The facial nerve carries motor, secretory and sensory fibers. It originates in the pons and has crossed and uncrossed fibers in the facial nucleus. Damage to the facial nerve can occur at different locations and causes varying symptoms depending on if it is an upper or lower motor neuron lesion. Treatment options depend on the severity and chronicity of the injury and include medications, physiotherapy, nerve grafting and transfers. Microsurgical techniques may allow for primary repair of acute injuries or cross facial nerve grafts for more longstanding paralysis.

1. Facial
Nerve
Injuries
MALAAK JAMAL

2. The facial nerve - cranial nerve VII carries :
(1) motor
(2) secretory,
(3) afferent fibers from the anterior two thirds of the tongue.
It originates in the facial nucleus, which is located at the caudal pontine area. and the
Corticobulbar fibers from the precentral gyrus (frontal lobe) project to the facial nucleus, with
most crossing to the contralateral side. As a result, crossed and uncrossed fibers are found in
the nucleus.
the facial nucleus can be divided into two parts:
(1) the upper part, which receives corticobulbar projections bilaterally and later courses to the
upper parts of the face, including the forehead,
(2) the lower part, the predominantly crossed projections of which supply innervation to lower
facial muscles : stylohyoid, posterior belly of digastric, buccinator, and platysma
“The facial nerve”

3. “Intra Cranial part”
The portion of the nerve from the brainstem to the internal auditory canal
Carries preganglionic parasympathetic fibers and special afferent sensory
fibers
Important branches of facial nerve in
this part
(1)Greater superfacial petrosal
nerve :
Carries parasympathetic fibers to
lacrimal gland and glands of the nose and
palate.
(2)Nerve to Stapedius muscle
(3)Chorda tympani :
carries parasympathetics to the
submandibular and sublingual glands &
Taste to anterior 2/3 of the tongue .
“Intra Temporal part”

4. Main trunk 15-20 mm :
(1)Give branches to the posterior belly of the digastric and stylohyoid
muscles.
(2)Postauricular to occipitofrontalis muscles
The facial nerve branches off to smaller nerves and muscles that go
to 5 different parts of the face.
Therefore, when the nerve is damaged those smaller veins are not
supplied with enough blood for circulation which is necessary for
muscles on the different areas of the face to move.
Each nerve branch affects the movement of different muscles.
“Extra Cranial part”

5. Branching of the extracranial segments in the parotid gland that splitting it
into a superficial and deep lobe :
3. Buccal Branch - (Infraorbital
Branches): This Nerve Branch
affects the Cheek and Above the
Mouth Muscles.
4. Marginal Mandibular Branch: This
Nerve Branch affects the Chin
Muscles.
5. Cervical Branch: This Nerve
Branch some of the Neck Muscles.
1. Temporal Branch - (Frontal Branch): This Nerve Branch affects the muscles in the
Forehead.
2. Zygomatic Branch - (Malar Branches): This Nerve Branch affects the Upper Cheek.
1&2. Temporal & Zygomatic Branch: Together these Nerve Branches affect the muscles
control opening and closure of the Eye.

6. • Endoneurium
– Surrounds each axon
– Adherent to Schwann cell layer
– Vital for regeneration
• Perineurium
– Encases endoneural tubules
– Tensile strength
– Barrier to infection
• Epineurium (nerve sheath)
– Outermost layer
– Houses vasa nervosum for nutrition
“component of nerve fibers”

7. • Nerve injury is most serious
complication that may occur
during oral surgical procedures
especially when we are
damaging large nerve
branches such as during:
• dental injections , RCT ,
insertion of dental implants ,
extraction of teeth & other
surgical treatments ...etc.
“Nerve Injuries”

8. “Sunderland Nerve Injury Classification”
Class I (Neuropraxia):
-Axon remain intact
-Conduction block caused by cessation(stoping) of axoplasmic flow
-Full recovery
Class II (Axonotmesis):
-Axons are disrupted
-Endoneural tube still intact
-Full recovery expected
Class III (Neurotmesis):
-Neural tube is disrupted Injury to endoneurium or myelin sheath
-Poor prognosis
-If regeneration occurs, high incidence of synkinesis (involuntary movement of muscles
associated with voluntary movement other muscles )
Class IV (Partial transection)
-Epineurium remains intact
-Perineurium, endoneurium, and axon disrupted
-Poor functional outcome with higher risk for synkinesis.
Class V (Complete transection)
-Complete disruption
-Little chance of regeneration
-Risk of neuroma formation

9. “Causes of Facial nerve paralysis”
supranuclear lesions UMN :
• Congenital abnormalities, stroke ,
malignancies, trauma , vascular conditions and
other causes .
• only lower part of the opposite side of the face
is paralyzed.
• The upper part with the frontalis and orbicularis
oculi escapes due to bilateral representation in
the cerebral cortex.
infranuclear lesions LMN :
• Malignancy (parotid gland as well as tumors of
adjacent structures) , trauma, infections, Bell’s
palsy, osteopetrosis and iatrogenic causes .
• the whole of the face of the same side gets
paralyzed.

10. LMN LESIONS UMN LESIONS
Only lower 2/3 rd of the
facial muscles are
affected.
Mid face is paralysed.
Eye brow’s can move
normally.
Totally half side of the is
affected.
Half of the Mid face is
only paralysed.
Eye brow’s can’t move
normally.

11. “Signs and symptoms of facial nerve
paralysis”
The symptoms according to the level of injury of facial nerve.
At internal auditory meatus:
loss of lacrimation, stapedial reflex, taste from most of anterior
two-third of tongue, lack of salivation and paralysis of muscles of
facial expression.
Below geniculate ganglion:
loss of stapedial reflex, taste from anterior two third of tongue,
lack of salivation and paralayis of facial expression muscles.
Region below stylomastoid foramen paralysis of facial
expression muscles.
Sign & symptoms :
unilateral facial
weakness
loss of taste
decreased salivation and tear secretion
Hyperacusis-A heightened sensitivity to some sounds.
Facial palsy : caused by trauma, infection, tumour to the facial nerve .

12. “Dental Etiology”
1. During nerve block of IAN & Mental nerve ( deep dental injection ) .
2. While creating incision extend to mental formen & lingual vestibuler fold
3. during incision at the alveolar ridge of edentolous pt whose mental
foramen located superficially due to bone resoption
4. during excessive flap retraction
5. when bone near the nerve is excessively heated ,if the surgical
handpiece used without coolent ( water or saline solution )
6. in case of removel impacted tooth , root & root tips that are deep in the
bone which is near the nerve.
7. during perforation & fracture of lingual cortical plate during sectioning of
the roots and crown of impacted 3rd moler.
8. when a bur enters the mandibuler canal , during sectioning.
9. during displacement of a root tip inside the mandibuler canal during
extraction attempt.
10. during cleaning of periapical lesion oa posterior teeth that are in direct
contact with mand. canal .
11.or by chance Suturing of the Nerve .
12.during putting implant
13.during endodontic treatment because of proximity of the tooth to IAN by
over-instrumentation or overfilling or irrigation.

13. “Facial nerve paralysis”
BELL’S palsy :
It is the commonest type of facial palsy.
It is the major cause of the acute facial nerve
paralysis.
It affects totally half side of the face due to the
LMN Lesion.
Its idiopathic
Its due to the inflammation of the facial nerve.
The inflammation prevents nerve from
sending correct signals to brain &facial
muscles.
Sign & symptoms :
droopy eyelid, drooping corner of the
mouth,unilateral facial,weakness loss of taste
decreased salivation and tear secretion

14. “DIFFERENCE BETWEEN
FACIAL PALSY&BELL’S PALSY”
FACIAL PALSY BELL’S PALSY
1)Cause can be known
(infection,trauma, tumour).
2)Permanent(lasts for years to life).
3)need surgical treatment.
4)Site of affection depends upon
UMN&LMN Lesions.
1)It is idiopathic(may de
velop suddenly).
2)Temporary(permanent cure with
in 3 months in 90% of cases).
3)Without treatment or surgery
regains facial function.
4)It is mainly due to LMN
Lesions.half side of the face is
totally affected.

15. Herpes zoster virus
reactivation of virus within dorsal root ganglion of facial nerve is associated with
vesicles affecting ear canal.
Symptoms
1)ear pain
2)vesicles
3)hearing loss
4)vertigo
Treatment
1)anti viral
2)steroids(corticosteroids)
Otitis media
inflammation of the middle ear due to infections can spread to facial nerve &inflame it
causing compression.
Symptoms
1)ottorrhoea(discharge).
2)otalgia(no ear pain).
Treatment –myringotomy(incision to tympanic membrane)
“INFECTION”

16. 1)fractures of temporal bone due to injury in
accidents.
2)birth injury to the facial nerve at the time
of delivery due to application of fore ceps.
reason :it remains unprotected after its exit
through stylomastoid foramen
investigation CT Scan
“TRAUMA”
“TUMOR”
The bells palsy may be due to tumour’s which compress the the nerve alo
BELL’S PALSY DUE TO COMPRESSION
investigation
1)Tomography.
2)MRI(to locate tumour)
3)CT Scan

17. Used to assess the degree of electrical dysfunction and to pinpoint
the site of injury also it help to determine treatment to predict
recovery of function – partial paralysis is a much better prognosis
than total paralysis
“Facial Nerve Testing and Diagnosis ”
Topographictests
Tests function of specific facial nerve branches
Do not predict potential recovery of function
Rarely utilized today
Electrodiagnostictests
Utilize electrical stimulation to assess function
Most commonly used today
Magnetic stimulation of intra-cranial facial nerve
CT scan temporal bone: for progressive palsy
MRI brain
Surgical exploration
Tests for faAsk the patient to show his teeth.
 Ask the patient to puff his cheeks.
 Ask the patient to close his eyes against resistance.
 Ask the patient to lift his eyebrows.cial palsy:
 Ask the patient to lift his eyebrows

18. Depends on the age of patient , type of the damage , time
that elapsed till the management of injury , correct treatment
“Prognosis”
“Treatment”
• No treatment required for type 1 & 2 unless if there foreign
body or root tip compressing on the nerve we just prescribe
analgesic & vitamin B to restore the sensation .
• Treatment of the neaurotmesis is grafting to replace the
injured part or suturing .
• For bell’s palsy is often treated with the corticosteriod

19. “Treatment AND Medication”
• Oral antivirals - Acyclovir
• Corticosteroids
• Eye protection
• Follow progression with serial exams
• Physiotherapy
• If the patient is seen within 2 to 3 weeks of onset of symptoms-tab.
Prednisolone in doses of 1mg/kg/d for 10 to 14 days has been
recommended with a gradual tapering.
• Vitamins B1, B6, B12 may be administered.
• If pt is seen after 3-4 weeks, then steroid therapy is of no use.
“SURGICAL TREATMENT MODALITIES”
• Nerve decompression - Internally or externally
• Nerve anastomosis
• Nerve grafting

20. A. Acute (< 3 wks)
1. Nerve exploration/decompression
2. Nerve repair
a. Primary anastomosis
b. Cable grafting
i. Great auricular nerve
ii. Sural nerve
B. Intermediate (3 wks- 2 yrs)
1. Nerve transfer
a. Hypoglossal-facial
b. Spinal accessory-facial
c. Masseteric-facial
2. Cross face nerve grafting using sural
nerve
C. Chronic (>2 yrs)
1. Muscle transfers
a. Temporalis
b. Masseter
c. Digastrics
2. Free muscle flaps/ microneurovascular
transfer
a. Gracilis
b. Latissimus dorsi
c. Serratus anterior
d. Pectoralis minor
D. Static procedures/ancillary procedures
(can be performed at any time period listed
above)
1. Gold weight/spring implants
2. Slings
3. Lid procedures
“SURGICAL TREATMENT MODALITIES”

21. Facial nerve repair is the
most effective procedure to
restore facial function in
patients who have suffered
nerve damage from an
accident or during surgery.
It involves microscopic repair
of a nerve that has been cut.
“Micro-neurological Surgery”

22. End-to-end anastomosis
preferred No tension
Extratemporal repair
performed < 72 hrs of injury
Most common methods
 Group fascicular repair
 Epineural repair
“PRIMARY NERVE REPAIR”
Group fascicular repair

23. 1. Parotidectomy incision extended into cervical
crease ~ 2-3 cm below inferior border of
mandible
2. Facial nerve identified and dissected distal to pes
anserinus
3. Identify hypoglossal nerve
a. SCM retracted posteriorly
b. Dissect superiorly until posterior belly of
digastic is identified
c. Retract digastric superiorly and CN XII is
found inferiorly.
d. Hypoglossal is within
2-3 c m of main trunk of the facial nerve
4. Hypoglossal nerve is dissected anteriorly and
medially into the tongue.
1. Transect distal to ansa hypoglossis
5. Facial nerve transected at the stylomastoid
foramen
6. Anastomose nerves using 9-0 epineural suture.
Hypoglossal-Facial Technique
Hypoglossal Facial Nerve Transfer

24. “Treatment”
 Brow ptosis correction – direct brow lift,endoscopic brow lift.
 Eye lid weight placement – occuloplastic management for lagopthalmus.
 Static facial suspension – by using facial slings from zygomatic/temporalis arch to
nasolabial fold & oral commisure.
 Extra nasal valve repair – facia lata sling from alar base to temporalis facia to open
extra nasal valve.
 Cross Face Nerve Transplant(CFNT) – It is most advanced.
 It is making continuity between paralysed&normal facial nerves by means of bridge
grafts.

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