Trigeminal nerve maxillary nerve and clinical implication

1. MAXILLARY BRANCH OF
TRIGEMINAL NERVE AND
ITS CLINICAL IMPLICATION

2. REFERENCES
• Churchill livingstone. Gray’s anatomy Anatomy of the
human body 39th edition.2008
• Rajendran A & Sundaram S.Shafer’s textbook of oral
pathology 7th edition

3. • The nervous system of man is made up of innumerable
neurons which further constitute the nerve fibers
Nerve :
A bundle of fibers that uses chemical and electrical
signals to transmit sensory and motor information from one
body part of the body to another.
Neurons :
These are specialized cells that constitute the functional
units of the nervous system and has a special property of being
able to conduct impulses rapidly from one part of the body to
another.

4. • The cranial nerves are composed of twelve pairs of nerves that
emanate from the nervous tissue of the brain.
In order to reach their targets they must ultimately exit/enter
the cranium through openings in the skull.
Hence, their name is derived from their association with the
cranium.

5. NERVE IN ORDER
• Cranial Nerve I - Olfactory
Cranial Nerve II - Optic
Cranial Nerve III - Occulomotor
Cranial Nerve IV - Trochlear
Cranial Nerve V - Trigeminal
Cranial Nerve VI - Abducens
Cranial Nerve VII - Facial
Cranial Nerve VIII- Vestibulocochlear
Cranial Nerve IX - Glossopharyngeal
Cranial Nerve X - Vagus
Cranial Nerve XI - Spinal Accessory
Cranial Nerve XII - Hypoglossal

6. CLASSIFICATION OF CRANIAL NERVES
• Sensory cranial nerves: contain only afferent (sensory) fibers
• ⅠOlfactory nerve
• ⅡOptic nerve
• ⅧVestibulocochlear nerve
• Motor cranial nerves: contain only efferent (motor) fibers
• Ⅲ Oculomotor nerve
• ⅣTrochlear nerve
• ⅥAbducent nerve
• Ⅺ Accessory nerv
• Ⅻ Hypoglossal nerve
• Mixed nerves: contain both sensory and motor fibers
• ⅤTrigeminal nerve,
• Ⅶ Facial nerve,
• ⅨGlossopharyngeal nerve
• ⅩVagus nerve

7. EMBRYOLOGY OF THE NERVE
• During the development of embryo, the pharyngeal arches appear in
the fourth and fifth week. It give rise to six pharyngeal arches, of which
the 5th arch disappears.
• Each arch is characterized by its own:
muscular component
 nerve component
 arterial component
 skeletal component
• Trigeminal nerve is derived from 1st pharyngeal arch

8. NUCLEI OF TRIGEMINAL NERVE:-
• It has got 4 nuclei :
1) Mesencephalic nuclei
2) Spinal nuclei sensory
3) Main sensory nuclei
4) Motor nuclei

9. SENSORY NUCLEI :
• 1.Mesencephalic nucleus.
Situated in midbrain.
First order sensory nucleus.
Cell body of pseudounipolar neurons.
Recieves general somatic afferent fibres.
Relay proprioception from :
-muscles of mastication
-facial muscles
-eye

10. 2.MAIN SENSORY NUCLEUS
Situated in upper part of pons lateral to motor nucleus.
Receives general somatic afferent fibers.
Relays impulses of touch and pressure from skin and
mucous membrane of facial region.

11. 3.THE SPINAL NUCLEUS:
• it extends from caudal end of principal sensory nucleus in pons to 2nd
or 3rd spinal segment where it continues with sub. Gelatinosa.
Divided into three parts :-
1. Subnucleus oralis
2. Subnucleus interpolaris
3. Subnucleus caudalis
It receives general somatic afferent fibres
Relays the impulses of pain and temperature of face

12. 4.THE MOTOR NUCLUES :-
• It is situated in upper pons medial to principal
sensory nucleus.
• Contains efferent fibres.
• Innervates muscles of mastication and tensor
tympani and tensor palatini.

13. THE TRIGEMINAL GANGLION :-
Also known as Gasserian
ganglion or semilunar
ganglion, is a sensory
ganglion of the
trigeminal nerve that
occupies a cavity
(Meckel’s cartilage) in
the durameter, covering
the trigeminal
impression near the apex
of the petrous part of the
temporal bone.

14. • It is somewhat crescentic or semilunarin shape, with its
convexity directed anteriomedialy. The three divisions of
the trigeminal nerve emerges from this convexity.
• Trigeminal nerve is the largest cranial nerve.
• It is a mixed nerve.
• Composed of a small motor root and a considerably larger
sensory root.
• The sensory root contains 170000 fibres and the motor root
contains 7700 fibres.

15. THE TRIGEMINAL GANGLION

16. Trigeminal nerve
Ophthalmic
(sensory)
Maxillary
(sensory)
Mandibular
(mixed)

17. THE MAXILLARY NERVE:
It is intermediate division of trigeminal nerve.
Wholly sensory.
ORIGIN:
It leaves the trigeminal ganglion between the ophthalmic and mandibular
divisions as a flat plexiform band
Passes slightly medial to lateral wall of cavernous sinus.
Leaves the cranium through foraman rotandum, which is located in the
greater wing of sphenoid bone.

18. •
Once outside the cranium, it crosses the uppermost part of the
pterygopalatine fossa, between the pterygoid plates of sphenoid bone
and the palatine bone
As it crosses the pterygopalatine fossa it gives of branches
sphenopalatine ganglion zygomaticbranches
posterior superior alveolar nerve

19. •
It then angles laterally in a groove on the posterior surface of the
maxilla, entering the orbit through the inferior orbital fissure
•
Within the orbit it occupies the infraorbital groove and becomes the
infraorbital nerve,which courses anteriorly into the infraorbital canal
•
The maxillary division emerges on the anterior surface of face through
the infraorbital foramen, where it divides into its terminal branches,
supplying the skin of the face, nose, lower eyelid and upper lip

21. Maxillary Nerve
Cranial
Cavity
Meningeal
Pterygopalatine
fossa
Zygomatic
Posterior
Superior
Alveolar
Infraorbital
Canal
Middle
Superior
Alveolar
Anterior
Superior
Alveolar
Face
Palpebral Nasal
Superior
Labial

22. MENINGEAL NERVE:
Also known as nervus meningeus medius.
It lies within the cranium.
It receives a ramus from the internal carotid
sympathetic plexus and accompanies the middle
meningeal artery to supply the duramater.

23. BRANCHES THROUGH
PTERYGOPALATINE FOSSA:
• ZYGOMATIC NERVE:-
•
Starts in the pterygopalatine fossa.
Enters the orbit through the inferior orbital fissure.
Divides into two branches.
Zygomaticcotemporal: supplying sensory innervation to skin
on the side of the forehead.
Zygomaticofacial: supplying the skin on the
prominence of the cheek.

24. • Before leaving the orbit the zygomatic nerve
communicates with the lacrimal nerve of the
ophthamic division which carries secretory
fibres from pterygopalatine ganglion to lacrimal
gland.

25. POSTERIOR SUPERIOR ALVEOLAR
NERVE
• It descends from the main trunk of the maxillary
division in the ptergopalatine fossa.
Through the pterygopalatine fossa,it reaches the
inferior temporal surface of the maxilla.
From here it enters maxilla through the psa canal

26. Travel down the posteriolateral wall of the maxillary sinus.
Provides sensory innervation to the mucous membrane of the
sinus.
Continuing downward it provides sensory innervation to the
alveoli,periodontal ligaments,and pulpal tissues of the maxillary
3rd ,2nd and 1st molar.
Applied anatomy:-During a nerve block there is great risk
of hematoma formation .

27. THE PTERYGOPALATINE NERVE:
This nerve turns straight downward after it
has left the trunk of the second division
The pterygopalatine ganglion is attached to
the medial side of the nerve.

28. • Branches of pterygopalatine nerve includes those that supply four
areas:-
orbit
nose– a) superior posterior nasal
medial
lateral
b) nasopalatine
palate- a) greater (anterior)
b)lesser (middle & posterior)
pharynx
The orbital branches supply the periosteum of the orbit.

29. • The superior posterior nasal branches are given off at the level of the ganglion.
Enter the nasal cavity through the sphenopalatine foramen.
Lateral branches of superior posterior nasal nerve supply upper and middle
conchae.
Medial branches of the nerve pass over the roof of the nasal cavity to the nasal
septum, one of the medial branches is distinguished by its great length and by its
diagonal course downward and forward along the nasal septum,it is called the
nasopalatine nerve.
The nasopalatine nerve gives off branches to the anterior part of the nasal septum
and the floor of the nose

30. • Enters the incisive canal , passes into oral cavity via the incisive
foramen, located in the midline of the palate about 1cm
posterior to the maxillary central incisors.
The right and left nasopalatine nerves emerge together
through this foramen and provide sensation to the palatal
mucosa in the region of premaxilla ( canine to central incisor)

31. GREATER PALATINE NERVE:
Emerges on the hard palate through
the greater palatine foramen (usually
located about 1cm towards the
palatal midline, just distal to the
second molar)
The nerve courses anteriorly
supplying sensory innervation to the
palatal soft tissues and bone as far as
the first premolar, where it
communicates with the terminal
fibres of the nasopalatine nerve.
It provides sensory innervation to
some parts of soft palate

32. THE MIDDLE PALATINE NERVE:
Emerges from the lesser palatine foramen along with the
posterior palatine nerve .
Provides sensory innervation to the mucous membrane of soft
palate
The posterior palatine nerve:
Innervates the tonsillar region.

33. THE PHARYNGEAL BRANCH:
It is a small nerve
Passes through the pharyngeal canal and is distributed to the
mucous membrane of the nasal part of the pharynx posterior
to the auditory tube.

34. BRANCHES IN THE INFRAORBITAL CANAL:
•
The nerve enters the orbit through the inferior orbital fissure, and
is then called the infra orbital nerve passing through the infra
orbital canal.
Within the canal it gives of two branches:
middle superior anterior superior
alveolar branch alveolar branch

35. THE MIDDLE SUPERIOR ALVEOLAR
NERVE (MSA):
• Arises from the infra orbital nerve.
Provides sensory innervation to two maxillary premolars and
perhaps to the mesiobuccal root of the first molar and the
periodontal tissues, buccal soft tissues and bone in the
premolar region.
Traditionally it has being stated that the MSA nerve is absent in
30% to 54% of individuals.
In its absence the usual innervations are provided by either the
PSA or the ASA nerve, most frequently the latter.

37. THE ANTERIOR SUPERIOR ALVEOLAR
NERVE (ASA):
It is a relatively larger branch
Given off from the infraorbital nerve at approximately 6 to
10mm before the latter exit from the infraorbital foramen
It provides pulpal innervation to the:
central and lateral incisors
canine
periodontal tissues
buccal bone
mucous membrane of these teeth.

38. BRANCHES ON THE FACE:
The infraorbital emerges through the infraorbital foramen onto
the face to divide into its terminal branches:
1) the inferior palpebral:- supplying the skin of the lower eyelid
2) the external nasal branch:- providing sensory innervation to
skin of lateral part of the nose
3) the superior labial branch:- supplying the skin and mucous
membrane of the upper lip.

39. APPLIED ANATOMY :-
•
1.Trigeminal neuralgia.
2. Herpes zoster ophthalmicus.
3.Wallenberg Syndrome.

40. TRIGEMINAL NEURALGIA:-
also known as Fothergill’s disease
Tic douloureux (painful jerking)
it is defined sudden, usually, unilateral, severesuas ,
brief, stabbing , lancinating, recurring pain in the
distribution of one or more branches of trigeminal
nerve.
Mean age: 50 y onwards
Female predominance (male : female = 1:2 ~2:3)

41. PATHOGENESIS OF TRIGEMINAL
NEURALGIA
•
It is usualy idiopathic.
The probable etiologic factors are:-
Intra cranial tumors:-Traumatic compression of the trigeminal
nerve by neoplastic or vascular anomalies eg arteriovenous
malformations
Infections : infections involving 5th cranial nerve.
• Intracranial vascular abnormalites

42. GENERAL CHARACTERISTICS
Incidence:- seen in about 4 in 100000 persons
Age of occurrence:- 5th to 6th decade
Sex predilection:-female predisposition
Side involved more frequently:-right side
Division of trigeminal nerve involve; most commonly
mandibular > maxillary >ophthalmic

43. CLINICAL CHARACTERISTICS:-
 Sudden
 Unilateral
 sharp shooting
 lancinating shock like pain elicted by slight touching
 superficial trigger points which radiates across the distribution of one
or more branches of the trigeminal nerve
 pain rarely crosses the midline
 pain is of short duration and last for few seconds to minutes in
extreme cases patient has a motionless face called the frozen or mask
like face
presence of intraoral or extraoral trigger points

44. TRIGGER ZONE

45. • Provocated by obvious stimuli like
Touching face at particular site
Chewing
Speaking
Brushing
Shaving
Washing the face
The characteristic of the disorder being that the attacks do not
occur during sleep.

47. DIAGNOSIS:-
CLINICAL EXAMINATION with HISTORY is
mandatory
Response to treatment with tablet of
carbamazepine is univeral
Injections of local anaesthetic agents into
patients trigger zone gives temporarily relief
from pain.

48. TREATMENT
• Medical treatment
• Surgical treatment:-
• Peripheral injections
• Peripheral neurectomy
• Cryotherapy
• Peripheral radiofrequency
• Neurolysis(thermocoagulation)
• Carbamazapine and phenytoin are the traditional anticonvulsants given
primarilary.
The dosage of the drug used intially should be kept small to minimum especialy
in elderly patients to avoid nausea, vomiting and gastric irritation.

49. THE ALCOHOLIC INJECTIONS:-
•
95% ABSOLUTE alcohol in small quantites 0.5 to 2 ml is given
in peripheral branches of trigeminal nerve.
Side effect:- Repeated injections may cause
Local tissue toxicity
Inflammation
Fibrosis

50. HERPES ZOSTER OPHTHALMICUS:-
• Caused by Varicella zoster
Predilection for nasociliary branch of ophthalmic division of the
trigeminal nerve
CLINICAL FEATURES:-
Cutaneous lesions:-
Rash
Vesicle
Pustule crust permanent scar

51. OCULAR LESIONS:-
Eyelid:- Perorbital pain
Oedema
Hyperasthesia
Conjunctivitis
Corneal scarring

52. TREATMENT:-
• Acyclovir 800mg 5 times /day within 4 days of onset of rash
Analgesics
Antibiotic ointments
Systemic steroids 60mg/day
Corneal grafting

53. THANK YOU