2. Contents
1.
2.
3.
4.
5.
6.
7.
8.
Introduction
Embryology
Nuclei of origin
Course & Relations
Branches of facial nerve
Functional components
Ganglia associated with facial nerve
Blood supply

3. 10.Variations of nerve
11.Testing of facial nerve
12.Identification of facial nerve
13.Complications of facial dissection
14.Facial nerve lesions
15.Acquired & Congenital anomalies

4. Introduction
 The Facial nerve is the seventh of twelve paired cranial
nerves, it is a mixed nerve with motor and sensory roots.
 It emerges from the brain stem between the pons and the
medulla, controls the muscles of facial expression
 It functions in the conveyance of taste sensations from
the anterior two thirds of the tongue and oral cavity
 It also supplies preganglionic parasympathetic fibres to
several head and neck ganglia

5. Embryology
 The facial nerve is developmentally derived from the
hyoid arch, which is the second branchial arch
 The motor division of facial nerve is derived from the
basal plate of the embryonic pons
 The sensory division originates from the cranial neural
crest

6.  Facial nerve course, branching pattern, and anatomical
relationships are established during the first 3 months
of prenatal life
 The nerve is not fully developed until about 4 years of
age
 The first identifiable Facial Nerve tissue is seen at the
third week of gestation- facioacoustic primordium
or crest

7. Facial nerve embryology: 4th week
 By the end of the 4th week,
the facial and acoustic
portions are more distinct
 The facial portion extends
to placode
 The acoustic portion
terminates on otocyst

8. Facial nerve embryology: 5th week
 Early 5th week, the
geniculate ganglion
forms from distal part
of primordium
 It separates into 2
branches: main trunk
of facial nerve and
chorda tympani

9. Facial nerve embryology: 6th week
 Near the end of the 5th
week, the facial motor
nucleus is recognizable
 The motor nuclei of VI
and VII cranial nerves
initially lie in close
proximity.
 The internal genu
forms as
metencephalon, it
elongates and CN VI
nucleus ascends

10. Facial nerve embryology: 7th week
 Early 7th week, geniculate ganglion is well-defined and
facial nerve roots are recognizable
 The nervus intermedius arises from the ganglion and
passes to brainstem. Motor root fibers pass mainly
caudal to ganglion

11.  Proximal branches form in the 6th week, posterior
auricular branch, branch of digastric
 Early 8th week,
temporofacial and cervicofacial divisions present
 Late 8th week,
5 major peripheral subdivisions present

12. Nucleui of Origin
1. Motor nucleus of facial nerve (SVE):
It lies in the lower part of the pons
2. Superior salivatory nucleus (GVE):
It lies in the pons lateral to the main motor nucleus
of VII and gives rise to secretomotor
parasympathetic fibers that pass in greater
superficial petrosal nerve and chorda tympani.

13. 3. Nucleus solitarus (SVA):
It lies in the medulla, receives the taste sensation
from the anterior 2/3 of the tongue via the central
processes of the cells of the geniculate ganglion of the
facial nerve
4. GSA fibers :
Through these fibers to acoustic meatus & back of
auricle through communication from auricular
branch of vagus. These fibers terminate in main
sensory nucleus & spinal nucleus of 5 th nerve

14. Facial nerve origin

15. COURSE OF FACIAL NERVE
Internal course: the motor fibres passes dorsally and
medially forming a loop around the abducent nucleus in
the floor of the 4th ventricle forming facial colliculus
Superficial origin: at the pontomedullary angle above
the inferior cerebellar peduncle.

16. The facial nerve is formed mainly of two parts:
1- Facial nerve proper (motor): arising from facial
motor nucleus in pons.
2- Nervus intermedius: it is the sensory root of facial
lies position between the facial proper and
vestibulcochlear nerve in the pontocerebellar angle.
Carrying para-sympathetic fibers (from superior
salivary nucleus) and taste fibers ( to the solitary
nucleus).

17. Course and relations:
I- Intracranial (intrapetrosal) course
II- Extracranial course

18. I- The intrapetrous course:
The nerve passes laterally with the vestibulocochlear
nerve (CN VIII) to the internal auditary meatus. At the
bottom of the meatus the nerve enters the facial bony
canal where it runs laterally above the vestibule of inner
ear.
Reaching the medial wall of the middle ear, it bends
sharply backwards above the promontory (forming its
genu) where the genicular ganglion is found
It then arches downwards in the medial wall of the
middle ear to reach the stylomastoid foramen.

24. II- Extracranial course:
 As it emerges from the stylomastoid foramen, it runs
forwards in the substance of the parotid gland
crosses the styloid process, the retromandibular vein
and the external carotid artery.
 It divides behind the neck of the mandible into its
terminal branches which come out of the anteromedial
surface of the gland.

26. Branches
Intracranial
Greater petrosal nerve
Nerve to stapaedius
Chorda tympani
Intratemporal
Intrameatal
Labyrinthine
Tympanic
Mastoid nerve

27. Extracranial
Posterior Auricular Nerve
Digastric nerve
Stylohyoid nerve
The five terminal branches
Temporal branch
Zygomatic branch
Buccal branch
Marginal mandibular branch
Cervical branch

30.  Within the facial canal:
1- Nerve to stapedius: supplies the stapedius muscle.

2- Greater superfacial petrosal nerve (GSPN) : arises
from the genicular ganglion
The greater superficial petrosal nerve joins the deep petrosal
nerve from the sympathetic plexus on the internal carotid
artery in carotid canal to form the nerve of the pterygoid
canal (vidian nerve) which passes through the pterygoid
canal to the pterygopalatine fossa and ends in the pterygopalatine ganglion

31. 3- Chorda tympani nerve:
 It arises from the facial nerve 6 mm above the
stylomastoid foramen and runs upwards to perforate
the posterior bony wall of the tympanic cavity.
 It then passes forwards on the medial surface of the
tympanic membrane between its fibrous and
mucous layers crossing the handle of the malleus.

32.  It comes out of the tympanic cavity through the
petrotympanic fissure to the infratemporal fossa
where it joins the lingual nerve.
 Through the lingual nerve, it supplies both the
submandibular and sublingual salivary glands by
secretomotor fibres and taste fibers from the
anterior 2/3 of the tongue

33. II- At the exit from the stylomastoid foramen
1- Posterior auricular nerve:
to the auricularis posterior and the occipital belly of
the occipitofrontalis muscle.
2- Digastric branch:
to the posterior belly of digastric muscle
3- Stylohyoid branch:
to the stylohyoid muscle

34. TERMINAL BRANCHES
The temporal branches of the facial nerve (frontal
branch of the facial nerve) crosses the zygomatic
arch to the temporal region, supplying the
auricularis anterior and superior, and joining with
the zygomaticotemporal branch of the maxillary
nerve, and with the auriculotemporal branch of the
mandibular nerve.

35. The more anterior branches supply the frontalis, the
orbicularis oculi, and corrugator supercilii, and
join the supraorbital and lacrimal branches of the
ophthalmic.
The temporal branch acts as the efferent limb of the
corneal reflex.

36. The zygomatic branches of the facial nerve (malar
branches) run across the zygomatic bone to the
lateral angle of the orbit.
Here they supply the Orbicularis oculi, and join with
filaments from the lacrimal nerve and the
zygomaticofacial branch of the maxillary nerve.

37. The Buccal Branches of the facial nerve
(infraorbital branches), of larger size than the rest
of the branches, pass horizontally forward to be
distributed below the orbit and around the mouth.

38. The buccal branch supplies these muscles
MUSCLE
ACTION
Risorius
Smile
Buccinator
Aids chewing by holding cheeks flat
Levator Labii Superioris
Elevates upper lip
Levator labii superioris alaeque nasi
Snarl
Levator Anguli Oris
Soft smile
Nasalis
Flare Nostrils
Orbicularis oris muscle
Purse Lips
Depressor Septi Nasi
Depresses Nasal Septum
Procerus
Moves Skin of Forehead

39.  The marginal mandibular branch of the facial
nerve passes forward beneath the platysma and
depressor anguli oris.
 It supplies the muscles of the lower lip and
chin, and communicating with the mental
branch of the inferior alveolar nerve.

40.  The cervical branch of the facial nerve runs
forward
 It forms a series of arches across the side of the
neck over the suprahyoid region.
 One branch descends to join the cervical
cutaneous nerve from the cervical plexus; others
supply the Platysma. Also supplies the
depressor anguli oris.

44. Branches
Branches of
communication
Branches of distribution

45. Branches of Communication
Internal acoustic meatus
Geniculate ganglion
Vestibulocochlear nerve
A. Greater petrosal nerve
B. Lesser petrosal nerve
C. External petrosal nerve
Facial canal
Stylomastoid foramen
Vagus nerve
IX & X cranial nerve
Greater auricular nerve
Auriculotemporal nerve
Behind ear
Lesser occipital
Face
Neck
V nerve
Transverse cutaneous nerve

48. Branches of Distribution
Facial canal
A. Nerve to stapedius
B. Chorda tympani
Stylomastoid
foramen
A. Posterior auricular
B. Nerve to
stylohyoid
C. Nerve to digastric
(posterior belly)
In face
A.
B.
C.
Temporal
Zygomatic
Buccal
D.
Marginal
mandibular
E.
Cervical

49. Facial Nerve: Functional Components
 Special Visceral Efferent/Branchial Motor
 General Visceral Efferent/Parasympathetic
 General Sensory Afferent/Sensory
 Special Visceral Afferent/Taste

50. Special Visceral Efferent/Branchial Motor
 Premotor cortex  motor cortex 
corticobulbar tract  bilateral facial motor
nuclei (pons)  facial muscles
 Stapedius, stylohyoid, posterior
digastric, buccinator

52. General Visceral Efferent/Parasympathetic
Superior salivatory nucleus (pons)
nervus intermedius
greater/superficial petrosal nerve
facial hiatus/middle cranial fossa
joins deep petrosal nerve (symp fibers from cervical plexus)
through pterygoid canal (as vidian nerve)
pterygopalatine fossa
spheno/pterygopalatine ganglion
postganglionic parasympathetic fibers
joins zygomaticotemporal nerve(V2)
lacrimal gland & seromucinous glands of nasal and oral cavity

53. Superior salivatory nucleus
nervus intermedius
chorda tympani
joins lingual nerve
submandibular ganglion
postganglionic parasympathteic fibers
submandibular and sublingual glands

54. General Sensory Afferent/Sensory
Sensation to auricular concha, EAC wall, part
of TMJ, postauricular skin
Through Cell bodies in geniculate ganglion

55. Special Visceral Afferent/Taste
Postcentral gyrus
nucleus tractus solitarius
nervus intermedius
geniculate ganglion
chorda tympani
joins lingual nerve
anterior 2/3 tongue, soft and hard palate

57. GANGLIA ASSOCIATED
WITH THE FACIAL NERVE
Geniculate ganglion
Submandibular ganglion
Pterygopalatine ganglion

58. Geniculate Ganglion
The geniculate ganglion (from Latin genu, for "knee") is
an L-shaped collection of fibers and sensory neurons
of the facial nerve located in the facial canal of the head.
It receives fibers from the motor, sensory, and
parasympathetic components of the facial nerve and
sends fibers that will innervate the lacrimal glands,
submandibular glands, sublingual glands, tongue,
palate, pharynx, external auditory meatus, stapedius,
posterior belly of the digastric muscle, stylohyoid
muscle, and muscles of facial expression.

60. Submandibular Ganglion
 The submandibular ganglion is small and fusiform
in shape. It is situated above the deep portion of the
submandibular gland, on the hyoglossus muscle,
near the posterior border of the mylohyoid muscle.
 The ganglion 'hangs' by two nerve filaments
from the lower border of the lingual nerve (itself a
branch of the mandibular nerve, CN V3). It is
suspended from the lingual nerve by two filaments,
one anterior and one posterior. Through the
posterior of these it receives a branch from the
chorda tympani nerve which runs in the sheath of
the lingual nerve.

62. Pterygopalatine Ganglion
The pterygopalatine ganglion (meckel's ganglion,
nasal ganglion or sphenopalatine ganglion) is a
parasympathetic ganglion found in the pterygopalatine
fossa.
It's largely innervated by the greater petrosal nerve
(a branch of the facial nerve); and its axons project to
the lacrimal glands and nasal mucosa

64. Facial Nerve blood supply
The facial nerve gets it’s blood supply from 4 vessels:
 Anterior inferior cerebellar artery – at the
cerebellopontine angle
 Labyrinthine artery (branch of anterior inferior
cerebellar artery) – within internal acoustic meatus
 Superficial petrosal artery (branch of middle
meningeal artery) – geniculate ganglion and nearby
parts

65.  Stylomastoid artery
(branch of posterior auricular artery) – mastoid
segment
 Posterior auricular artery supplies the facial
nerve at & distal to stylomastoid foramen
 Venous drainage parallels the arterial blood
supply

66. Variations of Facial Nerve
1. Buccal branch usually single, two branches in 15%
cases
2. Marginal mandibular branch – pass bellow the lower
border of mandible, incidence varying between 20-50%
3. Cervical branch – 20% cases, two branches

4. Katz and Catalano reported cases (3%) presenting two
main trunks, known as the major and minor trunks of facial nerve.

5. Baker and Conley reported trifurcation,
quadrifurcation, or even a plexiform branching pattern of
the trunk of the facial nerve

67. Patterns of branching of Facial Nerve
Classified by Davis et al (1956)

68. 1. Type I facial nerve (straight branching) with variations.
Type IA
I). Zygomatic sending a loop to itself
ii). Absent zygomatic loop
Type IB
iii). Buccal nerve arising from upper
division & mandibular sending a loop to itself
iv). Mandibular loop is absent.

70. Type II facial nerve major connection between
buccal & zygomatic nerves

71. Type III facial nerve with major connection between
buccal & any other nerve.
Type IIIA
i). Anastomosis between zygomatic & buccal nerve
ii). between buccal & upper division
iii). between buccal and lower division
Type IIIB
iv). between buccal nerve (arising from mandibular) &
zygomatic nerve
Type IIIC
v) Connection between buccal & marginal mandibular
vi). Connection between buccal nerve arising from
upper division & lower division .
vii). Type III C with additional anastomosis between upper &
lower divisions .

73. Type IV Complex branching pattern.
Type IVA
i). Buccal nerve arising from upper division
ii). No anastomosis between buccal nerve & upper
division (V).
TYPE IVB
iii). Buccal nerve arising from both division.
iv). Buccal nerve arising from upper division only (V).

75. Type V Two main trunks.
i). Type VA
upper & lower division arising from major trunk,
buccal nerve arises from both divisions, minor trunk joins
lower division.
ii). Type VB
upper division from major & lower from minor
trunk, buccal nerve arises from both division.
iii). Type VC
upper & lower division both arise from the major
trunk & minor trunk enters the upper division as a separate
branch.

77. Variation of Marginal Mandibular branch
I)
The MMB showed one (28%), two (52%), three
(18%), or four branches (2%) where it exited the
parotid gland.
II)
Type I (60%)
did not communicate with other branches.
Type II (40%)
communicated with the buccal or cervical
branches, or with another branch of the MMB
III)
The MMB pass the facial artery superficially (42%),
deeply in 4%, and on both sides of it in 54% of the
facial halves

79. Age Changes
Child
Adult
Chorda tympani may exit
through Stylomastoid Foramen
Chorda tympani exit proximal to
Stylomastoid Foramen
2nd genu is more acute and
lateral
2nd genu is less acute and
medial
Nerve trunk is more anterior
and lateral on exit through
Stylomastoid Foramen
Nerve trunk is less anterior and
deeper
Nerve very superficial over
angle of mandible
Nerve less superficial over
angle of mandible

80. Testing of Facial Nerve Branches
 Testing the temporal branches of the facial nerve
To test the function of the temporal branches of
the facial nerve, a patient is asked to frown and
wrinkle his or her forehead.
 Testing the Zygomatic branches of the facial
nerve
The patient is asked to close their eyes tightly.

81.  Testing the buccal branches of the facial nerve

Puff up cheeks (buccinator)

Smile and show teeth (orbicularis oris)

Tap with finger over each cheek to
detect ease of air expulsion on the
affected side

82.  The marginal mandibular nerve may be
injured during surgery in the neck region,
especially during excision of the
submandibular salivary gland or during
neck dissections.

83. Applied Surgical anatomy of
Facial Nerve in
Oral & Maxillofacial Surgery
 Damage to facial nerve is possible in severe
maxillofacial surgeries with basilar skull fractures
anywhere in the area of course of the nerve and would
result in ipsilateral paralysis of the muscles of facial
expression
 Of concern to the surgeon is the close proximity of
the main trunk of facial nerve where it exits the
stylomastoid foramen and mandibular condyle

85.  After exiting the stylomastoid foramen, which is
situated posterolateral to stylomastoid process, the
nerve enters the substance of parotid gland where it
divides into its upper and lower divisions just posterior
to the mandible
 The approximate distance from the lowest pointof the
external bony auditory meatus to the bifurcation of the
facial nerve is 2.3 cm
 Posterior to the parotid gland,the nerve is atleast
2cm deep into the skin surface,from this point the two
branches curve around the posterior mandible,where
they form plexus between the parotid gland and the
masseter muscle

86.  The terminal branches of facial nerve then spread
in a fan like fashion as five separate nerves
 Temporal branch :
It exits the parotid gland anterior to superficial
temporal artery
During an open approach to the TMJ, violation
of this branch is possible

87.  Zygomatic Branch :
Its course is antero superior crossing the zygomatic
bone
Inadvertent damage may occur to this nerve during
open reduction of zygomatic arch or with the use of a
byrd screw or zygomatic hook during closed
approaches
 Buccal Branch:
It runs almost horizontally and will often divide into
separate branch above and below parotid duct as it runs
anteriorly
Injury is possible in association with soft tissue trauma
to the cheek region

88.  Marginal mandibular branch:
It extends anteriorly and inferiorly within the substance
of parotid gland, there may be two or three branches of
this nerve.
These branches run anteriorly parallel to inferior
border of mandible and in some cases the course of the
nerve is above the inferior border.
In essentially all cases the nerve is located above the
inferior border of mandible beyond the facial artery.

89. The marginal mandibular branch is an important
structure encountered at the inferior border of the
mandible just beneath the platysma muscle fibres
during an open approach to the mandibular angle
and body area.
For this reason, an initial incision made
approximately 1 to 1.5cm below the inferior
border which prevents direct exposure or trauma
to the nerve

90.  Cervical Branch:
The cervical branch exits the parotid gland
above its inferior pole and runs downwards
underneath the platysma muscle

91.  The surgeon must be mindful of the facial nerves
intimate involvement with the TMJ, specially when
performing surgical approaches to the joint.
 The temporal and zygomatic branches are at
increased risk during pre auricular approach and the
marginal mandibular branch during submandibular
approach
 The intra oral approach to the TMJ has minimal risk
to the branches of facial nerve which is its major
advantage

92. Complications of parotid surgery
 Intra-operative or post-operative
 Post-operative complications can be classified as
early and late (or long-term) complications.

93. Intra-operative complications of parotid gland surgery
 Intra-operative complications of parotid gland surgery
comprise transection of the facial nerve or one of its
branches, rupture of the capsule of a parotid tumour or
incomplete surgical resection thereof.
 The surgeon has to immediately recognize an intraoperative complication and management thereof must be
performed without delay.
 In the event of nerve injury, immediate nerve repair is
mandatory. Once the segments have been fully mobilized
and brought together without tension, the two ends should
be sutured together.

94.  The nerves are gently grasped with a Bishop forceps.
With an 8-0 nylon suture and a GS-8 needle, the
epineurium is grasped at one end and then sutured to
the other, avoiding deep cuts in the perineurium
 Three sutures are usually adequate to maintain the
anastomosis
 As an alternative to sutures, the surgeon may use
fibrin tissue adhesive.
 If the nerve length is inadequate, a nerve graft of the
greater auricular nerve, can be applied

95. Post-operative complications of
parotid gland surgery
Post-operative facial nerve dysfunction involving some
or all of the branches of the nerve is the most frequent
early complication of parotid gland surgery.
Temporary facial nerve paresis, involving all or just one or
two branches of the facial nerve, and permanent total
paralysis have occurred.
The cases of transient facial nerve paresis generally
resolved within 6 months

96. The incidence of facial nerve paralysis is higher with
total, than with superficial parotidectomy, which may be
related to stretch injury or as result of surgical
interference with the vasa nervorum
The branch of the facial nerve most at risk for injury
during parotidectomy is the marginal mandibular
branch.
Older patients appear to be more susceptible to facial
nerve injury

97.  However, eye protection must be ensured. If facial
paresis causes incomplete closure of the eye, the patient
must be advised to use ophthalmic moisture drops
frequently during the day and an ophthalmic ointment
and eye protection at night.
 Regular follow-up with an ophthalmologist is mandatory
 Moreover, use of botulinum toxin to induce temporary
ptosis avoids the need of surgical tarsorrhaphy.

99. Identification of Facial Nerve
3 surgical maneuvers used to identify nerve trunk
A. Blood free plane in front of external acoustic
meatus
B. Exposure of anterior border of SCM below
insertion into mastoid process
C. Peripheral identification of terminal branch of
facial nerve (marginal mandibular branch)

101. Disorders of Facial Nerve
Facial Nerve Lesions
1. Supra nuclear type:
Features:
a)
b)
c)
d)
Paralysis of lower part of face (opposite side)
Partial paralysis of upper part of face
Normal taste and saliva secretion
Stapedius not paralysed

105. 2. Nuclear type:
Features:
a) Paralysis of facial muscle (same side)
b) Paralysis of lateral rectus
c) Internal strabismus

106. 3. Peripheral lesion
a) At internal acoustic meatus
Features:
i.
ii.
iii.
iv.
v.
Paralysis of secretomotor fibers
Hyper acusis
Loss of corneal reflex
Taste fibers unaffected
Facial expression and movements paralysed

107. Lesion at int
acoustic meatus

108. b) Injury distal to geniculate ganglion
Features:
i.
ii.
iii.
iv.
v.
vi.
Complete motor paralysis (same side)
No hyper acusis
Loss of corneal reflex
Taste fibers affected
Facial expression and movements paralysed
Pronounced reaction of degeneration

109. Lesion
distal to
geniculate
ganglion

110. c) Injury at stylomastoid foramen
•
Condition known as Bell’s Palsy

111. Background of BELL’S PALSY
First described more than a
century ago by Sir Charles Bell
Yet much controversy still
surrounds its etiology and
management
.
Bell palsy is certainly the most
common cause of facial paralysis
worldwide

112. Demographics of Bells palsy
Race: slightly higher in persons of Japanese descent.
Sex: No difference exists
Age: highest in persons aged 15-45 years.
Bell palsy is less common in those younger than 15 years
and in those older than 60 years.

113. Pathophysiology of Bells palsy
Main cause of Bell's palsy is latent herpes viruses
(herpes simplex virus type 1 and herpes zoster virus),
which are reactivated from cranial nerve ganglia
Polymerase chain reaction techniques have isolated
herpes virus DNA from the facial nerve during acute
palsy

114. Inflammation of the nerve initially results in a
reversible neurapraxia
Herpes zoster virus shows more aggressive
biological behaviour than herpes simplex virus
type1
Bell's phenomenon is the upward diversion of
the eye ball on attempted closure of the lid is seen
when eye closure is incomplete.

115. Features of Bell’s Palsy
I.
Unilateral involvement
II.
Inability to smile, close eye or raise eyebrow
III. Whistling impossible
IV. Drooping of corner of the mouth
V. Inability to close eyelid (Bell’s sign)
VI. Inability to wrinkle forehead
VII. Loss of blinking reflex
VIII.Slurred speech
IX. Mask like appearance of face
X. Loss/ alteration of taste

116. Fore head

117. Diagnosis of Bells palsy
By exclusion
Criteria
Paralysis or paresis of all muscle groups of one side of
the face
Sudden onset
Absence of signs of CNS disease
Absence of signs of Ear disease

118. Management of Bells palsy
Eye care
It focuses on protecting the cornea from drying and
abrasion due to problems with lid closure and the
tearing mechanism.
Lubricating drops should be applied hourly during
the day and a simple eye ointment should be used at
night.

119. Treatment consists of Infra-red radiation on affected
side of the face at 2 ft (60cm) ,followed by interrupted
galvanism on affected side
Treatment was given daily at first few weeks & later
thrice weekly.
All patients are instructed to massage the face daily
There is general agreement that 70-80% of these
patients recover completely,while the reminder develop
various sequelae within one to three months

120. Medical treatment
Corticosteroids :
Prednisolone 1 mg/kg/day 7-10 days
Corticosteroids combine with antiviral drug is better
Acyclovir 400 mg 5 times/day
Famciclovir and valacyclovir 500 mg bid

121. Surgical treatment
Facial nerve decompression
Indication:
Completely paralysis
ENoG less than 10% in 2 weeks
Appropriate time for surgery is 2-3 weeks after paralysis

122. Causes of Facial Nerve Paralysis

Peripheral nerve causes (Facial muscle paralysis with
forehead affected)
 Lyme Disease
 Otits Media or Mastoiditis
 Ramsay Hunt Syndrome
 Autoimmune Polyneuropathy (e.g. Guillain-Barre Syndrome,
typically bilateral)
 Head or Neck Mass Lesion (e.g. Cholesteatoma)

123.  Central/Supranuclear causes
(Facial muscle paralysis with forehead spared)
 Cerebral mass lesion (e.g. tumor)
 Cerebrovascular Accident (typically with ipsilateral
Hemiparesis or Hemiplegia)
 Multiple Sclerosis

124. Traumatic causes
 Cortical injury
 Temporal BoneFracture
 Brain Stem injury
 Penetrating middle ear injury
 Barotrauma
Altitude paralysis
Scuba Diving

125. Endocrine causes
 Diabetes Mellitus
 Hyperthyroidism
 Pregnancy
 Hypertension
 Alcohol Abuse (Alcoholic Neuropathy)

126. Infectious Causes

Malignant Otitis Externa (skull base Osteomyelitis)

Acute or Chronic Otitis Media
Gradenigo's Syndrome (CN V or CN VI)

Mastoiditis

Varicella Zoster Virus (Chicken Pox)

Herpes Zoster Oticus (Ramsey-Hunt Syndrome)
Herpetic Vesicles at auricle and external canal

127.  HIV Infection
 Influenza Vaccine and Influenza
 Parotitis
 Meningitis or Encephalitis
 Mumps
 Mononucleosis

128.  Leprosy
 Coxsackie virus infection
 Syphilis
 Tuberculosis
 Botulism
 Mucormycosis

129. Causes due toTumors
 Facial Nerve neuroma
 Cholesteatoma
 Glomus jugular tumor
 Primary Temporal Bone tumors
 Meningiomas
 Hemangioblastoma
 Hemangioma
 Pontine glioma
 Parotid tumor

130. A tumor compressing the facial nerve result
in Facial paralysis

131. Birth Causes

Facial Nerve Injury from Birth Trauma

Trauma (forceps delivery)

Congenital Facial Palsy
Mobius syndrome
Cardiofacial syndrome

132. Toxic Causes:

Thalidomide

Tetanus

Diphtheria

Carbon Monoxide

Lead Intoxication

133. Idiopathic Causes:

Myasthenia Gravis

Guillain-Barre Syndrome

Sarcoidosis

Familial Bell's Palsy

134. Iatrogenic Causes:

Antitetanus serum

Vaccine treatment for Rabies

Mandibular block anesthesia

Head and neck surgery

135. Evaluation of Facial paralysis
Clinical feature
Central VS Peripheral facial paralysis
Complete head and neck examination
Cranial nerve evaluation
Electrodiagnostic testing
Topographic diagnosis

136. Central facial paralysis
Upper motor neuron lesion
Movements of the frontal and upper orbicularis oculi tend to be
spared
Because of uncrossed contributions from ipsilateral
supranuclear areas
Involvement of tongue
Involvement of lacrimation and salivation

137. Peripheral paralysis
Lower motor neuron lesion
At rest :
less prominent wrinkles on forehead of affected side, eyebrow
drop, flattened nasolabial fold, corner of mouth turned down
Unable to :
wrinkle forehead, raise eyebrow, wrinkle nasolabial fold,
purse lips, show teeth, or completely close eye

139. House-Brackmann grading system
Grade I - Normal
Grade II - Mild dysfunction, slight weakness on close
inspection, normal symmetry at rest
Grade III - Moderate dysfunction, obvious but not disfiguring
difference between sides, eye can be completely closed with
effort
Grade IV - Moderately severe, normal tone at rest, obvious
weakness or asymmetry with movement, incomplete closure of
eye
Grade V - Severe dysfunction, only barely perceptible motion,
asymmetry at rest
Grade VI - No movement

140. Testing of Facial Nerve
TOPOGNOSTIC TESTING
1.
2.
3.
4.
Schirmer test for lacrimation (GSPN)
Stapedial reflex test (Stapedial branch)
Taste testing (Chorda tympani nerve)
Salivary flow rates & pH (Chorda tympani)
ELECTROPHYSIOLOGIC TESTS
Nerve excitability test (NET)
Electromyography(EMG)
Maximal stimulation test (MST)
Electroneuronography (ENoG)
DYES

141. Topographic Diagnosis
To determine the anatomical level of a peripheral lesion
Lacrimation
Stapedius reflex
Taste
Geniculate ganglion
motor nerve of stapedius muscle
chorda tympani

142. Schirmer's Test
Geniculate ganglion & petrosal nerve function test
Schirmer’s test +ve when
Affected side shows less than half the amount of lacrimation
seen on the normal side
Sum of the lengths of wetted filter paper for both eyes less
than 25 mm
Lesion at or proximal to the geniculate ganglion

143. Schirmer's Test

144. Stapedius reflex
Nerve to stapedius muscle test
Impedence audiometry can record the presence or
absence of stapedius muscle contraction to sound
stimuli 70 to 100 db above hearing threshold
An absence reflex or a reflex less than half the
amplitude is due to a lesion proximal to stapedius
nerve

145. Taste (Electrogustometry)
Chorda tympani nerve test
Solution of salt, sugar, citrate, quinine or Electrical
stimulation
Compares amount of current require for a response each
side of tongue
Normal : difference < 20 uAmp (thresholds differening by
more than 25%= abnormal)
Total lack of Chorda tympani : No response at 300 uAmp
Disadvantage : False +ve in acute phase of Bell’s palsy

146. Maximum stimulation Test: MST:
Indication: complete paralysis<3wks
Interpretation:
Marked weakness or no muscle contraction:
advanced degeneration with guarded prognosis

147. Electroneurography: ENoG
Indication: complete paralysis<3wks
Interpretation: < 90% degeneration: prognosis is
good; > or = 90%: prognosis is a question
Limitation: False-positive results in deblocking phase.

149. Electromyography: EMG
Indication: Acute paralysis less than 1 week or chronic
paralysis longer than 2 weeks
Interpretation:
Active mu: intact motor axons
Mu + fibrillation potentials: partial degeneration
Polyphasic mu: regenerating nerve
Limitation: cannot assess degree of degeneration or
prognosis for recovery

150. Herpes zoster oticus
Ramsay Hunt syndrome type II
Symptoms:
 Facial paralysis
 Ear pain
 Vesicles
 Sensorineural
hearing loss
 Vertigo

151. Acute and chronic otitis media
Otitis media is an infection in the middle ear, which can
spread to the facial nerve and inflame it, causing
compression of the nerve in its canal.

152. Neurosarcoidosis
Facial nerve paralysis, sometimes bilateral, is a
common manifestation of neurosarcoidosis
(sarcoidosis of the nervous system)..
Itself a rare condition.

153. Congenital Facial nerve palsy
Moebius syndrome (congenital facial diplegia)
 Abnormal VI ,VII,XII Nerve nuclei
 Facial Nerve absent / smaller
 Congenital Extra ocular muscle & facial palsy

154. Cardiofacial Syndrome
Unilateral facial paralysis involving only the lower lip
and congenital heart disease
 The facial paralysis in these patients involves only
those muscles concerned with pulling the lower
lip downwards and outwards
 These are the
mentalis, depressor labii inferioris and depressor
anguli oris muscles

155. All are supplied by the mandibular marginal branch of
the facial nerve.
Lesions of this nerve have been recognized in adults
and children for many years
The paralysis is only recognizable when the patient
talks, smiles or cries

156. Treacher collins syndrome
(mandibulo facial dysostosis)
There is a set of typical symptoms within Treacher Collins
Syndrome
The OMENS classification was developed as a
comprehensive and stage-based approach to differentiate
the diseases.
O; orbital asymmetry
M; mandibular hypoplasia
E; auricular deformity
N; nerve development and
S; soft-tissue disease

157. Facial Nerve involvement in
Treacher collins syndrome
N0: No facial nerve involvement
N1: Upper facial nerve involvement (temporal or
zygomatic branches)
N2: Lower facial nerve involvement (buccal,
mandibular or cervical)
N3: All branches affected

158. Goldenhars syndrome
(oculoauriculo vertebral dysplasia)
It is a wide spectrum of congenital anomalies that
involves structures arising from the first and second
branchial arches.
Features of hemi facial microsomia, anotia, vertebral
anomalies, congenital facial nerve palsy.

159. Conclusion
Surgeons have to pay attention to minimize the risk of
complication during parotidectomy.
The best means of reducing iatrogenic facial nerve injury, in
parotid surgery, still remains a clear understanding of the
anatomy, good surgical technique with the use of multiple
anatomic landmarks.
Pre-operative discussion and consent for surgery, tailored
according to the age and health of the patient as well as the
behavior of the tumor, are mandatory
Furthermore, the patient has to be informed about the
cosmetic sequelae of the incision and all patients have to be
told that facial nerve paralysis or paresis is possible and can
be partial or total, temporary or permanent.

160. References
Fonseca & Walker : Maxillo FacialTrauma 2nd Edition
Vol 1 & 2
Grays Anatomy : 39th Edition
Netters : Colour Atlas of Anatomy
International journal of Oral & maxillofacial Surgery

161. Guided by:
Dr.S.M.Nooruddin MDS.,
Professor & HOD
Dept of Oral & Maxillofacial Surgery
Dr.K.Surekha MDS.,
Associate Professor
Dr.G.Sudhakar MDS.,
Assistant Professor
Presented by:
Dr.T.Roger paul
1st yr PG
GDC&H,
VIJAYAWADA.

162. THANK YOU