divya jain

1. 1

2. DR DIVYA JAIN
1st YEAR POSTGRADUATE STUDENT
INNERVATION OF
MAXILLOFACIAL STRUCTURES
2

3. Content
• Introduction
• Basics Of Nervous System
• Cranial Nerves
o Olfactory Nerve
o Optic Nerve
o Oculomotor Nerve
o Trochlear Nerve
o Trigeminal Nerve
o Abducent Nerve
3

4. o Facial Nerve
o Vestibulocochlear Nerve
o Glossopharyngeal Nerve
o Vagus Nerve
o Accessory Nerve
o Hypoglossal Nerve
• Secretomotor Fibres
o Parotid Gland
o Submandibular Gland
o Sublingual Gland
• Significance In Prosthodontics
• References
4

5. • The peripheral nervous system (PNS) is that portion of the
nervous system outside the central nervous system.
• The PNS conveys impulses to and from the brain and spinal
cord.
• Sensory receptors within the sensory organs, nerves, ganglia,
and plexuses are all part of the PNS, which serves virtually
every part of the body.
5
Introduction

6. 6
•Sensory nerves consists of sensory (afferent) neurons that
convey impulses toward the CNS.
• Motor nerves consist primarily of motor (efferent) neurons
that convey impulses away from the CNS. (Technically speaking,
there are no nerves that are motor only; all motor nerves contain
some proprioceptor fibers that convey sensory information to the
CNS.)
• Mixed nerves are composed of both sensory and motor
neurons in about equal numbers, and they convey impulses both to
and from the CNS

7. Basics Of Nervous System
7

8. 1. Afferent : sensory input
2. Efferent : motor output
3. Somatic : to skeletal muscles
4. Visceral : to smooth muscles , cardiac muscles and glands
5. Special : refers to functional components that are carried by
cranial nerves only.
TERMINOLOGIES
8

9. Neuron , Nucleus , Ganglion
 Neuron :- This is defined as the basic structural and
functional unit of nervous system.
Nucleus :- These are nothing but the cluster of neurons
present in CNS, which consist of brain and spinal
cord.
Ganglion :- These are cluster of neurons present in the
PNS.
9

10. • Neuron
10
Source: Internet

11. Neurons can be classified according to the
number and arrangement of this processes:
• Multipolar : extensive dendrite tree like and the most common
• Bipolar : arise from a single dendrite and functions both sides
• Unipolar : have a single short process and has a single pathway.
11

12. 12
 Vertebrates have three types of neurons :-
1. SENSORY NEURONS to CNS ( AFFERENT NEURONS )
Types of Neurons

13. MOTOR NEURONS (EFFERENT NEURON) to effectors (
muscles and glands )
 INTERNEURONS (ASSOCIATION NEURONS) provide
associative function.
13

14. Gray’s anatomy of human body; Richard L.Drake, A.waynevoge,Adam W.M.mitchele:2nd edition
14

15. CRANIAL NERVES
15

16. There are 12 pairs of cranial nerves emerging from the
brain and radiating from its surface.
They pass through skull foramina, fissures or canals to
exit the cranial vault and distributes their innervation to
their respective structures in the head and neck.
In addition, the cranial nerves are numbered sequentially
with roman numerals in the order in which they arise
from the brain, rostrally to caudally.
16

17. 17
Source: Internet

18. Cranial nerves are as follow:
• Sensory -I, II, IX
• Motor – III, IV, VI, XII
• Both(mixed) -V, VII, VIII, X, XI
• Some Say Money Matter But My Big Brother
Says Big Brain Matter
18

19. Cranial nerve-I
Olfactory Nerve (Sensory)
19
Human anatomy;kent-van-de-graff:6th edition;2001

20. The olfactory nerve (I) is attached to the
under surface of the frontal lobe; its
connections pass to the temporal lobe
and elsewhere.
Leaves the cranial cavity through
cribriform plate.
Location of cell bodies:Bipolar cells in
nasal mucosa
Function –olfaction
20

21. 21
Clinically:
Bilateral anosmia & CSF leak are common signs of
head injuries with anterior cranial fossa fracture.
Examination
Patient asked to differentiate odors (tobacco, coffee, soap, etc.) with
eyes closed.
Comment
Nasal passages must be patent and tested separately by occluding
the opposite side.

22. 22
Cranial nerve-II
Optic Nerve (Sensory)

23. • Leaves the cranial cavity
through the optic canal They
join each other to form the
chiasma.
• Location of cell bodies:
Ganglion cells of retina
• Function : vision
Optic (Sensory)
23

24. 24
Clinically:
• Section through the optic nerve causes epsilateral blindness.
• Lesions behind the optic chiasma (pituitary gland tumors) lead to
contro-lateral blindness.
Examination
Retina examined with ophthalmoscope; visual acuity tested with
eye charts.
Comment
Visual acuity must be determined with lenses on, if patient wears
them

25. 25
Cranial nerve-III
Oculomotor nerve: (Motor)

26. 26
•Origin: Midbrain
• Cranial passage: superior orbital fissure
• Innervates :
- Extra-occular muscles :
1.)Superior, Inferior & Medial Recti Muscles
2.)Inferior oblique Muscle
-Also levator palpabre superioris
• Causes the eye to turn upward, downward and
medially.

27. 27
Edinger-Westphal Nucleus
• Source of the parasympathetics to the eye, which constrict the pupil
and accommodate the lens.
• It is located just inside the oculomotor nuclei.
• The fibers travel in the IIIrd nerve, so damage to that
nerve will also produce a dilated pupil.

28. • Examination
Patient follows examiner’s finger movement with eyes—
especially movement that causes eyes to cross; pupillary change
observed by shining light into each eye separately
Comment
Examiner should note rate of pupillary change and coordinated
constriction of pupils. Light in one eye should cause a similar
pupillary change in other eye, but to a lesser degree.
Clinically:
• Inability to look up, down or medially.
• Dilatation of the pupil.
• Ptosis (drooping of the eyelid paralysis of levator palpebrae
superioris) 28

29. Cranial nerve –IV
Trochlear nerve: (motor)
29

30. • It’s the smallest cranial nerve
• Trochlear nerve is so called because superior oblique (which it
supplies) is arranged as a pulley (Latin: trochlea – pulley).
• Somatic efferent nerve
• Foramen:superior orbital fissure
• Location of cell bodies: trochlear nucleus
• Function : Motor impulses to superior oblique muscle of
eyeball.
Proprioception from superior oblique muscle of eyeball
30

31. Examination
Patient follows examiner’s finger movement with eyes
especially lateral and downward movement
Clinically:
•Unable to look downward and inward
•Difficulty in walking downstairs
31

32. 32
Cranial nerve-V
Trigeminal Nerve(mixed)

33. Trigeminal Nerve
33
Anterior Aspect Of Pons
( Sensory And Motor Root )
Middle Cranial Fossa
Meckel’s cavity ( Trigeminal Ganglion)
Ist Division
Ophthalmic
Superior orbital
fissure
IInd Division
Maxillary
Foramen Rotundum
IIIrd Division
Mandibular
Foramen Ovale

34. MOTOR ROOT
• It unites with the sensory root and forms a single nerve
trunk.
• It supplies the following muscles:
1. Muscles of mastication
2. Mylohyoid
3. Anterior belly of the diagastric
4. Tensor tympani
5. Tensor veli palatini
34

35. SENSORY ROOT
•The fibres of the sensory root arise from the cells of the
trigeminal ganglion.
• The peripheral branches are grouped to form the ophthalmic
and maxillary nerves and sensory part of the mandibular nerve.
35

36. Various nuclei associated with the fifth nerve are situated within the
pons. They are:
1. Motor nucleus- to muscles of mastication
2. Sensory nucleus- represents touch/position sensation
from the face
3. Mesencephalic nucleus- proprioception.
4. Proprioception of the face is the feeling of relative
position of the muscles.
5. Spinal nucleus- pain and temperature sensation.
36

37. Ophthalmic Nerve
Trigeminal Ganglion
Middle Cranial Fossa
Lateral wall of Cavernous Sinus
Superior Orbital Fissure
Orbit
37
Lacrimal,Frontal and Nasociliary

38. Lacrimal Nerve
Superior Orbital Fissure
Lateral wall of Orbit
Above the Lateral Rectus muscle
Lacrimal Gland
38
Supplies the lacrimal gland, the conjunctiva
and upper eyelid

39. Frontal nerve
39
Superior Orbital Fissure
Levator Palpebrae Superioris
Rim of Orbit
Supra-orbital Supra-trochlear
It supplies the skin of the forehead ,
conjunctiva,central part of upper of
eyelid,frontal air sinus and skin of
forehead above the root nose and scalp.
It supplies the conjunctiva , the
upper eyelid & lower part of
the forehead.

40. Nasociliary Nerve
Superior Orbital Fissure
Within common tendinous ring of Recti
Optic Nerve
Below superior rectus & superior oblique
Medial orbital wall
40
Anterior Ethmoidal
Posterior
Ethmoidal
Long
Ciliary
Infra-trochlear
External nasal Internal nasal

41. i. A communicating branch to ciliary ganglion
ii. Long ciliary nerve: Supplies the Iris & Cornea.
iii. Posterior ethmoidal nerve: supplies to the ethmoidal and
sphenoidal air sinus.
iv. Infratrochlear nerve- supplies the conjunctiva, the lacrimal sac,
medial end of eyelids and upper half of external nose
41

42. 42
MAXILLARY NERVE
Gasserion Ganglion
Foramen Rotundum
Pterygopalatine Fossa
Infra –Orbital Canal
Infra –Orbital Foramen
Face Nerve
Inferior palpebral
External nasal
Superior labial
Middle Meningeal N.
Pterygopalatine N
Posterior superior
alveolar N
Zygomatic N
Anterior superior alveolar N
Middle superior alveolar N

43. 43
Within Pterygopalatine Fossa
Zygomatic N
Inferior Orbital Fissure
Zygomaticotemporal
Skin of temple
Zygomaticofacial
Facial prominence of
cheek
Posterior superior Alveolar N. - Maxillary molars , buccal mucosa
in molar region

44. 44
Continued….Pterygopalatine Nerves
Orbital
Nasal Palatine
Greater
Palatine N.
Middle
Palatine N.
Posterior
Palatine N.
Posterior Hard
Palate
Soft palate
Soft palate,
Tonsil,uvula
Periosteum of orbit
and orbitalis
muscle
Nasopalatine N Medial
posterior
superior
nerve
Lateral
posterior
superior
nerve
Anterior part of
Hard palate Superior and
middle conchae
Posterior part of roof of
nose and nasal septum
Pharyngeal
Part of nasopharynx

45. 45
Maxillary Nerve Branches
( Within Infraorbital Canal )
Anterior superior alveolar nerve
Maxillary Incisors, canine
Middle superior alveolar nerve
Maxillary premolars

46. 46
Maxillary Nerve Branches ( On The Face )
Inferior Palpebral
branches
External nasal
branches
Superior labial
branches
Lower Eyelid Upper Lip, cheekSide of Nose

47. 47
Sensory Root
MANDIBULAR NERVE
Gasserion Ganglion
Motor root
Nervous spinosus
Foramen Ovale
Main trunk
Nerve to medial
pterygoid
Anterior division
Posterior division
Buccal nerve
Nerve to Masseter
Nerve To Temporalis
Nerve to Lateral
Pterygoid
Auriculo-temporal-
Mylohyoid nerve
Lingual nerve
Inferior alveolar nerve-
Superficial
temporal
Cutaneous
Mental
Incisive

48. 48

49. Branches of the Auriculotemporal nerve:
1. Parotid branches-----secretomotor.
2. Articular branches--- to the TMJ.
3. Auricular branches---to the skin of the helix & tragus
4. Meatal branches----- to external auditory meatus.
5. Terminal branches----Scalp over the temporal region
49

50. Trigeminal Ganglion
It is also called as the gasserian
ganglion or semilunar ganglion.
It is a sensory ganglion.
This ganglion lies a little in front of
preauricular point at a depth of 5cm.
The ganglion lies on trigeminal
impression on the anterior surface of
petrous temporal bone near its apex.
It occupies a space of dura mater
called trigeminal or meckel’s cave.
50

51. 51
Examination :
Motor portion: Temporalis and masseter muscles palpated as patient
patient asked to open mouth against resistance strength applied by
examiner.
Sensory portion: Tactile and pain receptors tested by lightly touching
patient’s entire face with cotton and then with pin stimulus.
Comment :
Muscles of both sides of the jaw should show equal contractile
clenches teeth;
Patient’s eyes should be closed and innervation areas for all three nerves
branching from the trigeminal nerve should be tested.

52. Clinically
Shingles and varicella-zoster
• The trigeminal ganglion, as any sensory ganglion, may be the
site of infection by the herpes zoster virus causing shingles, a
painful vesicular eruption in the sensory distribution of the
nerve.
• The virus may have been latent in the ganglion following
chickenpox (varicella).
Trigeminal neuralgia
• This is severe pain in the distribution of the trigeminal nerve
or one of its branches, the cause often being unknown.
• It may require partial destruction of the ganglion.
52

53. • Fracture midface, zygoma or mandible might lead to
anaesthesia to light touch and other modalities.
• Lesions of the entire nerve leads to anaesthesia and
paralysis and atrophy of the muscles of mastication.
53

54. Trigeminocardiac reflex
• The trigeminocardiac reflex is reflexive response of
bradycardia, hypotension, and gastric hypermotility induced
with mechanical stimulation in the distribution of the
trigeminal nerve.
• It is reflex bradycardia, hypotension, apnea, and increased
gastric motility which may be induced with manipulation or
stimulation of any of the peripheral branches or the central
component of the trigeminal nerve.
54

55. Causes of trigeminocardiac reflex-
• TMJ surgeries- injury to articular branches.
• Le forte 1 osteotomies
• Elevation of zygoma.
1-gasserian ganglion
2-sensory nucleus of
trigeminal nerve
3-internuncial fibre
4-motor nucleus of
vagus nerve
5- vagus nerve
55

56. 56
Cranial nerve-VI
Abducent :(motor)

57. • Origin : fibres originate from the ipsilateral
abducens nuclei located in the caudal pons
beneath the 4th ventricle .
• Somatic, leave the brain through the superior
orbital fissure
• Supply the lateral rectus muscle.
• Location of cell bodies- Abducens nucleus
• Function : Motor impulses to lateral rectus
muscle of eyeball
• Proprioception from lateral rectus muscle of
eyeball 57

58. 58
Examination
Patient follows examiner’s finger movement—especially
lateral movement.
Comment
Motor functioning of cranial nerves III, IV, and VI may be
tested simultaneously through selective movements of
eyeball.
Clinically:
• Strabismus and diplopia on lateral gaze

59. Cranial nerve-VII
Facial Nerve(Mixed)
2
59

60. 60
• 7th cranialnerve
• Mixed nerve- sensory root and motor root
• It emerges from the brain stem between the pons and the
medulla.
• Function- Conveys taste sensation from anterior 2/3rd of
tongue and oral cavity and also , controls the muscles of facial
expression.
• Supplies- preganglionic parasympathetic fibres to several head
and neck ganglia

61. • COURSE AND RELATIONS
Intracranial Course
• Sensory root and motor root.
• Two roots are attached to lower border of pons and medial to
8th nerve.
• Along with 8th nerve the two roots reach internal acoustic
meatus.
• In the meatus ,the motor root lies in a groove on the 8th nerve
,with sensory root intervening .
61

62. • At the bottom of or fundus of the meatus ,the two roots ,sensory
and motor fuse to form a single trunk, which lies in petrous bone.
• Within the canal ,the course of the nerve can be divided in to three
parts by two bends.
• The first part is directed laterally above the vestibule ,the second
part runs back wards in relation to the medial wall of the middle
ear above the promontory.
• Promontory is a rounded bulging produced by the first turn of
cochlea.
62

63. • It is grooved by tympanic plexus.
• The third part is directed vertically downwards behind the
promontory.
Human anatomy; BD chaurasia;CBS Publishers and distributors.pvt ltd;5th edition;vol 3
63

64. • The first bend at the junction of first
and second part is sharp.
• Lies over anterioposterior part of the
promontory ,and is also called as
GENU.
• The geniculate ganglion of the nerve
is so called because it lies on the genu.
• The second bend is gradual ,and lies
between the promontory and the
aditus of mastoid antrum.
• The 7th nerve leaves the skull by
passing through stylomastoid
foramen.
Human anatomy; BD chaurasia;CBS Publishers and distributors.pvt ltd;5th edition;vol 3
64

65. • EXTRACRANIAL COURSE
• The nerve crosses the lateral side of the base of the styloid
process .
• Nerve enters the posteriomedial surface of the parotid gland.
• Divides in to 5 branches.
65

66. • Branches And Distribution
A) Within the canal
B) As it exits from stylomastoid foramen.
C) Terminal branches within the parotid gland.
D) Communicating branches with adjacent cranial nerves.
66

67. Greater Petrosal Nerve
Postsynaptic parasympathetic
fibers from this ganglion
innervate the lacrimal gland
Within the canal
Nerve To Stapedius
Stapedius muscle
Chorda Tympani
Parasympathetic fibers of the
chorda tympani synapses in
the submandibular ganglion.
67

68. FACIAL NERVE AT ITS EXIT FROM STYLOMASTOID
FORAMEN
POSTERIOR AURICULAR DIGASTRIC STYLOHYOID
Auricularis Posterior,
Occipitalis,
Intrinsic Muscles On
The Back Of Auricle
Stylohyoid MusclePosterior Belly
Of Diagastic
68

69. TERMINAL BRANCHES WITHIN PAROTID GLAND
TEMPORAL BUCCAL ZYGOMATIC
MAGINAL
MANDIBULAR
CERVICAL
Auricularis anterior,
Auricularis superior,
Frontalis,
Orbicularis oculi,
Corrugator supercilli,
Instrinsic muscle on
the lateral side of the
ear
Orbicularis
oculi
Upper branch run above
parotid duct and lower
branch below the duct
and supply muscles in
vicinity especially
buccinator
Lower lip and
chin
Platysma
69

70. 70
Human anatomy; BD chaurasia;CBS Publishers and distributors.pvt ltd;5th edition;vol 3

71. Ganglion
71

72. 72

73. 73
Geniculate ganglion
Location-first bend of facial nerve medial wall of middle ear
Ganglion –sensory
Taste fibres are present in the nerve

74. Clinical examination
MOTOR FUNCTION
-Inspect carefully for any
asymmetry of face as a whole
-Ask the patient to
- wrinkle his forehead or look up
above his head.
- to bare his teeth
- Test power by giving instructions
“screw your eyes tightly shut and stop
me from opening them” and blow out
with cheeks
74

75. -Instruct the patient not to speak during the test
-Ask to put out his tongue
-Use cotton buds dipped in sugar (sweet), salt,
vinegar (sour) and quinine (bitter). Apply them to the
anterior two third of tongue
-Between each test ask the patient to rinse his mouth with water
Taste
75

76. Clinically
a) Supra-nuclear lesions
-upper motor neuron lesions of VII
-lower part of opposite side of face is
paralysed
b) Infra-nuclear lesions-->
-lower motor neuron lesions of VII
-whole of face of same side is paralysed
76

77. c) Ramsay Hunt syndrome
-special form of Zoster infection of geniculate ganglion.
-characterized by
- Bell’s palsy
- unilateral vesicles of
external ear
- vesicles of oral mucosa.
-Hoarseness , tinnitus ,
vertigo.
77

78. d) Bell’s Palsy
-k/as 7th nerve paralysis , facial paralysis
-considered as idiopathic facial paralysis
- Def- an abrupt, isolated, unilateral, peripheral facial n.
paralysis without detectable causes.
Etiology-
Head injury, tumor, hypertension, sarcoidosis, herpes virus or
infarction of the7th N
78

79. • Clinical manifestations-
-slight pain around one ear followed by abrupt
paralysis of muscles on that side of face.
• Melkerson – Rosenthal syndrome--
facial paralysis, non pitting non inflammatory painless edema
of face, cheilitis granulomatosa & fissured tongue.
79

80. Paralysis of upper eyelid—
Difficulty in closing eye & lubricating cornea 
corneal ulceration
Chorda tympani n. Paralysis-
Loss of taste sensation
Buccinator m paralysis-
Food accumulates in the
cheek
80

81. orbicularis oris paralysis-
marked asymmetry of the mouth, drooling of saliva
occipitofrontalis paralysis—
loss of wrinkle on the forehead
81

82. • Progress…….
Bell’s palsy symptoms progress very quickly The paralysis
should peak within several days, never longer than 2 weeks.
• Do people recover from Bell’s palsy?
Yes.
Approx 50% patients complete recoveries in a short time.
Another 35% patients good recovery < 1 year.
“Average” recovery time 2 weeks to a few months.
82

83. Cranial nerve-VIII
Vestibulocochlear Nerve:
(sensory)
83

84. • Origin: Medulla oblongata
• Opening to the Skull: Internal acoustic meatus
• A special sensory nerve, consist of two kinds of fibers, the vestibular
and the cochlear
• Mediate sound reception and balance.
84

85. 85
Vestibular Branch
• Vestibular branch arises from the vestibular organs of
equilibrium and balance.
• Relays afferent information related to the position and
movement of the head
• Central processes of the vestibular nerve are located in the
vestibular ganglion, which is situated in the internal acoustic
meatus.
• Its fibres conduct impulses to the vestibular nuclei within the
pons and medulla oblongata.
• Fibres from there extend to the thalamus and cerebellum.

86. 86
Cochlear Branch
• Cochlear branch arises from the Organ of Corti in the cochlear
and is concerned with hearing.
• It conveys impulses through the spiral ganglion to the cochlear
nuclei within the medulla oblongata.
• From there fibres extend to the thalamus and synapse there
with neurons that convey the impulses to the auditory areas of
the cerebral cortex.

87. 87
Clinically
Damage produces: • Deafness
• Dizziness
• Nausea
• Loss of balance
• Nystagmus
Examination
Vestibular portion: Patient asked to walk a straight line portion:
Cochlear Tested with tuning fork.
Comment
Not usually tested unless patient complains of dizziness or
balance problems.

88. 88
Cranial nerve-IX
Glossopharyngeal Nerve(Sensory)

89.  Ninth cranial nerve.
 It is motor to stylopharyngeous, secretomotor to parotid
gland, gustatory to posterior 1/3rd of the tongue including
circumvallate papillae.
 It is sensory to pharynx, tonsils, soft palate, the posterior 1/3rd
of tongue, carotid body and carotid sinus.
89

90. Course And Origin
Ventral surface of medulla
oblongata
Posterior cranial fossa
Central part of jugular
foramen
Between internal jugular
vein and external carotid
artery
90

91. Deep to styloid process
Between internal and external
carotid arteries at posterior
border of stylopharyngeus
Reaches pharynx between
middle and inferior constrictor
deep to hypoglossus.
91

92. Branches & Distribution
BRANCH SUPPLY
Tympanic branch
Middle ear, auditory tube, lesser petrosal
nerve relay in otic ganglion join
auriculotemporal nerve and supplies
parotid gland.
Sinocarotid branch
Carries Baroreceptors : carotid sinus
Chemoreceptors : carotid body
Tonsilary & palatal branches
Supply sensory fibers to Palatine tonsil &
soft palate.
Lingual branches
Supply to posterior 1/3rd of the tongue
including circumvallate papillae.
Pharyngeal branches
Sensory to mucous membrane of
pharynx.
Muscular branches Stylopharyngeus muscle
92

93. 93

94. Examination
Gag reflex
• Sensation supplied by the glossopharyngeal nerve is different
in quality to that supplied by the trigeminal.
• Place a finger on the anterior part of the tongue (V) and then
the posterior part (IX) to demonstrate this.
• The gag reflex is mediated by the glossopharyngeal (afferent
limb) and the vagus (efferent limb).
• It is a functional test of both nerves.
94

95. Cranial nerve-X
Vagus nerve: Mixed
95

96. Vagus nerve is a mixed nerve.
• Containing approximately 80% sensory fibers.
• It supplies :
Organs of voice and respiration with both motor and
sensory fibres .
Pharynx (except stylopharyngeus), oesophagus, stomach
and heart with motor fibres.
One muscle of the tongue (palatoglossus).
The muscles of the soft palate (except tensor veli palatini ).
• It is the most extensive cranial nerve, consisting of many
branches.
96

97. COURSE OF VAGUS NERVE
• The nerve runs from the lower brainstem through the base of
the skull to travel in the neck with the carotid artery and
jugular vein.
• It then penetrates the chest to travel to the heart and lungs.
• It continues on to the abdomen where it breaks into a
network of nerves to the abdominal organs.
• Supplies motor and sensory parasympathetic fibres to pretty
much everything from the neck down to the first third of the
transverse colon.
97

98. • It is involved in, amongst other things, such as heart rate,
gastrointestinal peristalsis, sweating, and speech (via the
recurrent laryngeal nerve) and also the controls a few skeletal
muscle of the pharynx and larynx:
▫ Levator veli palatini muscle
▫ Salpingopharyngeus muscle
▫ Stylopharyngeus muscle
▫ Palatoglossus muscle
▫ Palatopharyngeus muscle
▫ Superior, middle and inferior pharyngeal constrictors
98

99. Clinically
• Dysphagia
• Hoarseness
• Uvula points away from the affected side
• Loss of gag and cough reflex
99

100. 100
Cranial nerve-XI
Accessory nerve: (Motor)

101. 101
Cranial root
Muscles of soft palate (except tensor veli palatini)
Muscles pharynx (except styopharyngeus)
Muscles of larynx (except cricothyroid)
Spinal root
Sternocleidomastoid
Trapezius muscle
• Origin: Medulla oblongata
• Opening to the Skull: Jugular foramen

102. Function
▫ Laryngeal movement; soft palate
▫ Motor impulses to trapezius and
sternocleidomastoid muscles for
movement of head, neck,and
shoulders
▫ Proprioception from muscles that
move head, neck, and shoulders
102

103. 103
Examination
Patient asked to shrug shoulders against resistance of
examiner’s hand and to rotate head against resistance.
Comment
Sides should show uniformity of strength.
Clinically:
• Paresis of the laryngeal and pharyngeal muscles leading to
dysphonia and dysphagia.
•Paresis of the trapezius and sternocleidomastoid muscle
following neck dissection for tumour surgery.

104. 104
Cranial nerve-XII
Hypoglossal Nerve(motor)

105. • Fibers arises : From the hypoglossal Nucleus which lies in the
Medulla, in the floor of the fourth verticle deep to hypoglossus
triangle.
• Opening to the skull : Hypoglossal canal.
• Hypoglossal nerve is a motor nerve that supplies all the intrinsic
muscles of the tongue as well as the styloglossus, the hyoglossus,
and the genioglossus muscles.
105

106. • Examination
Patient asked to protrude tongue; tongue thrust may be resisted
with tongue blade.
• Comment
Tongue should protrude straight out; deviation to side indicates
ipsilateral-nerve dysfunction; asymmetry, atrophy, or lack of
strength should be noted
Clinically
Hypoglossal nerve lesions
Damage to the hypoglossal nerve in the neck would result in an
ipsilateral lower motor neuron lesion. This would cause the
protruded tongue to deviate to the side of the lesion
106

107. 107

108. Secretomotor fibres
108

109. Parotid Gland
109
1.Parasympathetic fibers:
These are secretomotor
• preganglionic fibers – inferior salivatory
nucleus 9 th nerve rely otic ganglion
• postganglionic fibers auriculotemporal
nerve gland
2.Sympathetic nerves are vasomotor and
are derived from plexus around external
carotid artery.
3.Sensory nerves come from
auriculotemporal nerve.

110. Submandibular and Sublingual Gland
110

111. 111
•The secretomotor pathway begins near superior salivatory nucleus.
•Preganglionic fibers pass through the sensory root of facial nerve, the
geniculate ganglion, the chorda tympani and the lingual nerve to reach
submandibular ganglion. Postganglionic fibers emerge from the
ganglion and enter submandibular gland.
Human anatomy; BD chaurasia;CBS Publishers and distributors.pvt ltd;5th edition;vol 3

112. 112

113. 113

114. Significance In Prosthodontics
114

115. Significance of the mental nerve
Extreme ridge resorption (mandibular)
Mental foramen opening lies on or near
the crest of ridge
Denture compress mental nerve
1) Pain
2) numbness of lower lip
Rx-
-relief in this area
-increasing opening of mental foramen
downward toward inferior border of body
of mandible
115

116. Significance of the nasopalatine nerve
Nerve passes through incisive foramen
Denture compress this nerve
Relief is given at this area
116

117. Importance of the modiolus
Supplied by facial nerve
Contraction of modiolus
Corner of mouth presses
against the premolars
Occlusal table closed
Food not escape from
corner of mouth
117

118. 118
References

119. • Gray’s anatomy of human body; Richard L.Drake,
A.waynevoge,Adam W.M.mitchele:2nd edition
• Hand book of local anesthesia;Stanley F.MALAMED;4TH
edition:mosby
• Human anatomy; BD chaurasia;CBS Publishers and
distributors.pvt ltd;5th edition;vol 3
• Oral medicine;Burket’s;10th edition
• Text of oral pathology ;Shafer’s ;5th edition
• Cranial nerve functional anatomy;Stanley Monkhouse;
Cambridge University Press,2006;2nd edition
• Atlas of human anatomy:Frank H. Netter:6th edition
• Anatomy of human body:Henry Gray
• Thieme altas of anatomy head and neuroanatomy:Micheal
Schuenke Erik Schulte Udo Schumacher, Lawrence M.Ross
Edward D.Lamperti Ethan Taub, Markus Volf KanWesker
2010
• Human anatomy;kent-van-de-graff:6th edition;2001
119

120. 120
Thank You