anatomy of trigeminal nerve and its applied anatomy

1. The trigeminal nerve
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GUIDED BY:
DR RAMESH TR
PRESENTED BY:
DR BHAKTI PATEL
MDS( PROSTHO -1ST YEAR )

2.  Introduction to nervous system
 Introduction to trigeminal nerve
 Origin
 Trigeminal Nuclei
 Divisions of Trigeminal Nerve
 Applied Anatomy
 References
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3. 3
NERVOUS
SYSTEM
CNS
BRAIN SPINALCORD
PNS
MOTOR
NEURONS
SENSORY
NEURONS
RECEIVES AND
PROCESSES SENSORY
INFORMATION
CONDUCTS THE
SIGNALS TO BRAIN
AND FROM BRAIN
CONDUCTS THE
SIGNAL CNS TO
MUSCLE
CONDUCTS THE
SIGNAL SENSORY
ORGANS TO CNS

4. 4

5.  12 in number
1. Olfactory nerve(s)
2. Optic(s)
3. Occulomotor(m)
4. Trochlear(m)
5. Trigeminal(mixed)
6. Abducent(m)
7. Facial(m)
8. Vestibulo-cochlear(s)
9. Glossopharyngeal(mixed)
10. Vagus(mixed)
11. Accessory(m)
12. Hypoglossal(m)
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6.  Trigeminal nerve is 5th cranial nerve.
 It is largest cranial nerve.
 It is a mixed nerve .
 Nerve of 1st brachial arch.
 Composed of small motor and considerably large sensory
root.
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7. 1. superior sensory nucleus: in posterior
part of pons and lateral to motor nucleus.
2. Spinal nucleus: continuous inferiorly with
the main sensory nucleus in the pons and
extends inferiorly through length of the
medulla oblongata.
3. Mesencephalic nucleus: situated in
midbrain
4. Motor nucleus: extendes from pons to
midbrain.
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8.  Crescent in shape – it is called semilunar ganglion.
 Location – in the Meckel’s cavity, on the anterior surface of
the petrous part of temporal bone.
 Measurement- 1.0 2.0 cm (approx)
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9. Sensory to
• Skin of entire face
• oral cavity except of pharynx and base of tongue
• Mucosa of cranial viscera
Motor to
• Muscles of Mastication
• Tensor veli palatini, Tensor tympani
• Anterior belly of digastric
• Mylohyoid
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10. SENSORY ROOT
 The fibers arise from the semilunar/gasserian ganglion .
 It is located in the Meckel’s cavity .
 Lies in Pons lateral to Motor nucleus.
 It forms the central and the peripheral processes.
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11. Sensoryroot
Central branch
Ascending
fibers
Superior
salivary nucleus
Descending
fibers
Spinal nucleus
Peripheral
branch
Opthalmic
Maxillary
Mandibular
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12. Motor nucleus in upper pons.
Motor root passes below
the foramen ovale and
joins with sensory root of
mandibular division
Muscles of
mastication
Tensor veli
palatini
Tensor
tympani Mylohyoid
Anterior belly
diagastric
At trigeminal ganglion it goes
inferio laterally
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MOTOR ROOT

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14. OPHTHALMIC NERVE
 Supplies : eyeballs, conjunctiva, lacrimal gland, scalp, skin of forehead, and eyelids
 In the middle cranial fossa its branches supply the dura MATTER.
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15. 3 branches in ant part of cavernous sinus
superior orbital fissure
Lateral wall of cavernous sinus
orbit
lacrimal, nasocilliary, frontal
emerges from trigeminal ganglion in middle cranial fossa
15 COURSE:

16. OPTHALMIC
NERVE FRONTAL
SUPRAORBITAL
SUPRATROCHLEAR
NASOCILIARY
SHORT CILIARY
LONG CILIARY
ANTERIOR
ETHAMOID
LACRIMAL16

17. LACRIMAL
NERVE
17
It supplies the sensory fibers
to the lacrimal gland
Courses anterolaterally to
reach the lacrimal gland
Leaves the cranium through
Superior orbital fissure

18. FRONTAL NERVE18
Divides into :
Passes forward between roof of orbit and Levator Palpebral
Superioris
Enters orbit through lateral part of superior orbital fissure outside
tendinous ring
Supratrochlear Nerve Supraorbital Nerve
Skin of upper eyelid, medial portion of forehead. Supplies skin of forehead and anterior scalp
upto vertex of skull.

19. NASOCILLIARY
NERVE
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Gives branches in orbit, nasal cavity
and on the face
Runs along medial wall of orbit between
Superior Oblique and Medial Rectus
Passes through middle part of superior
orbital fissure
(Purely Sensory)

20. NASOCILIARY NERVE
IN NASAL CAVITY
BRANCHES IN ORBIT
SHORT CILIARY
LONG CILIARY
ANTERIOR
ETHAMOIDAL
POSTERIOR
ETHAMOIDAL
ON FACE20

21. Branches in the orbit
 Short Ciliary Nerves and Long Cilliary Nerves :supply to Iris and Cornea.
 Post Ethmoidal Nerve: mucous membrane lining the ethmoidal sinus and the sphenoidal sinus.
 Ant. Ethmoidal nerve: it supplies to mucous membrane of ant. Ethmoidal sinus and frontal sinus.
It gives of NASAL branches which supply septum, superior and middle nasal conchea and skin
over the ala of nose and tip of nose.
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Terminal branches on the face:
sensory to eyelids and lacrimal sac
Branches in nasal cavity:
supply the mucosal lining of nasal cavity

22. MAXILLARY NERVE22

23. COURSE:23
Through infraorbital foramen on face
Through inferior orbital fissure into orbit as INFRA ORBITAL
posterior surface of maxilla
Pterigopalatine fossa
foramen rotundum
gives off meningeal branches in Middle cranial fossa
Middle part of Trigeminal ganglion

24. BRANCHES24
IN MIDDLE CRANIAL FOSSA ON FACEINFRAORBITAL
CANAL
PTERYGOPALATINE
FOSSA

25. IN MIDDLE CRANIAL FOSSA:
Meningeal branch: Travels along the middle meningeal artery and provides
sensory innervation to cranial dura matter.
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26. IN PTERIGOPALATINE FOSSA:
Zygomatic nerve:
1)zygomaticotemporal : sensory innervation to
the skin on the side of the forehead
2)zygomaticofacial: skin on the prominence of
the cheek.
Pterygopalatine nerve:
1) orbital branches: periosteum of orbit
2)nasal branches: mucous membrane of
superior& middle conchae, post. Portion of
nasal septum, lining of the post. Ethemoidal
sinus.
3)palatine branches: greater & lesser palatine
nerves
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27. 27
 Posterior superior alveolar nerve:
it arises from the main trunk of maxillary nerve in
the pterygopalatine fossa
Usually arises as 2 trunks.
1st trunk continues downwards on posterior
surface of maxilla
Innervation: buccal gingiva in maxillary molar region
and adjacent facial mucosal surface
2nd trunk enters maxilla through PSA canal to
travel to posterolateral wall of maxillary sinus
Innervation: sinus mucosa, PDL, pulp of molar tooth.
1 ST
TRUNK
2 ND
TRUNK

28. IN THE INFRAORBITAL
CANAL
1.Middle superior alveolar nerve:
 Supplies the adjacent mucosa of
maxillary sinus, two premolars &
mesiobuccal root of first molar
2. Anterior superior alveolar nerve:
 supplies the central and lateral incisors
and cuspids and the labial mucosa.
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29. FACIAL BRANCHES
1.palpebrae branches-pierces Orbicularis Occuli
and supplies skin of lower lid.
2.Nasal branches-supplies skin of lat wall nose and
mobile part of septum.
3. Superior labial nerve-
supplies skin and mucous membrane of upper lip,
cheek and labial glands
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30. MANDIBULARNERVE30

31. Mixed-large sensory and small motor
Nerve of 1st branchial arch
Motor root- from motor nucleus in
Medulla oblongata
Sensory root- Semilunar ganglion
small ant. Division
exit through foramen ovale .
They unite outside of the skull and forms main trunk.
Trunk remains undivied for only 2 to 3 mm
large post. division
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32. Branches
 Trunk (undivided)
 Nervous Spinosus
 Nerve to medial Pterygoid
 Anterior Division
 Massetric Nerve.
 Deep temporal Nerve.
 Nerve to lateral Pterygoid
 Buccal Nerve.
 Posterior Division
 Auriculo Temporal Nerve
 Inferior. Alveolar Nerve
 Lingual Nerve.
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33. Branches from trunk
 Before dividing into anterior and posterior division it gives 2 branches during its 2-3mm path
1.Nervous spinosus or Meningeal branch of Mandibular nerve
 It reenters cranial cavity through foramen spinosum along with middle meningial artery
 Supply: Dura mater of middle cranial fossa and mastoid air sinus
2.Nerve to medial Pterygoid
 Supplies medial pterygoid
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34. Branches from the anterior division
 After dividing from the main trunk. It runs anteriorly and below the lateral pterygoid
muscle to over its upper border.
 After this the nerve is buccal nerve. reach its external surface of muscle by passing
through two heads
1.Nerve to lateral pterygoid: It enters the deep surface of the muscle. It may
arise as independent branch or may arise in common with buccal nerve.
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35. 2.Massetric nerve- Emerges at the upper border of the lateral pterygoid just in front of TMJ.
Passes laterally through mandibular notch along with massetric vessels, and enters the deep
surface of masseter, also supplies TMJ
3.Buccal nerve-is the only sensory branch of ant div. travels between 2 heads of lat
pterygoid and emerges in cheek at ant border of masseter at the level of occlusal plane of
2nd and 3rd molars . Supplies mm and skin of cheek.
4.Deep temporal nerve- There are anterior and posterior deep temporal nerves which
supplies the ant and post. portions of Temporal muscles.
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36. Branches Of Posterior
Division
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1)Auriculo temporal nerve
Arises from 2 roots which run backwards and encircle the
middle meningeal artery and form single trunk
The trunk passes posterior to lateral pterygoid between neck of
mandible and sphenomandibular ligament superior to 1st part
of maxillary art.
Lies behind the TMJ close to the parotid
Ascends behind superficial temporal vessels and then in
temporal region divides into superficial temporal branches.

37. 37
Branches Of Auriculotemporal Nerve
 Auricular branches- supply tragus and helix (fleshy ridge of the pinna)
 Superficial temporal branches-supply skin of temple. It also supply sensory
and secretomotor to parotid.
 Articular branches-supply the TMJ

38. 2. INFERIOR ALVEOLAR NERVE:
• Runs vertically downwards medial to lateral pterygoid and lateroposterior
to lingual nerve. Then moves between the sphenomandibular ligament
and medial surface of mandibular ramus.
• Enters mandible in pterygoidmandibular space through mandibular
foramen to run in a bony canal below the teeth
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39. Branches:
1.Mylohyoid: Supplies to mylohyoid muscle and anterior belly of digastric. It is also
sensory to skin on inferior and anterior surfaces of mental protuberence. It may
provide sensory innervation to mandibular incisors. There is also evidence that
mylohyoid supply to mesial root of mandibular first molar.
2.Mental nerve : innervates skin of chin and skin and mucous membrane of the lower
lip.
3.Incisive nerve : innervates pulpal tissue of canine and incisors through dental
branches.
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40. IANB (TECHNIQUE)
 25 gauge needle
 Landmarks: coronoid notch,
pterygomandibular raphe
occlusal plane of the mandibular posterior teeth
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42. LINGUAL NERVE
 Sensory tract to anrerior 2/3rd of tongue
 Provide both general sensation and gustation (taste) senstion for
this region.
 It is the nerve that supplies fibre for general sensation, whereas
chorda tympani supplies fibre for taste.
 also sensory to mucous membrane of floor of mouth
 Most commonly associated with paresthasia.
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43. APPLIED ANATOMY
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44. TRIGEMINAL NEURALGIA – TIC DOULOUREUX
Sudden, usually unilateral, severe, brief, stabbing
lancinating, recurring pain in the distribution of one or
more branches of the 5th Nerve
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45. GENERAL CHARACTERISTIC
o Incidence- rare affliction, 4 in 1million person
o Age of occurrence - late middle age ( 5th & 6th decade)
o Predilection- female (58%)
o Affliction for side - right side ( 60%)
o Division more involve- v3
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46.  CLINICAL CHARACTERISTIC
o TN typically manifests sudden, sharp, unilateral, lancinating, shock like pain elicited by
slight touching superficial trigger points
o TRIGGER POINTS
1. V1- supraorbital ridge
2. V2- skin of upper lip,
ala nasi, upper gums
3. V3- lower lip, teeth or gums
of lower jaw,
tongue rarely involved
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47. o Pain is ipsilateral to lesion.
o Usually confined to one part of one division
o Extreme case patient will have motionless face - frozen
or mask like face
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48. DIAGNOSTIC 5 MAJOR CRITERIA
o pain is paroxysmal
o Pain may be provoked by light touch to the face
o Pain is confined to trigeminal distribution
o Unilateral
o Clinical sensory examination is normal
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49. TREATMENT
 MEDICAL:
1. Intramuscular morphine
2. Triochloroethylene
3. Diphenylhydantoin sodium
4. Carbamazepine
 SURGICAL
1. Alcohol blockade at gasserian ganglion
2. Intracranial nerve decompression
3. Peripheral neuractomy
 NEWER APPROACH - acupuncture
 PSYCHOLOGICAL APPROACH- psychiatric counselling
hypnosis
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50.  As prosthodontists we should treat the patient of trigeminal
neuralgia with specific care.
 Patient should be informed and consent should be taken.
 During all the procedures trigger points should not be touched.
 Patient should take drugs properly on time.
 If there is still extreme pain episodes, laser treatment should be
considered because it improves oxygenation so it will help in
treatment.
PROSTHODONTIC CONSIDERATION50

51. REVIEWS
Sub-occipital craniotomy to find and resolve the
underlying trigeminal nerve compression.One
prospective study found that 92.5% of patients were
pain free without medication at average 28 month
follow-up. So it is advisable to undergo this procedure
before dental treatment.
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Surgical Treatment of Trigeminal Neuralgia by Sarah K.B.
Bick et al, in 2017 Neurosurg Clin N Am

52. There are many studies going on to know the role of nerve blocks in the diagnosis
and treatment of trigeminal neuralgia. According to one study nerve blocks are very
accurate method to confirm the diagnosis but for treatment it is still under research
.In general, blocks are well tolerated with least side effects, so it is very well
accepted.
52
Nerve Block for the Treatment of Headaches and Cranial
Neuralgias – A Practical Approach by Fabíola Dach et al in 2015
published in journal of American Headache Society

53. Reference:
Grey’s anatomy
Head and Neck Anatomy-BD Chaurasia
Textbook of Oral and Maxillofacial surgery–Neelima
Anil Malik
Textbook of Local Anesthesia-Stenly F Malamed
Monheim’s LOCAL ANESTHESIA AND PAIN CONTROL
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