The facial nerve emerges from the brainstem and controls facial muscle expression. It has motor, sensory and parasympathetic components. The nerve passes through the facial canal and has multiple branches that innervate muscles of the face. Damage to the nerve can occur at various points along its course and results in facial paralysis. Bell's palsy is the most common cause of acute facial paralysis and results from inflammation of the nerve as it exits the skull.

1. Facial Nerve

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

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.  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
Introduction

5. Embryology

7. end of the 5th week Facial motor nucleus, nervus intermedius and greater
superficial petrsoal nerve
6th Week posterior auricular branch, branch of digastric
Early 7th week geniculate ganglion is well-defined
Early 8th week temporofacial and cervicofacial divisions present
Late 8th week 5 major peripheral subdivisions present

8. Course of facial nerve…………….

10. Facial nucleus
Abducens nucleus
Superior salivatory nucleus –
parasympathetic
Tractus solitaries
Spinal nucleus of trigeminal nerve
?

11. Functional Components …..

13. Anterior WallPost Wall

15. Facial
nerve
Temporofacial
Cervicofacial
2.Zygomatic
3.Buccal
4.Marginal mandibular
5.Cervical
1.Tempor
al
1
2
3
4
5

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

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

18. GANGLIAASSOCIATED…….
Geniculate ganglion
Submandibular ganglion
Pterygopalatine ganglion

19. Geniculate Ganglion
located-first bend of the facial nerve,in relation to
the medial wall of the middle ear
the taste fibres present in the nerve-peripheral
processes of psuedounipolar neurons present in
the geniculate ganglion
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.

20. Submandibular Ganglion
• lies in the hyoglossus muscle just above the
deep part of the submandibular salivary gland
• Parasympathetic peripheral ganglion
• Relays secretomotor fibres to the submandibular
and sublingual glands
• Functionally - facial nerve(chorda tympani)
• Topographically-lingual nerve

21. Pterygopalatine Ganglion
Largest parasympathtic peripheral ganglion
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

22. Facial Nerve blood supply
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
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

23.  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
Applied Surgical anatomy of Facial Nerve in
Oral & Maxillofacial Surgery

24. Surgical landmarks for identifying location of main
trunk of the facial nerve and the temporal-facial
division during temporomandibular joint arlhroplastic
dissection.
Note the variability at the point where the upper trunk
of the facial
- nerve crosses the zygomatic trunk deep to the
temporoparietal fascia. The nerve can cross point from 8
to 35 mm anterior lo the bony auditory canal.
Consequently, the plane of dissection must be deep to
the temporoparietal fascia as the tissues are retracted
anteriorly to gain access to the joint capsule.

25. Note that the inferior extent of the incision is the soft tissue attachment of the lobule of the ear and also
that the superior arm of the incision can be extended into the temporal hairline at a 45-degree angle if
greater anterior retraction of the surgical flap is necessary.

26. Locating the frontal branch
The line of Pitanguy

27. • SMAS is a fibromuscular layer,seperated from underlying parotid
fascia but is continous inferiorly with platysma
• SMAS invests sup mimetic muscles below zyg arch,as
temporaparietal fascia invests frontalis muscles above the arch.
• VII nerve runs deep to platysma and smas
• Refernce anatomical plane
SMAS

29. The mean horizontal distance of the zygomatic branch from
the midpoint between the tragus and the lateral palpebral
commissure was 2.5 cm.
Cutaneos reference point for zygomatic branch
Sur Radiol Anat
Skin reference point for the zygomatic branch of the facial nerve
innervating the orbicularis oculi
A.Chatellier et l.
2012

30. Buccal
Buccal branch mainly consisted of 2-3 ramifications in 87.5% of the specimens, while marginal mandibular
branch was double or single in 95.9% of the specimens. The buccal branch coursed within the distance
between 10.7 mm above and 9.3 mm below the parotid duct, and innervated mimetic muscles of midface.
The marginal mandibular branch coursed within the distance between 13.4 mm above and 4.8 mm below
the lower border of mandible, crossed superiorly the facial artery and innervated mimetic muscles of lower
lip.
Zhonghua Zheng Xing Wai Ke Za Zhi. 2007
Sep;23(5):434-7.
[Anatomy of buccal and marginal mandibular
branches of facial nerve and its clinical significance].
[Article in Chinese]
Liu AT1, Jiang H, Zhao YZ, Yu DZ, Dang RS, Zhang
YF, Zhang JL.

31. Locating the Marginal Mandibular Branch
The branch of the facial nerve most at risk for injury during
parotidectomy is the marginal mandibular branch.
the facial artery can be used as an important landmark in locating the marginal mandibular nerve during surgical
procedures

32. Cervical Branch
Plast Reconstr Surg. 2010 Sep;126(3):875-9. doi: 10.1097/PRS.0b013e3181e3b374.
Locating the cervical motor branch of the facial nerve: anatomy and clinical application.
Chowdhry S1, Yoder EM, Cooperman RD, Yoder VR, Wilhelmi BJ.
Schematic drawing of the location of the
branching point of the cervical motor
branch of the facial nerve. Notice the
mastoid-mentum line and the
perpendicular line about the angle of the
mandible to aid in locating the branching
point.
located at approximately 1 cm below a
perpendicular line
from the angle of the mandible to a line
drawn
from the mentum to the mastoid process
with the neck extended and the head turned
to the contralateral
side.

33. Surgical Land Marks to identify facial nerve during Parotid Surgery
1. The posterior belly of digastric muscle (PBDM)
2. The tragal pointer (TP)
3. The junction between the bony and cartilaginous
external auditory meatus (EAM)
4. Tympanomastoid suture (TMS)
Paul M. Rea, Gerry McGarry, John Shaw-Dunn, The precision of four commonly used surgical
landmarks for locating the facial nerve in anterograde parotidectomy in humans, Annals of
Anatomy - Anatomischer Anzeiger, Volume 192, Issue 1, 20 February 2010, Pages 27-32

34. shortest distance between main trunk of the facial nerve
and the tragal pointer (TP)/ conley’s point
6.91.8mm
•As the tragal cartilage is dissected free from the parotid fascia, it takes
pointed shape in its medial aspect, which is called the “pointer”.
•It is regarded as the most important landmark.

35. Shortest distance between main trunk of the facial
nerve and the posterior belly of digastricmuscle
(PBDM)
5.5  2.1mm

36. shortest distance between main trunk of the facial
nerve and the tympanomastoid suture (TMS)
2.50.4 mm

37. shortest distance between main trunk of the facial nerve and
the junction between the bony and cartilaginous auditory canal
(EAM); VII=facial nerve, MP=mastoid process,
10.91.7mm

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

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

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

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

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

43. 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

44. 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.

45. 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
Other hypothesis of etiology :
I. Rheumatic hypothesis
II. Cold hypothesis
III. Ischemic hypothesis
IV. Immunological hypothesis
V. Trauma

46. Bell's phenomenon is the upward diversion of the eye
ball on attempted closure of the lid and inability to
close the .

47. 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
Features of Bell’s Palsy

48. 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

49. Diagnosis of Bells palsy
In 1959 , Travener outlined the minimum diagnostic criteria for
bells palsy
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

50. Management of Bells palsy
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.
Eye care

51. 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

52. Sit relaxed in
front of a
mirror.
Gently raise
eyebrows, you can
help the movement
with your fingers.
Draw your
eyebrows
together, frown.
Wrinkle up your
nose.
Hold pencil or
lollipop stick
between lips.
Curl up top lip. Turn down bottom Blow out cheeks.
Physiotherapy

53. Corticosteroid is the best treatment
Combination of predinisone & acyclovir
1mg/kg body wt predinisone & Acyclovir200-400mg orally 5
times
Fagan recommended following regimen of prednisone
60mg x 3days
40mg x 3days
20mg x 3 days
10mg x 3 days
5 mg x 3 days
Management (medical)

54. Surgical treatment
Facial nerve decompression
Indication:
Completely paralysis
Appropriate time for surgery is 2-3 weeks after paralysis

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

56. 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.

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

58. 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

59. 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

60. 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

61. 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

62. 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.

63. • To determine site of facial nerve injury
• Relies on knowledge of facial nerve branches
Testing of facial nerve function

64. Branches:
• Greater superficial petrosal nerve:
–Lacrimation
Test: Schirmer test
• Wetting reduced to less than 25%- positive
• Indicates site of lesion –above the geniculate
ganglion
Testing of facial nerve function

65. •Nerve to stapedius:
–Stapedius reflex
Test: Audiometrical evaluation
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

66. •Chorda tympani nerve:
–Taste
Test: Testing taste
–applying galvanic current &noting a metallic taste on the
normal side of the tongue &sensation of electric shock on the
affected side.

67. Testing of Peripheral Branches of Facial Nerve
 Testing the temporal branches of the facial nerve
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.

68.  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

69. pulling the lower lip downwards and outwards
 Testing the marginal mandibular branche of the facial
nerve

70.  Testing the cervical branches of the facial nerve
Contract the platysma.

71. Conclusion
Surgery of the face is not for the occasional operator. A precise
knowledge of the course of the facial nerve and its branches in
relation to anatomical landmarks is required. No less important is
an understanding of their relationship to the fascial planes of the
head and neck.

72. 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