foramen spinosum.

15. • The trigeminal nerve originates from three sensory nuclei (mesencephalic,
principal sensory, spinal nuclei of trigeminal nerve) and one motor
nucleus (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 middle cranial fossa, the sensory root expands into the trigeminal
ganglion.
• The peripheral aspect of the trigeminal ganglion gives rise to 3
divisions:
• Ophthalmic (V1),
• Maxillary (V2)
• Mandibular (V3).

16. OPTHALMIC NERVE (V1)
• First division of the trigeminal nerve
• ORIGIN –TRIGEMINAL GANGLION
• TYPE - It is a purely sensory nerve
• FUNCTION - Carries afferent stimuli of pain, light touch,
and temperature from the upper eyelids and supraorbital region of the
face, up to the vertex of the head .

17. • The ophthalmic division (V1) travels forward through the cavernous sinus
where it receives some fibers from the sympathetic plexus traveling with the
internal carotid artery
• In the sinus, the nerve is located inferior to
the trochlear nerve and lateral to the abducent and oculomotor nerves
COURSE
• Trigeminal ganglion -> cavernous sinus -> superior orbital fissure ->
lacrimal, frontal, nasociliary nerves (terminal branches) -> respective
anatomical structures

18. • It subdivides into three terminal branches
1. The Lacrimal,
2. The Frontal
3. Nasociliary Nerve

19. OVERVIEW

20. LACRIMAL NERVE
• Most lateral and thinnest branch of the ophthalmic
nerve .
• Passes into orbit through lateral compartment of the Superior
orbital fissure outside the tendinous ring .
 Connected with zygomaticotemporal branch of maxillary nerve .
secretomotor fibres to lacrimal gland
 Supplies : lacrimal gland and skin of upper eyelid and conjunctiva .

22. FRONTAL NERVE
• Is the middle and thickest branch of the ophthalmic nerve .
• It runs directly beneath the roof of the orbit and superiorly to the superior
palpebral levator muscle .
• DIVIDES Into –
1. SUPRAORBITAL – lateral branch of the frontal nerve.
-- the nerve gives off several palpebral filaments that
supply the conjuctiva and the skin of the upper eyelid.
2. SUPRATROCHLEAR -- The supratrochlear nerve is placed medial to the
supraorbital nerve.
-- Innervate the skin of the dorsum of the nose and
adjacent skin of the upper eyelid.

23. SUPRATROCHLEAR NERVE
Smaller nerve
Medial branch
Receives communication
branches from
infratrochlear nerve
Curves around
superomedial margin of
Orbit
 supplies: median
conjunctiva, Upper Lid and
lower part of forehead
Lies between frontalis and
corrugator supercilliary
muscles
SUPRAORBITAL NERVE
Larger nerve
lateral branch
Passes through
supraorbital notch
Divides in medial and
lateral branches
 Lies beneath frontalis
Muscle.
Supplies: conjunctiva,
scalp upto vertex , mucous
membrane of frontal sinus

25. NASOCILIARY NERVE
• Nerve is the medial terminal branch of the
ophthalmic nerve .
• It begins in the lateral wall of the anterior part of
the cavernous sinus .
• Crossing over the superior side of the optic nerve it
reaches the anterior ethmoid foramen, where it
divides to its own two terminal branches.

26. • Nasociliary nerve extends to the lateral branches in the following order going
from proximal to distal to the root:
1. Long Ciliary Nerve
2. Short Ciliary Nerve
3. Posterior ethmoid nerve
In the area of the anterior ethmoid foramen, the nasociliary nerve extends to its
two terminal branches:
1. Anterior Ethmoid Nerve
2. Infratrochlear nerve

28. Ciliary ganglion
• This ganglion belongs to the autonomic nervous system and
is functionally added to the ophthalmic nerve.
• Lies in posterior part of orbital cavity .
• The ciliary ganglion has preganglionic and postganglionic
fibers .

29. • Preganglionic fibers are –
1. Sensory
2. Sympathetic
3. Parasympathetic
• Postganglionic fibers :-
are the short ciliary nerves that extend forward while
grouped around the optic nerve .

30. MAXILLARY NERVE V(2)
• SECOND division of the trigeminal nerve
• ORIGIN -- Trigeminal Ganglion .
• TYPE -- It is a purely sensory nerve .
• Function – SUPPLIES
• Skin of the face over maxilla .
• Teeth of the upper jaw .
• Mucous membrane of the nose .
• The maxillary sinus and palate .

31. COURSE
• Courses forward through the lateral dural wall of the cavernous
sinus, inferiorly and laterally to the ophthalmic nerve.
• The nerve leaves the middle cranial fossa after it passes through
the foramen rotundum and enters the upper part of
the pterygopalatine fossa.
• The fibers of the maxillary nerve leave the fossa by coursing
forward through the pterygomaxillary fissure and then enter
the infratemporal fossa .

33. BRANCHES
1. Branches in middle cranial fossa
i. Meningeal branch
2. Branches arising in pterygopalatine fossa
i. Ganglionic branches
ii. Zygomatic nerve
iii. Posterior superior alveolar nerve
3. Branches arising in infraorbital groove and canal
i. Middle superior alveolar nerve
ii. Anterior superior alveolar nerve
4. Branches of infraorbital nerve in the face
i. Inferior palpebral
ii. Lateral nasal
iii. Superior labial

36. IN MIDDLE CRANIAL FOSSA:
• Meningeal branch: Travels along the middle meningeal
artery and provides sensory innervation to cranial dura
matter.

37. IN PTERIGOPALATINE FOSSA:
1. Ganglionic Branches –
Arises as 2trunks.
• Trunks join to form single root within pterygopalatine ganglion.
• Gives Orital branches,Palatine branches,Pharyngeal
branches,Nasal branches
• Gives postganglionic secretomotor fibers to lacrimal gland
via zygomaticotemporal and lacrimal.
2. Orbital branch: Supplies periosteum of orbit

38. • Nasal branch --
• Supplies to mucosa of superior and inferior conchae,
posterior ethmiodal sinus and posterior portion of nasal
septum. It also includes Nasopalatine branch .

39. B. . ZYGOMATIC NERVE
• It enters the orbit through inferior orbital fissure and runs forward
along its lateral wall .
• Divides into 2 branches :
i. Zygomaticotemporal nerve :
emerges from the temporal surface of the bone
supplies the skin over temple region.
ii. Zygomaticofacial nerve :
emerges from the bone through the zygomaticofacial foramen
present on the lateral surface of the bone
Supplies skin of cheek

40. BRANCHES OF INFRAORBITAL NERVE ON FACE
INFRAORBITAL NERVE
INFERIOR
PALPEBRAL
Supply lower
eyelid
LATERAL NASAL
Supply the skin
on lateral side
of nose
SUPERIOR LABIAL
Supply skin of
upper lip and part
of the cheek

42. Pterygopalatine Ganglion
Largest peripheral ganglion of parasympathetic system
Topographically = maxillary nerve
Functionally = greater petrosal branch of facial nerve
Situation :
i. Lateral to sphenopalatine foramen
ii. Below the
maxillary nerve .
iii. Front of
pterygoid canal .

43. Pterygopalatine Fossa
• The body of the ganglion rests in
the pterygopalatine fossa. The
pterygopalatine fossa is a
depression that lies within the
pterygomaxillary fissure, inferior to
the sphenopalatine foramen.
• This fissure is a natural furrow
that is formed between the
posterosuperior border of
the maxilla and the anterosuperior
border of the pterygoid plates.

44. MANDIBULAR NERVE V3
• THIRD DIVISION OF TRIGEMINAL NERVE
• TYPE -- both sensory and motor.
• SUPPLY --
• Buccal skin
• anterior two-thirds of the tongue,
• temporal region;
• mastication muscles, mylohyoid muscle
• anterior belly of the digastric muscle

45. • Formed by union of two roots .
• Sensory root arises from lateral part of trigeminal
ganglion – leaves the skull through foramen ovale .
• Motor root passes through foramen ovale and unites
with the sensory root just below the foramen .
• Nerve then enters the infratemporal fossa
• After a short downward course, it then divides into a
smaller anterior division and a large posterior division

46. BRANCHES

47. SENSORY SUPPLY OF V3
1. Dura
2. Skin
3. Mucous membrane of lower lip, cheek and chin
4. External ear
5. Parotid gland
6. TMJ
7. Scalp over the temporal bone
8. Lower teeth and gingiva
9. Anterior 2/3rd of tongue

48. MOTOR SUPPLY OF V3
1. Muscles of mastication
2. Mylohyoid
3. Anterior belly of digastric
4. Tensor tympani
5. Tensor veli palatini

50. 1. Auricular branch
2. Articular branch
3. Superficial temporal
nerve
4. Communicating
branches

52. SUBMANDIBULAR GANGLION
The submandibular ganglion is
one of four parasympathetic
ganglia of the head and neck. It
receives parasympathetic fibers
from the facial nerve .
Gross anatomy
• Small ganglion suspended from
the undersurface of the lingual
nerve.
• Inferior to submandibular
duct sitting on the hyoglossus
muscle .
• Supplies secretomotor fibers to
the sublingual and submandibu
lar salivary glands .

53. • Preganglionic parasympathetic fibers derived from the chorda tympani travel in
the lingual nerve and synapse in the submandibular ganglion.
• Some of the postganglionic secretory fibers enter the submandibular gland;
others, by entering the lingual nerve, reach the sublingual gland.
• Postganglionic sympathetic fibers (from the superior cervical ganglion) pass
through the submandibular ganglion and are distributed with the
parasympathetic fibers.
Roots
Branches
Lingual Nerve

55. TRIGEMINAL
NERVE
OPTHALMIC
NERVE
MAXILLARY NERVE MANDIBULAR
NERVE
FRONTAL
LACRIMAL
NASOCILLIARY
Buccal Nerve
Superior alveolar nerve
Middle meningeal nerve
Infraorbital nerve
Zygomatic nerve
Auriculotemporal Nerve
Pharyngeal nerve
Nasopalatine nerve
Inferior Alveolar
Nerve
Lingual Nerve
RECAP

56. To be able to distinguish and to cure with some degree of certainty, a disease
that
during the time it lasts is extremely excruciating is an addition, however small,
to John Fothergill (1712–80)

57. 1. Referred pain
2. Mandibular neuralgia .
3. Lesion at foramen ovale .
4. Lingual nerve damage .
5. Referred pain in the ear
CONTENTS

58. EXAMINATION OF TRIGEMINAL NERVE
1. SENSORY
FUNCTION
2. MOTOR
FUNCTION
3. CORNEAL
REFLEX
4. JAW JERK TEST

59. SENSORY
FUNCTION
•Initially test the sensory branches by lightly touching the face with a piece of
cotton wool followed by a blunt pin in three places on each side of the face:
1.Around the jawline
2. on the cheek
3. on the forehead
1 2
3

60. MOTOR FUNCTION
• Inspect for wasting of the temporal and masseter muscles.
• Ask patient to clench their teeth and palpate for contraction of the
temporal and masseter muscles.
• Ask the patient then to open their mouth against resistance

61. CORNEAL REFLEX
Ask the patient to look up and away, touch the cornea .
Reflex blinking of both eyes is a normal response.

62. JAWJERK TEST
• Ask the patient to open the mouth fully, and close halfway, place
index finger on the chin and tap with a patella hammer.
• When it is normal, tapping the mandible produces a brisk
contraction.

63. Mechanisms OF Injury to
TRIGEMINAL NERVE
1. Local anaesthetic injection
2. Third molar surgery
3. Maxillofacial trauma
4. Orthognathic surgery
5. Maxillofacial pathology
6. Endodontic and chemical injury

64. LOCAL ANESTHETIC SOLUTION
Incidence – between 1:26,762 and 1:160,571
Harn and Durham – 1990 – transient sensory disturbance – 3.62%
Causes :
i. Direct penetration of the nerve by needle
ii. Hematoma formation from vessel laceration
iii. Direct laceration of the nerve from a barb on the tip of needle
after repeated injections.
iv. Needle contact with cortical bone.
v. Chemical injury from intraneural injection.

65. Maxillofacial Trauma
• Neurosensory impairment due to trauma – 70.9%
• Neurosensory alterations caused by – laceration,
traction or compression of the IAN from bony
segment displacement
• Reduction of fractures with alignment of segments
and removal of loose bony segments that impinge on
nerve will assist in spontaneous neurosensory
recovery .

66. Orthognathic surgery
• During SSO, nerves could be injured at various locations
• Incidence of neurosensory alterations during mandibular
orthognathic surgery has been found to increase with
intraoperative complications .
• During maxillary or mid face procedures, ION is at risk
for injury because of soft tissue flap retraction .

67. Maxillofacial Pathology
Causes – Odontogenic and non-odontogenic benign cysts and tumors .

68. Endodontic and Chemical Injury

69. CLINICAL CONSIDERATIONS
• Trigeminal neuralgia
• Herpes Zoster
• Ophthalmicus
• Trigeminal
neuropathy.
• Wallenberg syndrome.

70. Trigeminal Neuralgia (Fothergills Disease)
or
Tic Douloreux)
• Trigeminal neuralgia is defined as sudden, usually unilateral,
severe, brief, stabbing, lancinating, paroxysmal, recurring pain
in the distribution of one or more branches of 5th cranial nerve
.
• John Locke – 1677 – first full description with its treatment.
• Nicholas Andre – 1756 – Tic Douloureux (painful jerking)
• John Fothergill – 1773 – published detailed description of TN,
thus, Fothergill’s disease .

71. Etiology : Unknown ; idiopathic .
1. Dental etiology
2. Infections – granulomatous (sarcoidosis) and non –
granulomatous infections .
3. Multiple sclerosis .
4. Petrous ridge compression .
5. Post traumatic neuralgia .
6. Intracranial tumors .
7. Intracranial vascular abnormalities .
8. Viral etiology – postherpetic neuralgia .

72. GENERAL CHARACTERISTICS
 Incidence : rare
 Age : 5th or 6th decade
 Sex predilection : female predisposition (58%)
 Affliction for side : right side (60%)
 Trigeminal nerve involvement : V3>V2>V1

73. Clinical Features :
Refractory period can be as short as a couple of seconds
With each attack, pain seems to become more intense and
unbearable
Pain rarely crosses midline.
Pain is of short duration & lasts for a few seconds
extreme cases – frozen or mask like face .
different stimuli can elicit pain :
i. Touching or applying heat or cold to the cheek or gum
ii. Chewing, yawning or talking
iii. Wind blowing on face
iv. Gustatory stimuli and vibration
v. Smiling / brushing / shaving / washing face

74. Diagnosis – Imaging
1. CT scan – poor resolution in posterior
fossa.
2. MRI – imaging modality of choice;
reveal MS plaques and pontine
gliomas
.
1. Conventional angiogram – useful
only to detect vascular malformation
.

75. SWEET DIAGNOSTIC CRITERIA
1. Pain is PAROXYSMAL
2. Pain is provoked by light touch to the face
3. Pain is confined to trigeminal distribution
4. Pain is unilateral
5. Clinical sensory examination is normal

76. MEDICAL TREATMENT
• First line of approach
• TN does not respond to analgesics
1. Carbamazepine is used as a standard drug. Adult dose 100mg,
thrice daily initially.
• Started as small dose & gradually increased to prevent side
effects.
ADVERSE EFFECTS -- include dizziness, ataxia, vertigo, skin rashes etc
When carbamazepine is contraindicated, clonazepam 1.5mg/day
can be used
2. Phenytoin Sodium
usually used in combination of carbamazepine
100mg thrice a day
side effects: gum hyperplasia, swelling of lymph glands
3. Gabapentin
300mg/day
used with caution in patients with renal & hepatic disease
4. Gaba agonist
these drugs reduce the central projection of painful impulses
eg. Baclofen , adult dose being 5-10 mg TDS.

77. 1. Peripheral nerve injections
a) Long acting anesthetic agents without
adrenaline (bupivacaine)
b) Alcohol block - 0.5 -2ml of 95% absolute
alcohol.
2. Peripheral neurectomy
 oldest and most effective
Acts by interrupting the flow of afferent
impulses to central trigeminal apparatus
3. Cryotherapy or Cryoneurolysis
Direct applications of cryotherapy probe
at temperatures colder than -60 degrees
Celsius .
In this the nerve is not sectioned but
destroyed
4. Peripheral radiofrequency neurolysis
(thermocoagulation)
Gregg and Small (1986)
Radiofrequency electrode has the
capacity to destroy the pain fibres

78. • 5 Gasserian ganglion procedures
• Glycerol injection
• thermocoagulation
• Balloon compression
• 6.
• Open procedures (intracranial procedures)
 microvascular decompression of sensory root .
1967-1976 by Jannetta
 most commonly performed intracranial open
procedure .
 open craniotomy approach is used to gain
access to the trigeminal root entry zone and
adjacent brain stem
Compressing branch of superior cerebellar
artery is carefully separated from the nerve
.

79. • Ophthalmic zoster is a disease characterised by
reactivation of varicella zoster virus that is inactive in
dorsal root or cranial root ganglion, after primary infection
Oral and facial lesions result from HZ of 2nd and 3rd divisions
of trigeminal nerve, but involvement of 1st division is
considerably more common esp. nasociliary nerve
HZ has been associated with dental anomalies and severe
scarring of facial skin when trigeminal HZ occurs during tooth
formation
HERPES ZOSTER OPHTHALMICUS

80. • Diagnosis :
 history of pain.
 unilateral nature .
 Segmental distribution of
lesions.
 vesicles are present.

81. Treatment :
• Acyclovir 800mg, 5 times/day for a week,
within 4 days of onset of rash
• Valacyclovir 1,000mg, 3times/day for a week
• Analgesics
• Antibiotic ointments
• Systemic steroids 60mg/day
• Corneal grafting

82. TRIGEMINAL NEUROPATHY
• Characterized by numbness in the skin or
mucosal membranes in the distribution of the
trigeminal nerve Neuropathic weakness in the
muscles of mastication.
• TNO should not be confused with trigeminal
neuralgia (TNA)
• Brief attacks of lancinating pain but without
sensory impairment or motor weakness.

83. • In TNO, pain may dominate the clinical picture
• As disorder progresses and neurons are destroyed,
numbness and weakness usually appear.
• In untreated idiopathic TNA, neurons are preserved,
although their myelin sheaths may be destroyed and there
is ultimately gain of function.
• In TNO as the condition advances, loss of function in the
affected nerve branches becomes evident .

84. Wallenberg syndrome
Neurological disorder causing a range of
symptoms due to ischemia in the lateral
part of the medulla oblongata in
the brainstem.
The ischemia is a result of a blockage in
the posterior inferior cerebellar artery or
one of its branches.
Wallenberg syndrome is also called
Lateral medullary syndrome, posterior
inferior cerebellar artery syndrome and
Vertebral artery syndrome

85. CAUSE
Occlusion of the posterior inferior cerebellar artery or one of
its branches or of the vertebral artery, in which the lateral part
of the medulla oblongata infarcts, resulting in a typical
pattern.
DIAGNOSIS
Diagnosis is usually done by assessing vestibular-related
symptoms in order to determine where in the medulla that
the infarction has occurred.
Head Impulsive Nystagmus Test of Skew (HINTS)
examination of oculomotor function
Computed tomography (CT)
Magnetic resonance imaging (MRI) to assist in stroke
detection

86. • Treatment involves focusing on relief of symptoms and
active rehabilitation
Speech Therapy - common form of rehabilitation
In more severe cases, a feeding tube maybe inserted through
the mouth or a gastrostomy may be necessary if swallowing is
impaired.
Medication may be used to reduce or eliminate residual pain -
anti-epileptics such as gabapentin. Antiplatelets like aspirin or
clopidogrel and statin regimen. Warfarin is used if atrial fibrillation is
present.
• One of the most unusual and difficult to treat - violent hiccups.
struggle to eat
sleep
carry on conversations
Unfortunately there are very few successful medications
available to mediate the inconvenience of constant hiccups.
Treatment for this disorder can be disconcerting because some
individuals will always have residual symptoms due to the severity of
the blockage as well as the location of the infarction.

88. • Nerve blocks .
• Flap retraction during
periodontal surgery .
• Implant surgery .
• Maxillary sinus surgery .

90. Photograph showing the osteology involved in an inferior
alveolar nerve
injection and an inset showing an actual injection .

91. Flap retraction During Surgery

92. Dental Implant Surgery
Dent Update. 2010 Jul-Aug;37(6):350-2, 354-6, 358-60 passim

93. A = the orthopantomograph, B and C = cone beam
computed tomography shows full dental implant
intrusion into mandibular canal in 35 jaw dental
segment region. There is direct mechanical
trauma - IAN transection.

94. In a recent study, Kim et al classified the buccolingual location of IAN
into 3 types :
1. Type 1 (70%) : IAN canal follows the lingual cortical plate of the
mandibular ramus and body
2. Type 2 (15%) : IAN canal is located in the middle of the mandibular
ramus posterior to the second molar. It then runs lingually to follow
the lingual plate
3. Type 3 (15%) : IAN canal is located near the middle of the ramus
and body
Bifid canal
i. Nortje et al – 0.9%
ii. Grover et al – 0.08% of radiographs suggestive of bifurcation
of IAN
iii. Langlais et al – 0.95% cases had bifid canals

95. Maxillary sinus surgery

96. Treatment Approaches
FACTORS DECIDING THE MOST
APPROPRIATE SURGICAL
APPROACH
1. PATIENT’S ANATOMY
2. SURGEON’S EXPERIENCE
3. MECHANISM OF INJURY
4. LOCATION OF INJURY

97. APPROACHES FOR DIFFERENT NERVES
LINGUAL NERVE
Approached intraorally via a paralingual or lingual gingival
sulcus incision
INFERIOR ALVEOLAR NERVE
 vestibular incision with identification of MN and lateral
decortication to expose a portion of IAN
 in cases of limited mouth opening, extraoral approach
applied
 IAN is approached via lateral decortication techniques
INFRAORBITAL NERVE
 transorally via a maxillary vestibular incision at the time of
maxillary or zygomaticomaxillary complex fracture repair

98. Outcomes of Trigeminal Nerve
injuries and Surgical Intervention .
• Injury to trigeminal nerve maybe associated with impairment of
speech, taste, mastication and impact on quality of life.
• Based on recent studies, success of microneurosurgical
reconstruction of the TN injuries could be estimated to be between
30% and 50% for all degrees of injury and types of reconstruction.
• Gap repair with an autogenous sural nerve graft may provide a
better outcome because the graft itself provides a rich source of
Schwann cells and neurotropic and neurotrophic factors that assist
in the degeneration and regeneration process of neural recovery.

99. CONCLUSION
Since Trigeminal nerve is a mixed nerve and supplies mainly head and
neck region, one should know thoroughly about its cranial and
extracranial course and distribution, to diagnose the pathologies
associated with nerve and for appropriate treatment .

100. BIBLIOGRAPHY
• Anatomy for dental students – Inderbir Singh
• Grant’s Atlas of Anatomy – 10th edition
• Atlas of Human Anatomy 5th edition – Frank H.
Netter
• The Clinical Anatomy Of Cranial Nerves – Joel A.
Vilenski
• Anand’s Human Anatomy for dental students 2nd
edition
• Textbook of oral and maxillofacial surgery – Balaji
2007 edition
• Essentials of Human Anatomy – A.K. Datta
• Monheim’s Local Anaesthesia and Pain Control in
Dental Practice - 7th edition
• Oral and Maxillofacial Trauma – Fonseca – 4th
Edition
• Handbook of Local Anesthesia - Malamed

101. • Inderbir Singh’s Human Embryology, 11th edition
• BD Charausia , 6th edition
• Textbook of anatomy, Vishram Singh, vol III, 2nd
edition
• Textbook of oral medicine, oral diagnosis and oral
radiology – Ravikiran Ongole, 2nd edition
• Burket’s oral medicine and diagnosis – 9th edition
•
• Textbook of oral and maxillofacial surgery, Neelima
Malik, 3rd edition