trigeminal nerve : 5th cranial nerve , its course and distribution related diseases clinical implications

1. TRIGEMINAL NERVE
By: Dr. Rinshul
MDS 1st year

2. CONTENTS
 INTRODUCTION
 TRIGEMINAL NUCLEI
 FUNCTIONAL COMPONENTS
 COURSE & DISTRIBUTION
 TRIGEMINAL GANGLION
 DIVISION OF TRIGEMINAL NERVE
 CLINICAL SIGNIFICANCE
 SUMMARY
 REFERENCES

3. INTRODUCTION
 The largest cranial
nerve.
 It is mixed nerve
(sensory and motor)
 Sensory to
-skin of face.
-mucosa of cranial
viscera
-except base of
tongue and pharynx.
 Motor to
-Muscles of
mastication .
-Tensor veli palatini,
Tensor tympani.
- Anterior belly of
digastric & Mylohyoid.

4. 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 nerves.
 Axons carrying information to and from the cranial nerve form a
synapse first at these nuclei.
 Lesions occurring at these nuclei can lead to effects resembling
those seen by severing of nerves they are associated with

5. TRIGEMINAL NUCLEI
- Sensory nuclei Motor nuclei
Spinal nucleus
Relays pain and
temperature
Mesencephalic
nucleus
Proprioception
Principle
sensory
nucleus
Touch
sensation
Spinal nucleus

6. Trigeminal
ganglion
Sensory root
Touch, pressure
Pain, temp, light touch
Spinal nucleus
Principal sensory
nucleus
Proprioception
Trigeminal ganglion
Mesencephalic nucleus
CNS
• Face, scalp,
teeth,
gingiva, oral
nasal
cavities, Para
nasal sinus,
conjunctiva
and cornea
SENSORY
ROOT
FUNTIONAL COMPONENTS
carries general
somatic afferent
fibres

8. CNS
Motor
nucleus
Muscles of mastication
Masseter, lateral & medial pterygoid
temporalis
Motor root
Mandibular nerve
Tensor tympani
Tensor palatini
• Muscles of
mastication,
tensor
tympani,
tensor
palatini
MOTOR
ROOT
carries special visceral
efferent fibres

9. COURSE & DISTRIBUTION
 Both motor and sensory root are attached ventrally to junction of
pons and middle cerebellar peduncle with motor root lying
ventromedially to the sensory root .
 Pass anteriorly in middle cranial fossa to lie below tentorium cerebelli
in cavum trigeminale, here motor root lies inferior to sensory root.

10.  Sensory root connected to posteromedial concave border of the
trigeminal ganglion
 Convex anterolateral margin of the ganglion gives attachment to the
third division of the trigeminal nerve.
 Motor root turns further inferior with sensory component of V3 to
emerge out of foramen Ovale as mandibular nerve.
 Opthalmic and maxillary division emerges through superior orbital
fissure and foramen Rotundum respectively.

11. TRIGEMINAL GANGLION
 Semilunar or gasserian ganglian.
 Cresentric in shape with convexity anterolaterally.
 Contains cell bodies pseudounipolar neurons.
 Location: lies in bony fossa at apex of the petrous temporal bone
on floor of middle cranial fossa, lateral to posterior wall of
cavernous sinus.

12.  Coverings: covered by Dural poch = meckles cave or cavum trigeminale.
Cave lined by pia and arachnoid thus the ganglion is bathed in CSF.
 Arterial supply: ganglionic branches of internal carotid artery, middle
meningeal artery and accessory meningeal artery.

13. RELATIONS
SUPERIORLY
. Superior
petrosal sinus.
INFERIORLY
. Motor root
.Greater petrosal
nerve.
.Petrous apex
. Foramen
lacerum
MEDIALLY
. Posterior part of
lateral wall of
cavernous sinus.
. Internal carotid
artery with its
sympathetic
plexus.
LATERALLY
. Middle
meningeal artery
and vein
. Nervous
spinosum
. Uncus of
temporal lobe

14. DIVISIONS OF TRIGEMINAL NERVE
 Opthalmic nerve
 Maxillary nerve
 Mandibular nerve

15. OPTHALMIC NERVE
 Smallest sensory division.
 Supplies: eyeballs, conjuctiva, lacrimal gland, mucosa of nose and
paranasal sinus, skin of forehead, eyelid and nose.
 Course:
Emerges from trigeminal ganglion
Lat wall cavernous sinus
3 branches in anterior part of
cavernous sinus
Lacrimal, Nasocilliary, Frontal
Superior orbital fissure
Orbit

16. `
Thieme: Atlas of Anatomy

17. BRANCHES OF OPTHALMIC NERVE
 Lacrimal nerve
 Frontal nerve
.supraorbital
.supratrochlear
 Nasociliary nerve
. Short ciliary
. Long ciliary
. Post ethmoidal nerve
. Infratrochlear nerve
. Anterior ethmoidal

18. LACRIMAL NERVE
 Smallest
 Passes into orbit through
lateral compartment of the
superior orbital fissure.
 Receives communication
branch from Trochlear,
nerve branch of Opthalmic
and zygomaticotemporal
nerve branch of maxillary
nerve.
 Sensory to lateral
conjuctiva, upper lid,
lacrimal gland.

19. FRONTAL NERVE
 Largest
 Enters orbit through lateral part of superior orbital fissure
outside tendinous ring.
 Passes forward between roof of orbit and levator palpebral
superioris.
 Branches
1. Supratrochlear
2. Supraorbital

20. NASOCILLIARY NERVE
 Purely sensory
 Passes through medial wall of orbit between superior oblique
and medial rectus.

21. MAXILLARY NERVE
 Second division of trigeminal nerve.
 Pure sensory
 Supplies derivates of maxillary process and frontonasal process.
COURSE
Trigeminal ganglion> Middle cranial fossa
lateral wall of cavernous sinus
Foramen Rotundum
Pterigopalatine fossa
In groove on posterior surface of maxilla
Through inferior orbital fissure into orbit as INFRA ORBITAL NERVE
Through infraorbital foramen on face

23. BRANCHES OF MAXILLARY NERVE
IN MIDDLE CRANIAL FOSSA:
 Meningeal branch
IN PTERIGOPALATINE FOSSA:
 Ganglionic branches:
provides 4 set of branches:
Orbital , palatine, pharyngeal, nasal.
 Zygomatic nerve
 Posterior superior alveolar
IN THE INFRAORBITAL CANAL
 Middle superior alveolar
 Anterior superior alveolar
 Infraorbital nerve
ON FACE:
 Palpebral branches
 Nasal branches
 Superior labial branch

24. IN MIDDLE CRANIAL FOSSA:
Meningeal branch
 Supplies duramater of middle
 cranial fossa.
IN PTERIGOPALATINE
FOSSA:
 Ganglionic branches:
4 set of branches:
Orbital:
Supplies:
Periosteum of the orbit.
Palatine:
Greater palatine (anterior) Lesser palatine
(middle & posterior).
Supplies: Supplies:
Ant hard palate and bone soft palate and tonsillar
region.

25. Nasal: includes
nasopalatine branch
Supplies:
Mucosa of superior &
inferior conchae,
posterior ethmoidal
sinus and posterior
portion of nasal
septum, provides
sensation to palatal
mucosa of premaxilla
region.
Pharyngeal:
Supplies
Mucous membrane of
nasal part of pharynx,
posterior to
Eustachian tube

26. ZYGOMATIC NERVE:
It enters orbit through infra orbital fissure, divides on lat. Wall of orbit into
two:
Zygomaticofacial
nerve
- Enters face through
foramen in Zygomatic bone.
Supplies: Skin on
prominence of cheek.
Zygomaticotemporal
nerve
- Enters infratemporal region
through foramen in
Zygomatic bone.
Supplies: Skin of temporal
region, communicating
branches to lacrimal gland

27. POSTERIOR SUPERIOR ALVEOLAR NERVE
 Arises from main trunk of maxillary nerve
 Enters foramen on the posterior surface of body of maxilla
 Divides into 2 trunks:
 Supplies :
 First trunk supplies sensory innervations to Buccal gingiva in maxillary
molar region & adjacent mucosal surface.
 Second trunk supplies mucous membrane of maxillary air sinus
continuing down breaks to form superior dental plexus supplies upper
molar teeth and adjoining part of gum.

28. IN THE INFRAORBITAL CANAL
Middle
Superior
alveolar
nerve:
runs along
Lateral wall of
Maxilla.
Participates in
superior dental
plexus
Supplies :
Upper
premolars.

29. Anterior superior alveolar nerve:
Runs in infraorbital canal later anterior wall of maxillary sinus through
canal divides into two:
Dental branches
joins sup. Dental
plexus
to supply canine
& incisors of
upper jaw
Nasal branches
lat. wall of inferior
meatus to
Supply: Mucous
membrane of
lateral wall and
the floor of nasal
cavity

30. MANDIBULAR NERVE
 Largest
 Mixed
 Nerve of first brachial arch
Course
Motor root from
motor nucleus in
pons
Sensory root
Gasserian ganglion
Exits through foramen Ovale and joins to form main
trunks that lies in infratemporal fossa.
That further divides into
1. Small anterior division
2. Large posterior division

32. BRANCHES OF MANDIBULAR NERVE
 Main trunk(undivided):
 Nervous spinosus/Meningeal branch (sensory)
 Nerve to Medial pterygoid (motor)
 Anterior division:
 Massetric nerve (motor)
 Lateral pterygoid nerve (motor)
 Deep temporal nerve (motor)
 Buccal nerve (sensory)
 Posterior division:
 Auriculotemporal nerve (sensory)
 Lingual nerve (sensory)
 Inferior alveolar nerve (sensory)

33. Main
trunk:
Before dividing into
anterior and posterior
divisions it gives
branches :
1. Nervous spinosus/ meningeal
branch of mandibular nerve:
Supplies Dura matter of
middle cranial fossa and
mastoid air sinus.
2. Nerve to medial pterygoid:
Supplies medial pterygoid
Through otic ganglion
without interruption to:
Tensor tympani
Tensor palatini

34. BRANCHES OF ANTERIOR DIVISION OF
MANDIBULAR NERVE
GIVES RISE TO:
three MOTOR one SENSORY
.Massetric .Buccal nerve
.Deep temporal
.Nerve to lateral
pterygoid
Massetric: supplies masseter muscle
& TMJ.
Deep temporal: they are two in
number, supplies temporalis muscle
from its deep surface.
Nerve to lateral pterygoid: supplies
lateral pterygoid muscle.
Buccal nerve: supplies the skin and
mucous membrane of cheek.

35. BRANCHES OF POSTERIOR DIVISION OF
MANDIBULAR NERVE
 Large posterior division: goes down medial to lateral pterygoid
muscle divides into
 Auriculotemporal nerve (sensory)
 Lingual nerve (sensory)
 Inferior alveolar nerve (sensory)

36. 1. Branches of Auriculotemporal Nerve
Gives rise to three nerves:
Auricular branches:
tragus, upper auricular
region, roof of external
auditory meatus,
anteriosuperior part of
tympanic membrane.
Superficial temporal
branches:
temple of skin
Auricular
Branches &
communicating
branches:
TMJ
&
parotid

37. 2. BRANCHES OF LINGUAL NERVE:
Lies anterior to inferior alveolar and between lateral pterygoid and
tensor palatini.
Supplies: sensory to anterior 2/3 of tongue, floor of the mouth and
gingiva on lingual side of mandible.

38. 3. INFERIOR ALVEOLAR NERVE
 Largest terminal branch of mandibular nerve, mixed nerve.
 Runs vertically downwards medial to lateral pterygoid & lateroposterior to
lingual nerve, moves down between sphenomandibular ligament and
medial surface of mandibular ramus.
 Enters mandible via mandibular foramen to run in a bony canal below
teeth

39. Branches of Inferior alveolar nerve
Nerve to
mylohyoid:
Arises before
the nerve
enters the
mandibular
foramen
Supplies:
Mylohyoid
muscle &
anterior belly
of digastric
Mental nerve:
It exits canal
& divides into
3 branches
Supplies:
Skin &
mucous
membrane of
lower lip
Incisive
nerve:
It remains
within the
canal & form
plexus
Supplies:
Pulpal tissues
of incisors,
canine & 1st
premolar
Adjoining
gums
Inferior dental
plexus:
Few nerve
fibres break
away to form
plexus.
Supplies:
Molar and
premolar teeth
and adjoining
gums

42. GANGLIA ASSOCIATED WITH THE
TRIGEMINAL NERVE
CILLIARY GANGLION:
 connected with nasocilliary nerve by ganglionic branches in orbit.
 Non synaptic, sensory for orbit.
PTERYGOPALATINE GANGLION:
 Connected to maxillary nerve in infratemporal fossa.
 Sensory to orbital septum, orbicularis and nasal cavity , maxillary sinus ,
palate, nasopharynx.
OTIC GANGLION:
 Between trunk of mandibular nerve and tensor palatini, nerve to medial
pterygoid passes through but does not synapse in the ganglion.
SUBMANDIBULAR GANGLION:
 related to lingual nerve and rests on hypoglossus supplies post ganglionic
secretomotor fibres to submandibular and sublingual.

43. CLINICAL CONSIDERATION
NEURALGIA- TIC DOULOUREUX
 Unilateral severe , brief, stabbing lancinating, recurring pain in
the distribution of one or more branches of 5th nerve.
 Sharp , shooting, moderate to very severe.
 Light touch provoked, discrete trigger zones.
 Rare, in trigeminal region, each episode of pain lasts for second
to minutes, refractory period and long periods of no pain.

44. TRIGEMINAL NEUROPATHY
 Sensory loss of face or weakness of the jaw muscles.
 Includes atypical trigeminal neuralgia and atypical facial pain.
 Occurs in trigeminal area may radiate beyond
 Continuous, dull pain with sharp exacerbation
 Sensory loss, progressive vasodilatation and swelling may occur
 Causes- Sjogren’s syndrome, Herpes zoster, leprosy,
meningioma, schwanomma.

45. HERPES ZOSTER OPHTHALMICUS
 Recurrent neurocutaneous infection in Opthalmic division
of trigeminal dermatome, most freq. affecting nasociliary
branch.
 HHV3/ vericella zoster
Gasserian ganglion
Ophthalmic nerve Infraorbital nerve
Supraorbital nerve
Supratrochlear nerve

46. CAVERNOUS SINUS SYNDROME
 Cavernous sinus syndrome.
 Multiple cranial neuropathies.
 ophthalmoplegia, proptosis, ocular and conjunctival
congestion, trigeminal sensory loss V1 and V2 and Horner's
syndrome.
 Pupils may be spared or involved
 Causes: Bacterial thrombophlebitis, actinomycosis ,
rhinocerebellar mucormycosis, aspergillosis, tolosa hunt
syndrome , neoplasms, vascular lesions.

47. GRADENIGOS SYNDROME
 Petrous bone osteitis due to otitis media.
 Characterized by
Trigeminal nerve palsy
persistent otorrhea, associated with bacterial otitis media
Sixth nerve palsy (diplopia)

48. TRIGEMINAL TROPIC SYNDROME
 Trigeminal ganglion is damaged by infection or
surgery
 Causes parasthesias and anesthesia leading to
erosion of the nasal ala.

49. CONCLUSION
 Since trigeminal nerve is mixed nerve, supplies
mainly head and neck region.
 Hence as a endodontist one should know
thoroughly about intracranial and extra cranial
course, its distribution to diagnose the pathologies
associated with trigeminal nerve.

50. RELATED ARTICLES
.TRIGEMINAL NEURALGIA
(Yad Ram Yadav, Yadav Nishtha,1 Pande
Sonjjay,2 Parihar Vijay, Ratre Shailendra, and Khare
Yatin)
.Trigeminal Neuralgia and Dental Malocclusions
(G. A. S. Blair and D. S. Gordon)

51. TRIGEMINAL NEURALGIA
 Trigeminal neuralgia (TN) is a sudden, severe,
brief, stabbing, and recurrent pain within one or
more branches of the trigeminal nerve. Type 1
as intermittent and Type 2 as constant pain
represent distinct clinical, pathological, and
prognostic entities. Although multiple
mechanism involving peripheral pathologies at
root (compression or traction), and dysfunctions
of brain stem, basal ganglion, and cortical pain
modulatory mechanisms could have role,
neurovascular conflict is the most accepted
theory. Diagnosis is essentially clinically;
magnetic resonance imaging is useful to rule out
secondary causes, detect pathological changes
in affected root and neurovascular compression
(NVC).
 Carbamazepine is the drug of choice;
oxcarbazepine, baclofen, lamotrigine, phenytoin,
and topiramate are also useful. Multidrug
regimens and multidisciplinary approaches are
useful in selected patients.
 Microvascular decompression is surgical
treatment of choice in TN resistant to medical
management
 gamma knife radiosurgery, percutaneous balloon
compression, glycerol rhizotomy, and
radiofrequency thermocoagulation procedures.
Partial sensory root sectioning are rest of the
options.

52. TRIGEMINAL NEURALGIA AND DENTAL
MALOCCLUSIONS
Out of 39 patients with
intractable trigeminal
neuralgia seven have
had continuing relief for
over three years after
dental treatment. Five
out of six recent
consecutive edentulous
patients had immediate
improvement. More
radical treatment, such
as ganglion injection or
nerve root section, has
been at least
postponed.

53. REFRENCES
 Grey anatomy
 Snells anatomy
 Head and neck anatomy- BD chourasia
 Textbook of local anesthesia – Malamed
 Harrison’s principles of internal medicine