Trigeminal nerve

1. Trigeminal Nerve
- Dr . Arun Divakar Sankar
1st Year Post Graduate
Department Of Oral And Maxillofacial Surgery

2. INTRODUCTION
• The largest cranial nerve
• It is the 5th cranial Nerve
• It is mixed nerve
( sensory and motor )
The trigeminal nerve is the primary sensory neuron supplying the head
and neck, and its branches are never far from the operating field of the
oral and maxillofacial surgeon.

3. THE TRIGEMINAL SYSTEM
• Nucleus
• Root
• Ganglion
• Nerve

4. What is
GANGLION & NUCLEUS

5. TRIGEMINAL Ganglion

6. THE TRIGEMINAL GANGLION
• SEMILUNAR OR GASSERIAN GANGLION.
• LOCATION:
lies in a bony fossa at apex of the petrous temporal bone on floor of
middle cranial fossa.
COVERINGS: covered by dural pouch = MECKLES CAVE
ARTERIAL SUPPLY: Ganglionic branches of Internal Carotid Artery,
middle meningeal artery and accessory meningeal artery.

7. TRIGEMINAL NUCLEUS
• A cranial nerve nucleus is a collection of neurons (gray matter) in the
brain stem that is associated with one or more cranial nerves
• Sensory Nuclei
• Motor Nuclei

8. SENSORY NUCLEI
• 1.Mesencephalic nucleus
• 2.Principal sensory nucleus
• 3.Spinal nucleus

9. MOTOR NUCLEI
• Innervates muscles of mastication and tensor tympani and tensor
palatini
• Located in pons medial to principle sensory nucleus.

10. DIVISIONS OF TRIGEMINAL NERVE
• 1. Ophthalmic nerve
• 2. Maxillary nerve
• 3. Mandibular nerve

12. OPTHALMIC NERVE
• Smallest division
• Sensory only
Course :
emerges from trigeminal ganglion
lateral wall cavernous sinus
3 branches in ant part of cavernous sinus
lacrimal, naso cilliary, frontal
superior orbital fissure Orbit

13. Divisions
• Lacrimal
• Frontal
• Nasocilliary

14. Common Tendinous Ring

16. Lacrimal Nerve
• Smallest
• Passes into orbit through lateral compartment of the Superior orbital
fissure outside the tendinous ring.
• Sensory to lateral conjunctiva, Upper Lid, lacrimal gland

17. 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
• It is visualized through the periorbita after removal of the orbital roof
• Branches - The frontal nerve courses outside and superolateral to the
annular tendon and divides into
• Supratrochlear Nerve
• Supraorbital Nerve

18. SUPRATROCHLEAR NERVE
• Smaller nerve
• Medial branch
• The supratrochlear nerve runs anteriorly above the trochlea of the
superior oblique muscle with the supratochlear artery
• The supratrochlear nerve is located medial to the supraorbital nerve
at the supraorbital rim
• supplies: median conjunctiva, Upper Lid and lower part of forehead

19. SUPRAORBITAL NERVE
• Larger nerve
• Lateral branch
• Passes through supraorbital Foramen
• The nerve innervates the upper eyelid, the mucous membrane of
the frontal sinus of the frontal bone, It ascends on the forehead,
dividing into a smaller medial and a lateral branch, which supply the
skin of the scalp nearly as far back as the lambdoid suture

21. NASOCILLIARY NERVE
• Purely Sensory
• Passes through middle part of superior orbital fissure within the
tendenious ring .
• Runs along medial wall of orbit between Superior Oblique and Medial
Rectus
•

23. Branches
• 1. Short Clliary Nerves: sensory root of Cilliary Ganglion
• 2. Long Cilliary Nerves supply to Iris and Cornea.
• 3. Post Ethmoidal Nerve: passes through posterior ethmoidal foramen
to supply the Ethmoid and Sphenoid Sir sinuses.
• 4. Infratrochlear Nerve: Supplies to skin of lacrimal sac ,conjectiva and
upper half of the nose
• 5.Anterior Ethmoidal Nerve: Skin of Lower half of the nose

24. Superior orbital fissure.
• The superior orbital fissure (SOF) is the narrow cleft through which the orbit
communicates with the middle cranial fossa.
• The SOF is situated between the greater and lesser wings and body of the
sphenoid bone. It has a somewhat triangular shape
• L: lacrimal nerve (branch of CN V1)
• F: frontal nerve (branch of CN V1)
• S: superior ophthalmic vein (tributary to cavernous sinus)
• T: trochlear nerve (CN IV)
• SO: superior division of the oculomotor nerve (CN III)
• N: nasociliary nerve (branch of CN V1)
• IO: inferior division of the oculomotor nerve (CN III)
• A: abducens nerve (CN VI)

25. The Superior Orbital Fissure Syndrome
• The superior orbital fissure syndrome (SOFS) is characterized by
ophthalmoplegia, ptosis and proptosis of the eye, fixation and dilation
of the pupil and anaesthesia of the upper eyelid and forehead.
• fractures of the orbit
• neoplasm of the retrobulbar space
• haematoma in the orbital muscle cone

26. Treatment
• Conservative treatment through observation alone has been suggested due
to the operative difficulty and risk of further injury from surgical
exploration.
•
• Shama SA, Gheida U. Superior orbital fissure syndrome and its mimics:
What the radiologist should know? The Egyptian Journal of Radiology and
Nuclear Medicine. 2012;43(4):589-94.

27. MAXILLARY NERVE
• Second division of trigeminal nerve
• Pure sensory
• Supplies derivatives of maxillary process and frontonasal process

31. Course
• Trigeminal ganglion-> Middle cranial fossa
• Lateral wall of cavernous sinus
• Foramen rotundum
• Pterigopalatine fossa
• Through inferior orbital fissure into orbit as INFRA ORBITAL NERVE
• Through infraorbital foramen on face

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

33. • IN PTERIGOPALATINE FOSSA:
• 1. Ganglionic branches arises as 2trunks.
• Trunks join to form single root within pterygopalatine ganglion. Gives
Oribtal branches, Palatine branches, Pharyngeal branches , Nasal
branches Gives postganglionic secretomotor fibers to lacrimal gland
via zygomaticotemporal and lacrimal.

34. • 2.Orbital branch: Supplies periosteum of orbit
• 3.Nasal branch: Supplies to mucosa of superior and inferior conchae,
posterior ethimoidal sinus and posterior portion of nasal septum. It
also includes Nasopalatine branch.
• 4.Palatine branch: Arise as greater palatine (anterior) and lesser
palatine (middle and posterior)

35. POSTERIOR SUPERIOR ALVEOLAR NERVE
• It arises from the main trunk of maxillary nerve in the petrygopalatine
fossa just before the nerve enters the inferior orbital canal - Usually
arises as 2 trunks.

37. • Middle superior alveolar nerve: runs along lateral wall of maxilla
Participates in superior dental plexus Supplies premolars.
• Anterior superior alveolar nerve: Runs in canal in anterior wall of
maxilla
Dental branches - supply canines
Nasal branches - opening of max sinus

38. Zygomatic nerve :
• Zygomaticofacial nerve -Appears on face through foramen in the
zygomatic bone -Supplies skin on prominence of cheek
• Zygomaticotemporal nerve --Appears in infratemporal region thru
foramen in zygomatic bone -Supplies skin of temporal region after
peircing temporal fascia 2 cm above zygoma -Gives communicating
branch to lacrimal N suppling parasymp. Secretomotor fibres to
lacrimal gland.

39. FACIAL BRANCHES:
• 1.Palpebral Branch-pierces Orbicularis Occuli and supplies skin of
lower lid.
• 2.Nasal branches-supplies skin of lateral wall nose
• 3. Superior labial nerve- supplies upper lip, cheek and cheek.

40. Maxillary Nerve Approach
• HighTuberosity Approach
• Greater palatine cannal Approach

41. MANDIBULAR NERVE
• Motor root- from motor nucleus in pons
• sensory root- gasserian ganglion
• exit through foramen ovale in greater wing of sphenoid from trunk
which remain 2-3 mm undivided in infratemporal fossa travels
between lat. Pterygoid and Otic ganglion laterally and tensor palatine
medially anteriorly to Middle Meningeal Artery
• Thus divided into small anterior division and large posterior Division

43. Branches
Trunk (undivided)
1.Nervous Spinosus 2.Nerve to medial Pterygoid
Anterior Division
• Massetric Nerve.
• Deep temporal Nerve.
• Nerve to lateral Pterygoid
• Buccal Nerve.
Posterior Division – 1.Auriculo Temporal Nerve 2. Inferior. Alveolar Nerve 3.
Lingual Nerve

44. Branches from trunk
• Before dividing into anterior and posterior division it gives 2 branches
during its 2-3mm path
1. Meningeal branch of Mandibular nerve
• It re-enters cranial cavity through foramen spinosum 2.Nerve to
medial Pterygoid - Supplies medial pterygoid
• The medial pterygoid nerve arises from the medial aspect of the main
trunk below the foramen ovale close to the otic ganglion and
descends to supply the medial pterygoid muscle It contains sensory,
motor, and proprioceptive fiber of the medial pterygoid muscle.

46. Branches from the anterior division
• 1.Nerve to lateral pterygoid: It enters the deep surface of the muscle.
• 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
• 3.Buccal nerve- The buccal nerve passes anterolaterally between the two heads
of the lateral pterygoid, below the inferior portion of the temporal muscle,
• It emerges from the undersurface of the ramus of the mandible and the anterior
border of the masseter muscle
• The buccal nerve was found to lie 3 cm lateral to the angle of the mouth
• 4.Deep temporal nerve- There are anterior and posterior deep temporal nerves.
Passes between skull, and enters deep surface of the temporalis

48. Branches Of Posterior Division

49. Auriculotemporal 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

50. Branches
• The anterior auricular branch provides somatosensory innervation to the skin of
the ear, including the tragus and part of the helix.
• The articular branch provides somatosensory innervation to the posterior
temporal mandibular joint
• The parotid branch receives its preganglionic fibers from the lesser petrosal
nerve. This branch provides secretomotor innervation via parasympathetic fibers
to the parotid gland.
• The superficial temporal branches run posterior to the superficial temporal
artery. These branches provide somatosensory innervation to the skin over the
temple. This branch also anastomoses with the facial nerve and
zygomaticotemporal nerve.
• The branch to the external auditory meatus provides somatosensory innervation
to the skin of the meatus as well as the tympanic membrane.

51. Freys syndrome
Frey syndrome is a postoperative phenomenon following salivary gland surgery and less commonly neck
dissection, facelift procedures, and trauma that is characterized by gustatory sweating and flushing
It described sweating and flushing in the preauricular area in response to mastication or a salivary
stimulus.

52. Symptoms
Flushing
Sweating
Burning
Neuralgia
itching.

53. Examination
• blue/brown in the presence of iodine and sweat

54. THE PREVENTION
• Increased Skin Flap Thickness
• Muscle Flaps
• Botox
• Frey L. Le syndrome du nerf auriculo-temporal. Revue Neurologique
1923;2: 92–104. 2. Freedberg A, Shaw R, McManus J. The auriculotemporal
syndrome. A clinical and pharmacologic study. J Clin Invest 1948;27(5):669–
76.

55. Inferior alveolar nerve
• Is mixed nerve
• Sensory branches are the incisive nerve, the mental nerve, and the
nerve to the lower premolars and molars. The motor branch is the
nerve to the mylohyoid
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 through mandibular foramen to run in a bony canal
below the teeth

58. Branches
• 1.Mylohyoid: Arises just before the nerve enters mandibular
foramen.It pierces the sphenomandibular ligament along with
mylohyoid muscle and runs in the mylohyoid goove. Supplies to
mylohyoid muscle.
• 2.Branches to lower teeth and gums.
• 3.Mental nerve : It exits canal and divides into three branches
innervating skin of chin and skin and mucous membrane of the lower
lip.
• 4.Incisive nerve : It remains within the canal and form plexus that
innervates pulpal tissue of first premolar canine and incisors through
dental branches.

59. Lingual nerve
• The lingual nerve is the main branch of the posterior division of V3
that provides sensation to the anterior two-thirds of the tongue and
gingiva variably along the lingual side of the mandibular teeth.

61. Lingual Nerve Injury
Lingual nerve injury causing numbness, dysesthesia, paresthesia, and dysgeusia may complicate invasive dental
and surgical therapies
Trigeminal nerve injuries have been reported following tooth removal, tumor removal, osteotomy, distal wedge
techniques, implant placement, and general dental therapies such as nerve block, crown preparation, and
endodontic procedures

62. Examination of trigeminal nerve
1- Sensation Function
2- Motor Function
3- Corneal reflex

63. Sensation function
• use sterile sharp item on forehead, cheek, and jaw If any abnormality
present we test the thermal sensation and light touch

64. Motor Function
• Palpate Temporal & Masseter muscle as the patient clenches the
teeth.

65. Corneal Reflex
• a clean piece of cotton wool and ask the patient to look away gently
touch the cornea with the cotton wool and the patient will blink

66. Trigeminal Neuralgia

67. INTRODUCTION
• Trigeminal neuralgia or tic douloureux is a neuropathic disorder of
trigeminal nerve that causes episodes of intense pain in eyes, lips,
scalp, forehead and jaws.
• It has been labeled as suicide disease due to insignificant number of
people taking their own life because they are unable to have their
pain controlled by medication or surgery.

68. • It is a truly agonizing condition, in which the patient may clunch the
hand over the face & experience severe, lancinating pain associated
with spasmodic contractions of the facial muscles during attacks

69. Pathophysiology
Atherosclerotic blood vessel pressing on the root of trigeminal
nerve
Focal demyelination
Hyperexcitability of nerve fibres.
Episode of intense pain

70. GENERAL CHARACTERISTICS
• INCIDENCE : It is a rare affliction, seen in about 4 in 1,00,000 persons.
• AGE OF OCCURRENCE: 5th or 6th decade
• SEX PREDILECTIONS: with female predispositions 58%
• AFFLICTION FOR SIDES : Predilections for right side is noted 60%
• DIVISION OF TRIGEMINAL NERVE INVOLVEMENT : V3 is more commonly involved than
V2 division. Very rarely V1 ophthalmic division is involved in about 5% of cases (only
sensory division is affected)

71. SYMPTOMS
• Sudden burning or shock like facial pain
• episodes can be 5 seconds to 2 minutes
• multiple occurence per day are possible
• no pain between attacks
• talking, eating, brushing teeth, or even cool air on the face
• Flurries of episodes can occur from weeks to months then stop abruptly for a month or yar at
a time
• there is no loss of taste ir hearing in someone suffering from tic doulerex

72. TRIGGER FACTORS
• Hair brushing and cleaning of
teeth
• tilting head and shaving
• Stress and tiredness
• Cold and hot weather
• Chewing and swallowing
• Touching and washing face
• Light breeze and wind on face

73. DIAGNOSIS
1. The pain paroxysmal
2. The pain may be provoked by light touch to the face(trigger zones)
3. The pain is confident to trigeminal distribution
4. The pain is unilateral
5. The clinical sensory examination is normal.

74. PHARMACOLOGICAL MANAGEMENT
• FIRST LINE OF APPROACH
Carbamazepine 100, 200mg..
• SECOND LINE OF APPROACH
Phenytoin 100mg
Baclofen 5-80 mg day
Lamotrigine 25 mgday

75. SURGERY
• The decision to opt for surgery is based on response to and side
effects from medical treatment, the patient’s age and profession, and
the surgical facilities and expertise available.
• Surgery may be aimed peripherally at the affected nerve or centrally
at the trigeminal ganglion.

76. SURGICAL MANAGEMENT
• PERIPHERAL INJECTION: It has been known that injection of
destructive substance into peripheral branches of the trigeminal
nerve, produces anesthesia in the trigger zones or in areas of
distribution of spontaneous pain.
(A) LONG ACTING ANAESTHETIC AGENTS: Without adrenaline such as
bupivacaine with or without corticosteroids may be injected at the
most proximal possible nerve site.

77. • (B) ALCOHOL INJECTION: 0.5 – 2 ml of 95 % absolute alcohol can be
used to block the peripheral branches of the trigeminal nerve. Aim is
to destroy the nerve fibers. It produces total numbness in the region
of distribution of the nerve that was anaesthetized.
Complication:
• Necrosis of the adjacent tissue
• Fibrosis
• Alcohol induced neuritis

78. Gamma Knife Radio Surgery

79. Peripheral Neurectomy
• Oldest and most effective method.
• Mostly performed on the infraorbital nerve, inferior alveolar nerve,
mental nerve and rarely lingual nerve.

80. LINGUAL NEURECTOMY:
• An incision is made in the anterior border of the ramus slightly
towards the lingual side.
• The lingual aspect is exposed & the lingual nerve identified in the
third molar region just below the periosteum.
• The nerve can be either avulsed or ligated, cut and the ends may be
cauterized.

81. Cryotherapy
• Direct application of cryoprobe (temperature -60°) intraorally to the
affected nerve producing wallerian degeneration of the affected
nerve.
• In this, the nerve is not sectioned but destroyed.

82. Conclusion
• Trigeminal Neuralgia has been an enigma to physicians for a long
course of time. There have been various advances in the
understanding of the pathogenesis of the disease per se and the
treatment modalities.
• However various treatment modalities suggests dissatisfaction with
any one single procedure.
• Hence the golden rule still remains optimum scrutinisation and
authentic diagnosis which is a key to the success of any treatment

83. References
• Cunningham’s Manual of practical anatomy by G.J. Romanes
• Last’s Anatomy by Chummy.S
• IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-
0861.Volume 17, Issue 8 Ver. 13 (August. 2018)
• Anatomic Study of Extracranial Needle Trajectory Using Hartel Technique for Percutaneous
Treatment of Trigeminal Neuralgia Joe Iwanaga1,2 , Filippo Badaloni3 , Tyler Laws1 , Rod J.
Oskouian1 , R. Shane Tubbs1,
• Merril RG. Oral neurosurgical procedures for nerve injuries. In: Walker RV, ed. Transactions 3rd
International Conference in Oral Surgery held in New York 7–12 October 1968. London: E & S
Livingstone, 1970
• Svane TJ, Wolford LM, Milam SB, Bass RK. Fasicular characteristics of the human inferior dental
nerve. J Oral Maxillofac Surg 1986;44:431–434.
• Bruce RA, Frederickson GC, Small GS. Age of patients and morbidity associated with mandibular
third molar surgery J Am Dent Assoc. 1980 Aug;101(2):240-5. [Medline: 6931159]

84. Thank You !