The trigeminal nerve is the largest of the cranial nerves. It has both sensory and motor functions, transmitting sensations from the face and motor commands to the muscles of mastication. The trigeminal nerve consists of three main divisions - the ophthalmic, maxillary, and mandibular nerves - which each have distinct sensory distributions and ganglia. Injuries or disorders of the trigeminal nerve can result in conditions like trigeminal neuralgia, which causes severe facial pain.

1. ODMORNIN

4.  The trigeminal nerve is the largest cranial nerve
 The great sensory nerve of the head and face
 Motor nerve of the muscles of mastication
 Term by- Winslow
 First described by- Fallopius and Meckel in 1748
 It emerges from the side of the pons
-small motor root
-large sensory root

5. The trigeminal nerve has three sensory and one motor nuclei.
The sensory nuclei are the principal, mesencephalic, and spinal
sensory

8.  Arise from the motor nucleus within pons and
medulla.
 At the semilunar ganglion motor root passes in a
lateral and inferior direction
 Leaves the middle cranial fossa through the foramen
ovale
 Just after leaving the skull it unites with sensory root
to form a single nerve trunk.

9.  Arise from the semilunar ganglion which lies in a
cavity of the dura mater near the apex of the petrous
temporal bone.
 They pass backward below the superior petrosal sinus
and tentorium cerebelli, and, entering the pons, divide
into upper and lower roots.

10.  Occupies a cavity called cavum Meckelii
 Crescent-shaped, with its convexity directed forward:
medially, in relation with the internal carotid artery
and the posterior part of the cavernous sinus.
 The greater superficial petrosal nerve lies underneath
the ganglion.
 The ophthalmic, maxillary, and mandibular nerves
proceed from its convex border.

12. Sensory areas of the head, showing the general
distribution of the three divisions of the fifth nerve

13. Ganglia associated with Trigeminal nerve
 ciliary ganglion - ophthalmic nerve
 sphenopalatine ganglion - maxillary nerve
 Otic ganglia - mandibular nerve
 submaxillary ganglia - mandibular nerve

15.  Smallest of the three divisions of the trigeminal,
 Arises from the upper part of the semilunar ganglion which
passes forward along the lateral wall of the cavernous sinus,
below the oculomotor and trochlear nerves;
 Just before entering the orbit, through the superior orbital
fissure, it divides into three branches, lacrimal, frontal, and
nasociliary

16.  the smallest of the three branches of the ophthalmic
 It enters the lacrimal gland and gives off several filaments,
which supply the gland and the conjunctiva.

17.  The largest branch of the ophthalmic
 It enters the orbit through the superior orbital fissure,
and runs forward between the Levator palpebrae
superioris and the periosteum
 Midway between the apex and base of the orbit it
divides into two branches, supratrochlear and
supraorbital.

18. It supplies the skin of the lower part of the forehead
close to the middle line and the conjunctiva and skin of
the upper eyelid.
The supraorbital nerve (n. supraorbitalis):
It exit the orbit through the supraorbital notch
supply the upper eyelid, conjuctiva, and forehead.

20.  It supplies internal nasal branches to the mucous membrane of
the front part of the septum and lateral wall of the nasal cavity.
 Finally, it emerges as the external nasal branch and supplies
the skin of the ala and apex of the nose.
 Branches:
◦ the long root of the ciliary ganglion
◦ the long ciliary
◦ the ethmoidal nerves

21. Enters the postero-superior angle of the ciliary ganglion
It is sometimes joined by a filament from the cavernous plexus
of the sympathetic chain.
The long ciliary nerves (nn. ciliares longi):
The long ciliary nerves are supposed to contain sympathetic
fibers from the superior cervical ganglion to the Dilator pupillæ
muscle.

22.  Is given off from the nasociliary just before it enters the
anterior ethmoidal foramen.
 Passes to the medial angle of the eye, and supplies the skin of
the eyelids and side of the nose, the conjunctiva, lacrimal sac.
The ethmoidal branches (nn. ethmoidales):
 Supply the ethmoidal sinus
 The posterior branch leaves the orbital cavity through the
posterior ethmoidal foramen and gives some filaments to the
sphenoidal sinus.

24.  second division of the trigeminal, is a sensory nerve
 It is intermediate, both in position and size, between
the ophthalmic and mandibular
 It begins at the middle of the semilunar ganglion as a
flattened plexiform band
 It leaves the skull through the foramen rotundum,
where it becomes more cylindrical in form

25.  In the Cranium:
◦ Middle meningeal.
 In the Pterygopalatine Fossa:
◦ Zygomatic
◦ Sphenopalatine
◦ Posterior superior alveolar.
 In the Infraorbital Canal:
◦ Anterior superior alveolar
◦ Middle superior alveolar.
 On the Face:
◦ Inferior palpebral
◦ External nasal
◦ Superior labial

26.  Given off from the maxillary nerve directly after its
origin from the semilunar ganglion
 It accompanies the middle meningeal artery
 Supplies the dura mater

27.  Arises in the pterygopalatine fossa
 Enters the orbit by the inferior orbital fissure
 Divides into two branches, zygomaticotemporal and
zygomaticofacial.

28.  Originates from maxillary nerve in pterygopalatine
fossa ,through the pterygopalatine fissure enter the
infratemporal fossa and goes to the posterior surface
of maxilla through small alveolar foramen.
 Supply mucous membrane of maxillary sinus , molar
tooth, except mb root of 1st
molar, and adjacent buccal
gingiva.

29.  Orbital branch – supply orbital wall, sphenoidal and
ethmoidal sinus
 Greater palatine – supply mucosa and gland of hard palate
and adjacent gingiva almost as forward as
incisor teeth
 Lesser palatine –supply soft palate and tonsils
 Nasal branch –supply mucous membrane of superior and
middle concha, lining of post. ethmoidal
sinus and nasal septum…. Its largest br. is
nasopalatine that supplies mucosa,
gingiva, gland adjacent to incisor teeth
 Pharyngeal branch –supply mucosa and gland of
nasopharynx

30.  Given off from the nerve in the posterior part of the
infraorbital canal
 Runs downward and forward in a canal in the lateral
wall of the maxillary sinus
 supply the two premolar teeth and mesiobuccal root
of 1st
molar and adjacent buccal gingiva.
 Absent in 30% individuals

31.  Given off from the nerve just before its exit from the
infraorbital foramen
 It descends in a canal in the anterior wall of the
maxillary sinus
 Divides into branches which supply the incisor and
canine teeth, adjacent labial gingiva

32.  Supply the skin and conjunctiva of the lower eyelid,
joining at the lateral angle of the orbit with the facial
and zygomaticofacial nerves

33.  Supply the skin of the side of the nose and the septum
alaque nasi
 Join with the terminal twigs of the nasociliary nerve

34.  The largest and most numerous
 Distributed to the skin of the upper lip, the mucous
membrane of the mouth, and labial glands.
 They are joined immediately beneath the orbit, by
filaments from the facial nerve, and form the
infraorbital plexus.

36. The braches of the Mandibular nerve:-
I. Branches of the undivided nerve.
i. Meningeal branch/nervus spinosus.
ii. Nerve to the medial pterygoid
II. Branches of the divided nerve:
(A)Anterior division: (B) Posterior division:
1.Buccal nerve 1. Auriculotemporal nerve
2.Massetric nerve 2.Lingual nerve
3.Deep temporal nerve 3.Inferior alveolar nerve
4.Nerve to the lateral pterygoid.

37.  Enters the skull through the foramen spinosum with the
middle meningeal artery.
 two branches:
◦ anterior branch which accompany the main divisions of the
artery and supply the dura mater
◦ the posterior branch also supplies the mucous lining of the
mastoid cells;
The Internal Pterygoid Nerve
A slender branch, which enters the deep surface of the
muscle

38. It crosses the mandibular notch with the masseteric artery,
to the deep surface of the Masseter, in which it ramifies
nearly as far as its anterior border
The Deep Temporal Nerves
Two in number, anterior and posterior.
Laterally above the lateral pterygoid musle, curve around
infratemporal crest and ascend to temporal fossa and
supplies temporalis muscle

39.  The buccinator nerve supplies the skin over the
Buccinator, and the mucous membrane lining its inner
surface and adjacent oral mucosa and buccal gingiva of
lower molar.

40.  Generally arises by two roots, between which the
middle meningeal artery ascends.
 It runs backward beneath the Pterygoideus
externus to the medial side of the neck of the
mandible.
 It supplies parotid gland, skin over the meatus,
and tympanic membrane, post. Portion of TMJ
and skin over temporal region

41.  This is the smallest of the posterior division.
 It passes medial to the lateral pterygoid & it lies between the
ramus of the mandible & the muscle in the pterygomandibular
space.
 It gives off sensory fibers to the tonsil & the mucous
membrane of the posterior part of the oral cavity.
 In the pterygomandibular space, it lies parallel to the inferior
alveolar nerve, but medial & anterior to it.

42.  It then passes deep to reach the side of the tongue.
Here it lies in the lateral lingual sulcus against the
deep surface of the mandible on the medial side of
the roots of the third molar tooth where it is covered
only by mucous membrane of the gum.
 From here it passes on to the side of the tongue where
it crosses the styloglossus & runs on the lateral
surface of the hyoglossus & deep to the mylohyoid in
close relation to the deep part of the submandibular
gland &its duct.

43.  Its branches of communication are with the facial
(through the chorda tympani), the inferior alveolar
and hypoglossal nerves, and the submaxillary
ganglion.

44.  Its branches of distribution
◦ Sublingual gland
◦ The lingual - mucous membrane
◦ The lingual portion of the gums
◦ The terminal filaments communicate, at the tip of the
tongue, with the hypoglossal nerve

46.  The largest branch of the mandibular nerve.
 It descends with the inferior alveolar artery,
 It then passes forward in the mandibular canal,
beneath the teeth, as far as the mental foramen.
 Branches to the mandibular teeth as apical fibres &
enters the apical foramen of the teeth to supply
mainly the pulp as well as the periodontium.
 The branches of the inferior alveolar nerve are the
mylohyoid, dental, incisive, and mental

47. Branches of the nerve :-
1.Mental nerve: it supplies to the skin of the chin & the
mucous membrane as well as the skin of the lower lip.
2.Incisive branch: continues anteriorly from the mental
nerve in the body of the mandible to form the incisive
plexus & supplies the canine & incisors.
3.Mylohyoid nerve: it is given of before the nerve enters
the canal & contains both sensory & motor fibres and
supplying the mylohyoid muscle as well as the anterior
belly of the digastric.

48. Ophthalmic NerveOphthalmic Nerve Maxillary NerveMaxillary Nerve Mandibular NerveMandibular Nerve
nasal cavitynasal cavity
orbital contentsorbital contents
frontal & ethmoidfrontal & ethmoid
sinussinus
upper eyelidupper eyelid
dorsum of nosedorsum of nose
ant.part of scalpant.part of scalp
dura in ant &dura in ant &
middle cranial fossamiddle cranial fossa
NasopharynxNasopharynx
PalatePalate
nasal cavitynasal cavity
upper teethupper teeth
maxillary sinusmaxillary sinus
lower eyelidlower eyelid
CheekCheek
upper lipupper lip
Skin of lower faceSkin of lower face
CheekCheek
Lower lipLower lip
EarEar
Temporal fossaTemporal fossa
Ant 2/3Ant 2/3rdrd
of tongueof tongue
Lower teethLower teeth
Mastoid air cellsMastoid air cells
MandibleMandible

49. APPLIED
ANATOMY

50. Maxillofacial procedures that run the risk of injury
to one of the peripheral branch of trigeminal nerve:
 Inferior alveolar nerve: mandibular
impacted 3rd
molar,endosteal implant placement,visor
osteotomy, mandibular osteotomies,cysts and tumor
removal,genioplasties and ostomyelitis.

51.  Lingual nerve:
3rd
molar removal, excision of sublingual gland,
instrumentation of floor of mouth ,sulcoplasties of
lingual vestibule, tumor removal and mandibular
ramus osteotomies
 Infraorbital nerve:
lefort-II & III level ostotomies,caldwell-luc
procedures,orbital osteotomies, fractures of mid face
and orbits

52.  Neuralgia
◦ Unexplained peripheral nerve pain
neuralgia (TN)
 Fothergill’s disease
 Tic douloureux (painful jerking)
 Mean age: 30--50 y/o
 Female predominance (male : female = 2:3)

53.  paroxysms of severe, lancinating, electric
shock-like bouts of pain restricted to the
distribution of the trigeminal nerve
◦ Unilaterally (right side)
◦ The mandibular (V3) and/or maxillary (V2)
branch or, rarely, the ophthalmic (V1) branch
 Spontaneously attack or triggered by trigger
zone & movement of the face
 Seconds to minutes

55.  Uncertain
◦ Traumatic compression of the trigeminal nerve by neoplastic
(cerebellopontine angle tumor) or vascular anomalies
◦ Infectious agents
 Human herpes simplex virus (HSV)
◦ Demyelinating conditions
 Multiple sclerosis (MS)

56. Classic TNClassic TN
Atypical or mixed TNAtypical or mixed TN
A persistent and dull ache between paroxysms or mild sensory loss

57.  Medical treatment
◦ Carbamazepine (Tegretol) – first line
◦ Oxcarbazepine
◦ Gabapentin (Neurontin)
◦ Lamotrigine
◦ Baclofen
◦ Phenytoin
◦ Clonazepam
◦ Valproate
◦ Mexiletine
◦ Topiramate
Second line
Others

58.  Surgical treatment
◦ Gasserian ganglion-level procedures
 Microvascular decompression (MVD)
 Ablative treatments
 Radiofrequency thermocoagulation (RFT)
 Glycerol rhizolysis (GR)
 Balloon compression (BC)
◦ Peripheral procedures
 Peripheral neurectomy
 Cryotherapy (cryonanlgesia)
 Alcohol block
Neuro-
destructive
procedure
Surgical
decompress

59.  Sudden onset of parasympathetic dysarythmia ,
sympathetic hypotension, apnea or gastric
hypermotility during stimulation of the sensory
branches of the trigeminal nerve.
 TCR may occurs during defferent cranio-facial
surgeries.

60.  Trigeminal sensory nerve endings send neuronal
signals via gasserian ganglion to sensory nucleus
forming the afferent pathway.
 Which continues along the short internuclial nerve
fibers in the reticular formation to connect with the
efferent pathway in the motor nucleus of vagus
nerve.

61.  Lesion in middle cranial fossa especially in the region
between trigeminal ganglion and ICA.
 Usual etiologies: tumor, aneurysm, trauma and
infection.
 Characterized by occulo-sympathetic paresis and
trigeminal involvement.
 Other cranial N involvement 4 and 6 also present

62.  Lesions located at the apex of the temporal bone.
 Trauma, osteitis, and otitis media.
 Involve ophthalmic division of trigeminal and nearby
abducent N.
 Pain and sensory disturbance in the distribution of
trigeminal N, lateral rectus palsy and occulo-
sympathetic paresis

63.  Trauma, Tumor, carotid aneurysm, and carotid
cavernous fistula and infection.
 Ophthalmic, maxillary and abducent and trochlear N
involvement.
 Total ophthalmoplegia and occulomotor palsy if lesion
proceeds from the sella.
 Occulo-sympathetic paresis rarely.

64.  Involves 3,4,6 and ophthalmic division of trigeminal N.
 Complete ophthalmoplegia, pain and sensory
disturbance in the distribution of ophthalmic division.
 Occulo-sympathetic paresis.

65. Mental nerve nueralgia.
 Due to resorption of the lower alveolar ridge, the
borders of the denture flange may compress on the
mental nerve, causing pain. Radiologically, the
foramen can be seen at the level of the surface of the
ridge. Shifting the foramen down is the treatment of
choice.
 Similar pain is felt due to narrowing of the
foramen. Decompession of the nerve by carefully
enlargening the foramen is the treatment of choice.

66. Causalgia:
 It is a term applied to severe pain which arises after injury
to or sectioning of a peripheral sensory nerve.
Clinical Features:
It usually follows extraction of a multirooted tooth particularly
when extraction is difficult or traumatic. The pain arises within
few days to several weeks after the extraction and has a typical
burning quality. The pain develops at the site of the injury and
is evoked by application of heat or cold..
Treatment:
Injection of procaine, alcohol
Surgical curettage of bone
Resection of nerves

67. Crocodile Tears:
 In this patient exhibits profuse lacrimation during eating
especially hot or spicy food.
It generally follows facial paralysis, either of Bells palsy type
or a result of herpes zoster, head injury or intra cranial operative
trauma.
 Whenever an autonomic nerve degenerates from injury or
disease any closely adjacent normal autonomic fibers will give
out sprouts which can connect up with appropriate cholinergic
or adrenergic endings thus a salivary lacrimal reflex arc is
established resulting in crocodile tears.
Treatment:
 Intracranial division of Auriculotemporal nerve.

68. Auriculo Temporal Syndrome (Frey's Syndrome
Gustatory Sweating)
It is an unusual phenomenon which arises as a result of
damage to the auriculo- temporal nerve and subsequent
reinnervation of the sweat glands by parasympathetic
salivary fibers.

69. Etiology:
 The syndrome follows some surgery such as
removal of a parotid tumor or the ramus of the mandible,
TMJ or a parotitis.
Trans-axonal excitation rather than actual anatomic
misdirection of fibers

70. Clinical Features:
 The patient typically exhibits flushing and sweating
of the involved side of the face chiefly in the temporal
area, during eating especially spicy or sour ones.
Profuse sweating may be provoked by the
administration of pilocarpine or eliminated by the
administration of atropine or procaine block.
Treatment:
 Intracranial division of Auriculotemporal nerve