Trigeminal Nerve And Endodontics

TRIGEMINAL
NERVE
DR. NEHAASOLE
MDS FIRST YEAR
DEPT OF CONS & ENDO

CONTENT
1. Introduction
2. Trigeminal Nerve
3. Trigeminal Nuclei
4. Functional Components
5. Course and Distribution
6. Trigeminal Ganglion
7. Divisions of Trigeminal Nerve
8. AppliedAnatomy
9. Conclusion
10. References

INTRODUCTION
Fifth and the Largest cranial nerve.
It is the nerve of first brachial arch.
It has 3 branches: 1. Ophthalmic – sensory
2. Maxillary – sensory
3. Mandibular – mixed
• The trigeminal nerve originates from three sensory nuclei and one motor
nucleus extending from the midbrain to the medulla.

Functional component and
nuclear columns
1=General somatic afferent column.
2=branchial efferent column

1. General somatic afferent column:
• Spinal nucleus of V nerve: It takes pain and
temperature sensations from most of the
face area which relay here.
• Superior sensory nucleus: Fibres carrying
touch and pressure relay in this nucleus.
• Mesencephalic nucleus: extends from
pons till midbrain. It receives
proprioceptive impulses from muscles
of mastication, TMJ & teeth.

2= Branchial efferent column
 Situated at level of upper pons .
 The fibres of motor nucleus supply eight muscles
derived from first branchial arch.

Sensory components of V Nerve
Sensation of pain, temperature, touch and pressure from skin of
face, paranasal air sinuses travel along axons. Their cell bodies lie
in the V ganglion or semilunar ganglion or Gasserian ganglion.

There are two ganglia one innervating each side of face
They are locatedin Meckel’s cave, on anterior surface of petrous
temporal area.
 Sensory root fibersenter the concave portion of each crescent and the
three sensory divisions of trigeminal nerve exit from the convexity.

Motar component
It receives impulses from right and left cerebral hemisperes, red
nucleus and mesencephalic nucleus.
Supply four muscles of mastication and four other muscles that are;
Tensor veli palatini
Tensor tympani
Mylohyoid
Anterior belly of digastric

Ophthalmic Nerve (V1)
FUNCTIONS : The ophthalmic nerve transmits sensory innervation
from;
• Eyeball
• Skin of upper face and anterior scalp
• The lining of upper part of nasal
cavity and air cells
• The meninges of anterior cranial fossa.
• Its branches also convey parasympathetic fibers to the ciliary and iris
muscles,pupillary constriction to the lacrimal gland.

Origin, Course and Branches
It originates from trigeminal ganglion in middle cranial fossa. It
passes anteriorly through lateral wall of cavernous sinus.
 It divides into three branches:
1. Frontal
2. Nasociliary
3. Lacrimal.
All these branches pass
through superior orbital
fissure into the orbit.

FRONTAL BRANCH:
It is the largest branch; supplies frontal sinus and skin of forehead and
scalp.
It divides into two branches:
Supraorbital
Supratrochlear
Frontal

NASOCILIARY BRANCH:
It passes the superior orbital fissure, medially within the common
tendinous ring.
It divides into the following:
a. Short ciliary nerve.
b. Long ciliary nerve.
c. Nerve to ciliary ganglion
d. Infratrochlear
e. Anterior ethmoidal
f. Posterior ethmoidal

LACRIMAL NERVE:
It supplies lacrimal gland and a small area of adjacent skin and
conjunctiva.
It passes through superior orbital fissure.
It receives postganglionic parasympathetic fibers from pterygopalatine
ganglion which enters orbit with zygomatic nerve for distribution to
lacrimal gland.

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

Ocular lesions: Eyelid: Periorbital pain
Oedema
Hyperasthesia
Conjunctivitis
Scleritis
Corneal scarring
Glaucoma

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

Maxillary Nerve (V2)
It is the nerve of maxillary process, that differentiates from first
pharyngeal arch.
It is purely sensory; and is intermediate in size between ophthalmic and
mandibular nerve.

FUNCTIONS:
The maxillary nerve transmits sensory fibers from the skin
of face between the lower eyelid and the nasal cavity and
sinuses, from the maxillary teeth.
At its origin from the pons, it contains only sensory fibers.
 some of its branches receive postganglionic
parasympathetic fibers from pterygopalatine ganglion
which pass to the lacrimal, nasal and palatine glands.

It originates from the middle part of trigeminal ganglion in middle
cranial fossa.
It gives off meningeal branch in middle cranial fossa which is sensory.
The nerve runs forwards through lower part of lateral wall of cavernous
sinus.
directed through the foramen rotundum
As it crosses pterygopalatine fossa, it gives off its main branches.

Maxillary nerve innervates:
1. Skin of: Middle portion of face
Lower eyelid
Side of nose
Upper lip.
2. Mucous membrane of: Nasopharynx
Maxillary sinus
Soft palate
Tonsil
Hard palate.
Maxillary teeth and periodontal tissues.

BRANCHES
Withincranium In pterygopalatinefossa In infraorbitalcanal Onface
MAXILLARY NERVE
Middle meningeal
nerve
• Inferior palpebral
• Lateral nasal
• Superior labial
• MSA
(middle superior
alveolar nerve)
• ASA
(anterior superior
alveolar nerve)
Zygomatic PSA
(posterior
superior
alveolar)
Pterygopalatine
•Zygomatico
temporal
•Zygomatico
facial
•Orbital
•Nasal
•Palatine
•Pharyngeal

Branches Within the Cranium: Middle Meningeal
Nerve
Immediately after separating from trigeminal ganglion, the
maxillary nerve gives off a small branch, middle meningeal
nerve.
It travels with middle meningeal artery.
It provides sensory innervation to the duramater of anterior
half of middle cranial fossa.

Branches in the Pterygopalatine Fossa
i. Pterygopalatine nerves
ii. Zygomatic nerves
iii. Posterosuperior alveolar nerves.

PTERYGOPALATINE NERVES
 They also serve as a communication between pterygopalatine ganglion
and maxillary nerve.
By way of ganglion, the maxillary nerve has the following branches.
1. Orbital branches: Supply periosteum of orbit.
2. Nasal branches: Supply mucous membranes superior and
middle conchae, the lining of posterior ethmoidal sinus and posterior
portion of nasal septum.
These convey postganglionic parasympathetic fibers from pterygopalatine
ganglion to nasal glands.

Nasopalatine nerve (long sphenopalatine nerve) :
 a significant branch.
It enters sphenopalatine foramen
The nasopalatine nerve continues downwards reaching the floor of nasal
cavity and giving off its branches to anterior part of nasal septum and the
floor of nose.

It enters incisive canal through which
it passes into the oral cavity via the
incisive foramen. The right and left
nasopalatine nerves emerge together
through this foramen and provide
sensory innervation to palatal
mucosa in the region of premaxilla.

3. Palatine branches:
a. Greater palatine nerves (anterior palatine nerves)
b. Lesser palatine nerves (middle and posterior palatine nerves).
These branches provide sensory innervation to hard and soft palate.
These branches also convey postganglionic parasympathetic fibers from
pterygopalatine ganglion to palatal glands.
Greater palatine nerves :
It emerges on hard palate through greater palatine foramen
supplying sensory innervation to palatal soft tissues and bone.
Anterior to first premolar it communicates with terminal fibers of
nasopalatine nerve.

Lesser palatine nerve: These are sensory to soft palate. They descend
through lesser palatine foramina in palatine bone and pass backwards to
supply mucous membrane of soft palate.
4. Pharyngeal branch: It provides sensory innervation to
nasopharynx, auditory (Eustachian) tube.

Clinical consideration=
complications include bleeding,infection,nerve
trauma,hypertension.The possibility of needle fracture within
the greater palatine canal. Damage to intracanal vessels and
nerves.
 Failure to gain access to the target area due either to imprecise
technique or greater palatine canal constriction.
Diplopia (Double vision due to anaesthesia of the ocular
muscles via diffusion of anaesthetic solution through the
inferior orbital fissure.)

Clinically management
(a) The patient needs reassurance.
(b) The affected eye requires corneal protection
with an eye pad dressing for the duration of
anaesthesia.
(c) Use of an eye pad will restore normal vision,

ZYGOMATIC NERVES
It provides sensory innervation to skin over zygomatic
region.
These nerves also convey postganglionic parasympathetic
fibers from pterygopalatine ganglion to lacrimal nerve and
glands.
It is a terminal branch. It entering the orbit through inferior
orbital fissure .

The zygomatic nerve enters zygomatic bone and divides
into two branches:
Zygomaticotemporal nerve: supplies skin above
zygomatic arch, anterior part of temporal bone.
Zygomaticofacial nerve: supplies skin over the
prominence of cheek.

POSTEROSUPERIOR ALVEOLAR NERVES
The main trunk of the maxillary nerve in the
pterygopalatine fossa.
Pass downwards through the pterygopalatine fossa and
reach the posterior surface of maxilla.
Provide sensory innervation to:
buccal gingiva in maxillary molar region; and adjacent
facial mucosal surfaces, mucous membrane of sinus and
provides sensory innervation to alveoli, periodontal
ligaments and pulpal tissues of maxillary molars, with
the exception of (25%) mesiobuccal root of first molar.

Clinical consideration
When the local anesthesia was administered for
the posterior superior alveolar nerve block,
forthe RCT of 16, a swelling along with large
extraoral discoloration in the mandibular
lower region.
and a small intraoral hematoma formation
takes place immediately within minutes of
administration of anesthesia.
The patient became very apprehensive about
the unaesthetic appearance of large
discoloration on the side of the face.

Treatment=analgesic, avoid any heat application which might increase
the size of the hematoma due to vasodilatation, application of ice
immediately after developing hematoma helps in minimizing the size by
vasoconstriction.
Any dental treatment in the involved region should be avoided until
symptoms and signs resolve.
To minimize the risk of hematoma formation, use of short needle and
minimum number of needle penetration into tissues should be
considered.
The follow up of the case was done for 4 weeks during which
discoloration was completely disappeared within in 3 weeks.

Branches in the Infraorbital Canal
In the infraorbital canal, the maxillary division gives two branches:
1. Middle superior alveolar nerve.
2. Anterior superior alveolar nerve.

Middle superior alveolar nerve: Site of origin:
infraorbital canal,
Supplies adjacent mucosa of maxillary sinus; two
premolars and mesiobuccal root of first molar,
periodontal tissues, buccal soft tissue and bone in
premolar region.
Anterior superior alveolar nerve:
After it exit from the infraorbital foramen it descends
first lateral and then inferior to infraorbital canal.
provides innervation to central and lateral incisors and
the canines as well as sensory innervation to periodontal
tissues, buccal bone and buccal gingiva of these teeth.

In patients where middle superior alveolar nerve is
absent, the anterior superior alveolar nerve provides
sensory innervation to premolars and occasionally the
mesiobuccal root of first molar.
The innervation of roots of all teeth, bone and
periodontal structures are derived from terminal
branches of larger nerves. These nerves make
network; termed as dental plexus.
The superior dental plexus: These plexuses are
composed of small nerve fibers from the anterior,
middle and posterior superior alveolar nerves.

Three types of nerves emerge from these plexuses are as follows:
1. Dental nerves: enter a tooth through apical foramen dividing into many
branches within the pulp.
2. Interdental branches: Provides sensory innervation to periodontal
ligaments of adjacent teeth through alveolar bone. It then enter the
gingiva to innervate the interdental papilla and buccal gingiva.
3. Inter radicular branches: periodontal ligament at root furcations.

Branches on the Face
Infraorbital nerve emerges on the face through infraorbital foramen
and divides into its terminal branches:
Inferior palpebral: supply skin of lower eyelid with sensory
innervation to both surfaces of conjunctiva.
External nasal/lateral nasal: provides sensory innervation to skin on
lateral aspect of nose.
Superior labial: provides sensory innervation to skin and mucous
membrane of whole of upper lip

NaOCl accident causes
ecchymosis,numbness,damage to
facial vein,chances to facial nerve
paresthesia.
NaOCl was extruded from the apex of
a right maxillary lateral incisor and
infused into the periradicular
tissues,upper and lower eyelids and
angle of the mouth,orbit shows bruis
which affects superior and inferior
palpebral (eyelid) veins, anterior
facial vein is covered by the
zygomatic muscles.

a) replacing NaOCl with another irrigant; b) using a lower concentration
of NaOCl; c) placing the needle passively and avoiding wedging of the
needle into the root canal; d) irrigation needle placed 1–3 mm short of
working length; e) using a side-vented needle for root canal irrigation;
and f) avoiding the use of excessive pressure during irrigation.
acetaminophen (5mg/500mg) three times a day for 7 days
amoxicillin (500 mg) three times per day for 7 days to prevent
bacterial infection,
methylprednisolone (4 mg) three times a day for 7 days to relieve
swelling.
normal tissue appearance and
absence of sequelae were
observed after 3 weeks

Mandibular Nerve (V3)
Mandibular nerve is the largest branch and nerve of first
(mandibular) branchial arch.
And supplies the stuctures derived from that arch.
Otic and submandibular ganglions are associated with this.
It is a mixed nerve.

Sensory root of the mandibular division: It originates at the inferior
part of trigeminal ganglion in the middle cranial fossa
Motor root arises in motor cells located in pons and medulla
oblongata.
The two roots emerge from the cranium, separately through the
foramen ovale, the small motor root lying medial to sensory root.
They unite just outside or at the foramen ovale, and form the main
trunk of mandibular nerve.

Branches from Undivided Nerve
These are two branches:
Meningeal branch
Nerve to medial pterygoid.
Meningeal branch (nervus spinosus): It passes upwards and re-enters
the cranium through foramen ovale.
Here it supplies:
I. Cartilaginous part of eustachian tube
II. Middle cranial fossa; it supplies dura mater in the posterior half,
mastoid air cells.

Nerve to medial pterygoid: It sinks into the deep surface of muscle.
It has a branch that passes close to otic ganglion and supplies the two
tensor muscles, tensor velli palati and tensor tympani.

Branches from Anterior Trunk
Motor innervations to the muscles of mastication
The trunk runs forwards under lateral pterygoid muscle for a
short distance and then reaches the external surface of that
muscle by passing between its two heads. From this point it is
known as long buccal nerve (also long buccal nerve/buccinator
nerve).
 The only sensory branch of anterior trunk

Emerges under the anterior border of masseter muscle and pierces the
buccinators.
And supplies the skin of cheek, mucous membrane related to
buccinator. Also supplies labial aspect of gums molars and premolars.
While under the lateral pterygoid muscle, the nerve gives off several
branches providing motor innervation to respective muscles.
Deep temporal nerves
Nerve to masseter
Nerves to lateral pterygoid

Branches of Posterior Trunk
Primarily sensory, with a small motor component.
Branches:
i. Auriculotemporal
ii. Lingual
iii. Inferior alveolar nerve.

Auriculotemporal nerve:
It arises immediately beneath foramen ovale.
It transverses upper part of parotid gland, between the TMJ and
external auditory meatus, crosses posterior part of zygomatic arch
and ascends close to superficial temporal artery.
It has two parts:
Auricular part: supplies the
skin of tragus, upper part of
pinna, external acoustic meatus,
tympanic membrane.
Temporal part: supplies skin of
temple.

Lingual nerve:
Second branch of posterior trunk of mandibular division.
It runs anterior and medial to inferior alveolar nerve.
 deep to pterygomandibular raphe and below the attachment
of superior constrictor of pharynx, to reach the side of the
base of tongue, slightly below and behind and medial to
mandibular third molar.

It is sensory to anterior two-third of the tongue, for both general
sensation and gustation (taste) for this region
It also provides sensory innervation to mucous membrane of floor of
mouth and gingiva on lingual side of mandible.

Inferior alveolar nerve
Largest branch of mandibular division.
It runs vertically downward and laterally to
medial pterygoid and to the sphenomandibular
ligament.
Then it enters mandibular canal at the level of
mandibular foramen.
Throughout its path, it is accompanied by
inferior alveolar artery (a branch of internal
maxillary artery) and inferior alveolar vein. The
artery lies just anterior to the nerve.

The nerve divides into terminal branches at the
mental foramen:
I. Incisive nerve: Labial aspect of gums of canine
and incisors.
II. Mental nerve: Skin of chin, skin & mucous
membrane of lower lip.

Mylohyoid nerve:
Branches from inferior alveolar nerve prior to its entry into
the mandibular canal.
It runs downwards and forwards in mylohyoid groove on
medial surface of ramus and along the body of mandible to
reach the mylohyoid muscle.
It contains all the motor fibres from posterior division.
Supplies to mylohyoid muscle and anterior belly of
digastric.

GANGLIONS RELATED TO
TRIGEMINAL NERVE

OTIC GANGLION
Peripheral
parasympathetic ganglion
which relays secretomotar
fibres to parotid gland.
 it is related to
mandibular nerve
but functionally it is a part
of glossopharyngeal nerve.
Trigeminal
ganglion
Otic
ganglion

Trigeminal ganglion
Crescentic or semilunar shaped sensory ganglion of 5th nerve.
The ganglion lies on the trigeminal impression on the anterior surface
of petrous part of temporal bone near its apex and occupies a special
space of duramater called the trigeminal of Meckel’s cave.
The central process of ganglion cells form the large sensory root while
the peripheral processes of ganglion cells
forms the three divisions of trigeminal nerve.

Pterigopalatine ganglion
This is the largest parasympathetic peripheral ganglion.
Lies in the pterygopalatine fossa just below the maxillary nerve.
Topographically it is related to maxillary nerve but functionally it is
connected to the facial nerve.
Submandibular ganglion
Topographically it is related to lingual nerve but functionally it is
connected to the facial nerve.
It is the relay station for secretomotor fibres to the submandibular
and subligual gland.

Ciliary ganglion
Parasympathetic ganglion placed in cource of occulomotor nerve.
Lies near the apex of orbit.
It has sensory, motor and sympathetic roots.
1. The sensory root comes from nesociliary nerve & contains
sensory fibres from the eyeball.
2. The motor root arises occulomotor nerve. It carries preganglionic
fibres from Edinger-Westphal nucleus to supply the sphincter
pupillae and ciliaris mucle.
3. The sympathetic root carries postganglionic fibres of superior
cervical ganglion to supply the blood vessels of eye ball and the
dilator pupillae.

The patient returned to the dental office concerned
over a generalized weakness of the left side of her
face and especially her inability to close her left eye,
symptoms which appeared that same morning
expressionless appearance.
Obliteration of the nasolabial fold and drooping of
the corner of the mouth were also present.
On the attempt to smile, her mouth was drawn to the
right side

Treatment= acyclovir combined with
prednisone.
The patient should be referred to a neurologist
for further evaluation and a clinical follow-up
must be organized. The recovery is often total,
but slow and progressive.
The patient was unable to raise her left eyebrow or
close her left eyelid.
When she was prompted to close her eyes, the left
eyeball rolled upwards.

 Immediately after injection, the
patient reported blurred vision in
the right eye.
After approximately 25 to 30
seconds, an unexpected response
was observed. The patient
reported complete loss of vision.
Dental treatment was stopped
immediately.
The patient was reassured and
kept in the supine position
The tooth was sensitive to vertical
percussion; however, a delayed
response to electric pulp testing
was observed.
A periapical radiograph revealed a
deep carious lesion involving the
pulp and widening of the
periodontal ligament space at the
mesial and distal root of tooth .

Treatment= the anesthetic solution should
be slowly injected.
This would avoid injecting the solution
under pressure.
The gauge of needle used for injection
may also play an important role in this
complication.
Smaller- gauge needles are more likely to
be deflected as they pass through tissues.
The clinician can try to minimize the
potential for such complications through
effective anxiety management .

The sealant used was relatively nonneurotoxic, and although it was within the
bony confines of the canal, the sealant was not within the epineurium.
Steroids, administered to reduce edema and
inflammatory response to the sealant within the
rigid confines of the inferior alveolar nerve, may
provide some relief or allow surgeons to wait a day
or two before performing surgery.
The clinician immediately should perform decompression
and débridement, irrigation and cleaning of the nerve, which
may achieve the best results.

LA Complications
PSA Nerve Block:
 Hematoma
 Mandibular anesthesia
Anterior Superior Alveolar Nerve Block (Infraorbital Nerve Block):
Hematoma (rare) may develop across the lower eyelid and the tissues
between it and the infraorbital foramen.
Injury to eye
Nasopalatine nerve block.
Inadequate palatal soft tissue anesthesia in the area of the maxillary
canine and first premolar during nasopalatine nerve block.

Paresthesia is a neurosensitivity disorder caused by
injury to the neural tissue. It is characterized by a
burning or twinging sensation or by partial loss of local
sensitivity.
Paresthesia related to endodontic treatment can occur
because of extravasation of filling material or the
intracanal dressing, as a consequence of periapical
surgery or because of periapical infection.

Apical lesion of an endodontically treated second premolar with short obturation
was observed radiographically. Retreatment was unsuccessful at reaching the
apex; instead, swelling, pain, and extension of numbness on the region
In case of treatment-related paresthesia in which apical extrusion
of endodontic materials is observed, the need for surgical
a case of
periapical
lesion-induced
paresthesia
that was
successfully
treated
endodontically
symptoms completely
resolved within a year
after the treatment

Inferior Alveolar Nerve Block:
Hematoma
Excessive bleeding
Mental Nerve Block:
Hematoma
Paresthesia of lip and/or chin.
Contact of the needle with the mental nerve as it exits the mental
foramen may lead to the sensation of an “electric shock” or to various
degrees of paresthesia (rare).
Hematoma: bilateral mental nerve blocks.

Inferior alveolar nerve:
damaged by fracture of mandible,
 or during surgical removal of third molar(0.41-7.5%) resulting in
paraesthesia.
This can be assessed by testing sensation over the chin.
lingual nerve
In extraction of malposed wisdom tooth(0.06-11.5%) care must be
taken not injure lingual nerve.
If injury occurs there is loss of all sensation from anterior two-third of
tongue.
During extraction buccal nerve may get involved by LA causing
temporary numbness of the cheek.

Examination Of Trigeminal Nerve
1. Sensation Function
2. Motor Function
3. Corneal reflex
4. Test jaw jerk

Sensation function
Use sterile sharp object on forehead,
cheek, and jaw If any abnormality
present then go to test of thermal
sensation and light touch
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.

Test jaw jerk (masserter reflex)
Is a stretch reflex used to test the status of V nerve.
Doctor finger on tip of jaw, grip patellar hammer halfway
up shaft and tap finger lightly,
Normally patient as nothing is happens, or just a slight
closure.
Brisk in upper motor neuron lesions.

Motor examination:
The mandibular nerve is tested clinically by asking the patient to
clench her/his teeth and then filling for the contracting masseter &
temporalis muscles on the two sides.
If one masseter is paralysed, the jaw deviates to the paralysed side,
on opening mouth by the action of normal lateral pterygoid of
opposite side.
The activity of pterygoid is tested by asking the patient to move the
chin from side to side.

TRIGEMINAL NEURALGIA
Definition=
Sudden, usually unilateral, severe brief stabbing
pain in the distribution of one of more branches
of the V nerve.
Other names
Tic douloureux – Nicholaus Andre
Fothergill’s disease – John Fothergill

CLASSIFICATION:
International Headache Society (IHS);
A]Classical /idiopathic/typical B]Symptomatic
Classical trigeminal neuralgia=
1. is a unilateral disorder characterized by brief
electric, shocklike pains.
2. Abrupt in onset and termination
3. limited to the distribution of one or more
divisions of the trigeminal nerve
Symptomatic trigeminal neuralgia =
1. Pain is similar to classical type But it is caused by a
demonstrable structural lesion other than vascular
compression.

clinical feature
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.

 Rare-Middle age-Female predilection (60%)-Maxillary
division more commonly involved than opthalmic
Pain lasts for few seconds to minutes =
1. Unilateral (predominantly right side)
2. Precipitated by trigger zones

IHS diagnostic criteria;
A. Paroxysmal attacks of facial or frontal pain that last a few seconds to
less than 2 minutes, affecting one or more divisions of the trigeminal
nerve and criteria B and C.
B. Pain has at least one of the following characteristics:
1.Intense, sharp, superficial or stabbing
2. Precipitated from trigger areas or by trigger factors
3. The patient is entirely asymptomatic between paroxysms.
C. Attacks are stereotyped in the individual patient.
D. There is no clinically evident neurological deficit.Not attributed
to another disorder.

DIAGNOSIS
History
Clinical examination
Diagnostic LA blocks
CT scan
MRI

Sweet diagnostic 5 major criteria:
1. The pain is paroxysmal
2. The pain may be provoked by light touch to the face (trigger
zones)
3. The pain is confined to trigeminal distribution
4. The pain is unilateral
5. The clinical sensory examination is normal

Surgical management
Surgical options have been reserved for those patients
1. who have a clearly defined secondary cause for the
trigeminal neuralgia,
2. who are unresponsive,
3. who have severe, unremitting pain that limits their
ability to eat,
4. for whom multiple medications are intolerable or
contraindicated

TREATMENT:
Medical treatment
Surgical treatment:
1. Peripheral injections
2. Gamma knife surgery
3. Peripheral neurectomy
4. Cryotherapy
5. Peripheral radiofrequency
6. Neurolysis(thermocoagulation)
7. Gasserian ganglion procedures

Carbamazepine and phenytoin are the traditional anticonvulsants.
initially dose should be kept small to minimum especially in elderly
patients to avoid nausea, vomiting and gastric irritation.
Once the pain remission has being achieved the drug dose should be
kept at maintainance level or withdrawn and restarted if symptoms
reappear
When carbamazepine is contraindicated clonazepam can be given
Co-administration of phenytoin or baclofen is also advocated.
Medical treatment

Surgical treatment
Peripheral Nerve Injections:
Long acting anesthetic agents: without adrenaline bupivacaine
with or without corticosteroids.
The selective nerve blocks can be given as an emergency measure,
where the patient is suffering quite a lot.
Alcohol injections:
The intraoral injection of 95% absolute alcohol in small quantities
(0.5 to 2 ml).
Repeated alcohol injections should be avoided, as it causes local
tissue toxicity, inflammation and fibrosis.

The results are variable. Sometimes it provides relief for a period of 6
to 12 months or sometimes patient comes back with pain immediately
within short time span.

Gamma knife radiosurgery
The Gamma Knife is a focused 201 intercepting beams of
gamma radiation, produced by separate cobalt sources.
1. The dose is 70–90 Gy.
2. Pain relief is usually not immediate.
3. The mean time to pain relief in two series was
approximately one month.

Peripheral neurectomy (nerve Avulsion) :
Oldest and the most effective procedure
Simple
Relatively reliable
Indicated in patients in whom craniotomy is contraindicated due to
age, debility, limited life expectancy.
Acts by interrupting the flow of a significant number of afferent
impulses to central trigeminal apparatus.
Performed mostly on infraorbital, inferior alveolar, mental and
rarely lingual nerve.
It has a disadvantage of producing full anesthesia or deep
hypoesthesia related dysfunction.

Cryotherapy:
Direct application of cryotherapy probe (nitrous oxide probe)
Temperature colder than -60 ºC for 2-3 minutes
Repeated three times

Peripheral radiofrequency neurolysis thermocoagulation:
Radiofrequency electrode that has the capacity to destroy the pain
fibres is used in this procedure.
Temperature being 65 to 75 ºC for 1 to 2 minutes.
Shown to induce pain remissions in 80% of cases.
Advantages: Low morbidity in high risk/ elderly patients.

GASSERIAN GANGLION PROCEDURS:
Includes various procedures:
1.Gycerol injection
2.Thermocoagulation
3.Ballon compression

GYCEROL INJECTIONS:
Absolute alcohol or phenol-glycerol mixture can be used as the
neurolytic agents.
Agent is injected into meckel’s cave or in the ganglion.
It induces pain relief in 80% of the cases.
Also spares the ophthalmic division and the motor root. .

THERMOCOAGULATION:
A radiofrequency electrode that has the capacity to destroy pain fibres
is used.
Alternating currents of high frequency is passed through the
electrode.
It produces ionization in biological tissues leads to coagulation of
tissues.

BALLON COMPRESSION:
A Fogarty catheter 1 to 2cm is advanced within the meckel’s cave
through foramen ovale.
Inflated upto 0.75ml at the ventral aspect of the ganglion root for 1
minute.
It destroys the root fibres.

Trigeminal Neuralgia Diet
1. Low fat, high protein, high calorie
2. Easy chewable foods
Trigeminal Neuralgia Association recommend avoidance of:
avoiding things such as caffeine, citrus fruits and bananas.
extreme hot/cold, hot sauce,chili, spicy salsa, mints, black
pepper,cinnamon, ginger, nutmeg

The diagnosis and management of nerve injury
during endodontic treatment
Mechanical nerve injuries during endodontic treatment may be
classified Neuropraxia (cases in which there is a brief altered
sensation); Axonotmesis (partial damage to the nerve fibers that
may fully recover within 2– 12 months); and Neurotmesis (a
nerve that has been entirely cut, with poor prognosis for recovery)
Diagnosis of endodontic treatment-related nerve injury=
Periapical radiography, treatment planning, and for the
management of endodontic complications, computed tomography
scans.

Diagnosis and management of suspected nerve injury following an endodontic
treatment.
(1)Non-routine sequel: any event that is not part of the routine and/or expected
sequel during or following the endodontic procedure.
(2) Suspected altered sensation: any event that occurred during or following
the endodontic procedure, was reported by the patient, or is suspected based on
clinical and/or radiographic evaluation, which may suggest the presence of
altered sensation following the endodontic procedure.
(3) Clinical evaluation: evaluation performed to determine the presence, nature,
and extent of the sensory disturbance.

(4) Definitive/non-definitive diagnosis: the practitioner is
able/unable (respectively) to determine the presence, nature, and
extent of the suspected altered sensation; OR is able/unable
(respectively) to determine the required treatment and/or to
monitor recovery.
(5) Early intervention: an intervention performed even prior to
a definitive diagnosis, aimed at preventing permanent nerve
damage and enabling a better clinical and medico-legal response

Para trigeminal or Readers syndrome:
characterized by severe, unilateral facial pain and headache
in the distribution of the ophthalmic division of the
trigeminal nerve
in combination with ipsilateral oculosympathetic palsy or
Horner syndrome.
UNIlateral pain of head without vasomotor disturbances.

Frey syndrome / Gustatory sweating:
First described by frey.
It is localised gustatory sweating in the area supplied by
auriculotemporal nerve.
It arries as a result of damage to auriculotemporal nerve and subsequent
innervation of sweat glands by parasympathetic salivary fibres.
The patient typically exhibits flushing and
sweating of the involves side of the face,
chiefly in temporal area, during eating.

It can be commonly seen in:
Penetrating wound of the parotid region
Parotid surgery
Mandibular & Zygomatic bone fractures
TMJ surgery

Treatment:
Botox injection: reduce sweating
Topical anti- perspirant (20% aluminium chloride solution)
Application of an ointment containing an anti-cholinergic drug such
as 3% scopolamine
Blockage of parasympathetic outflow by way of alcohol injection or
2%
lignocaine injections at various sites such as the otic ganglion &
the auriculo-temporal nerve.
 Partial parotidectomy.

Trotter syndrome:
In nasopharyngeal carcinoma, the tumor may extend laterally and
involve the sinus of Morgagni involving the mandibular nerve.
This produces a triad of symptoms known as Trotter's Triad.
These symptoms are:
1) Conductive deafness (due to eustachian tube involvement)
2) Ipsilateral immobility of the soft palate
3) Trigeminal neuralgia

In injury to:
 Opthalmic nerve: loss of corneal blink reflex.
Maxillary nerve: loss of sneeze reflex. As it is a afferent path for
sneeze reflex.
Mandibular nerve: loss of jaw jerk reflex.
A lesion of foramen ovale leads to paraesthesia along mandible,
tongue, temporal region and paraesthesia of mucles of mastication.

Trigeminal nerve injury also occur due to:
Ridge augmentation surgery
Endodontic surgery
Tumor resection
Salivary gland and duct surgeries(Stone in the submandibular gland
duct)
Biopsy procedures
Orthognathic surgery: BSSO highest incidencce of neurosensory
disturbances.

Maxillofacial trauma:
Fracture of mandibular body and ramus
LeFort fractures
Fracture of condylar segment medially
Mandibular angle, body and symphysis fracture
Pathologic lesions:
Surgical removal
Use of Carnoy’s solution

Conclusion
Since Trigeminal nerve is mixed nerve, supplies mainly head and neck
region.
Hence as a dentist one should know throughly about intracranial and
extracranial course and distribution of Trigeminal nerve,
 Diagnose the pathologies associated with Trigeminal nerve and for
appropriate treatment.

REFERENCES
 Human anatomy,head neck face chaurasia
 Textbook Oral and maxillofacial surgery Neelima malik
 Local anaesthesia- malamed
 Damage to the inferior alveolar nerve as the result of root canal therapyM.
Anthony Pogrel, DDS, MD, FRCS, FACS
 Severe Facial Ischemia After Endodontic Treatment Peter Lindgren, MD, DDS,*
Karl-Fredrik Eriksson, MD, PhD,† and Anita Ringberg, MD, PhD‡
 Endodontic-related Paresthesia: A Case Report and Literature Review Maria
Ahonen, DDS,* and Leo Tj€aderhane, DDS, PhD*†
 Amaurosis, an Unusual Complication Secondary to Inferior Alveolar Nerve
Anesthesia: A Case Report and Literature Review Rahul Pandey, MDS,*
Nivedita Dixit, MDS,† Kuldeep K*

 Permanent mimic musculature and nerve damage caused by sodium
hypochlorite: a case report Matthias Pelka, DMD,a and Anselm
Petschelt, DMD,b Erlangen, Germany
 Hematoma - A Complication of Posterior Superior Alveolar Nerve
Block Nidhi Gupta1, Kunwarjeet Singh2* and Sidarth Sharma3
 Endodontic-related inferior alveolar nerve injuries: A review and a
therapeutic flow chart R. Castro c,b,*, M. Guivarc’h b, J.M. Foletti
a, J.H. Catherine a,b, C. Chossegros c, L. Guyot a

Trigeminal Nerve And Endodontics

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