TRIGEMINAL NERVE

1. Presented by ,
ZUNAIDHA

2. CONTENTS
Introduction
Nuclei
Origin and course of Trigeminal
Nerve
Trigeminal Ganglion
Branches – OPHTHALMIC
MAXILLARY
MANDIBULAR
Examination of Trigeminal Nerve
Applied Anatomy
Conclusion
References

3. Introduction
Cranial nerves are the nerves that emerge directly from the brain.
They are 12 in number.
The 12 pairs of cranial nerves supply muscles of eyeball, face, palate, pharynx,
larynx, tongue and two large muscles of the neck.
Besides these are afferent to special senses like smell ,sight, hearing, taste and
touch.

4. CRANIAL NERVES
OLFACTORY
GLOSSOPHARYNGEAL
ABDUCENT
TRIGEMINAL ACCESSORY
OPTIC
FACIAL
VESTIBULOCOCHLEAR
OCULOMOTOR
VAGUSTROCHLEAR
HYPOGLOSSAL

5.  Afferent nerves: part of the general somatic afferent
system.
The type of nerve that carries sensory nerve impulses from the
periphery towards the central nervous system
 Efferent nerve : that conveys impulses toward or to
muscles or glands. Synonyms: motor nerve.
.
Trigeminal nerve
Mixed nerve

6.  Various nuclei associated with the fifth nerve are situated within the pons.
1. Main Sensory nucleus ( tactile sensation )
2. Mesencephalic nucleus ( proprioceptive sensibility )
3. Spinal tract nucleus ( pain and temperature)
4. Motor nucleus

7.  Largest cranial nerve.
 Nerve of first brachial arch.
Meninges
Skin of anterior part of the head
Nasal & oral cavities
Teeth and gums
FUNCTIONS:
Muscles of Mastication
Mylohyoid
Anterior Belly of Digastric
Tensor Tympani
Tensor Veli Palatini
OPHTHALMIC
MAXILLARY
MANDIBULAR
The sensory fibers are present in
all three divisions; Only
Mandibular division contains
motor fibers.
TYPES OF FIBERS:
 Small motor root
 Large sensory root
FUNCTIONAL COMPONENT

8. ORIGIN

9. Course and attachments

10. MOTOR ROOT
 It arises separately from the sensory root originating in main nucleus in pons
 Its fibers travel anteriorly along with sensory fibers, but separately to the region of
trigeminal ganglion.
 At the semilunar ganglion it passes in a lateral and inferior direction under the ganglion
towards foramen ovale, through which it leaves the middle cranial fossa along with the
sensory root of mandibular nerve.
 After it exits the skull, it unites with the sensory root of mandibular nerve and forms a
single nerve trunk.
 It supplies the following muscles:
Muscles of Mastication
Mylohyoid
Anterior Belly of Digastric
Tensor Tympani
Tensor Veli Palatini

11. SENSORY ROOT
 Sensory root fibers of trigeminal nerve comprises of the central processes of
ganglion cells located in trigeminal ganglion.
Cornea and Conjunctiva of The Eye;
Mucosa of The Sinuses,
Nasal and Oral Cavities;
Dura of The Middle, Anterior, and Part of the
Posterior Cranial Fossae
 A lesion of the sensory fibers produces hypesthesia or anesthesia of the area supplied

12. TRIGEMINAL GANGLION
(Semilunar / Gasserian Ganglion)
 Sensory root fibers enter the concave portion of each crescent and the three sensory
divisions of Trigeminal nerve exit from convexity.
 Blood supply to the ganglion is through the ganglionic branches of the ICA & the accesory
meningeal artery which enters through the foramen ovale.
RELATIONS:

13. The Trigeminal ganglion contains pseudounipolar ganglion cells whose internal branches
pass into the pons.
These internal branches form the sensory root of the trigeminal nerve

14.  First division
 Carries sensory fibers from the structures derived from fronto-nasal process.
 Leaves the cranial cavity through Superior Orbital Fissure.
OPHTHALMIC NERVE
Functions
 Eyeballs
 Skin of upper face and anterior scalp
 Lining of upper part of nasal cavity
 Air cells
 Meninges of anterior cranial fossa
 Cilliary and iris muscles for accommodation
and pupillary constriction.
 Lacrimal gland

15. Branches :
1. Lacrimal nerve
2. Frontal nerve
Supratrochlear
Supraorbital
3. Nasocilliary nerve
Short cilliary nerve
Long cilliary nerve
Anterior and Posterior ethmoidal
Infratrochlear

16. MAXILLARY NERVE
• Second division.
• It is purely sensory.
• The nerve leaves the middle cranial fossa through the foramen rotundum
to reach the Pterygopalatine fossa
Functions :
 Skin of face between lower eyelid and the mouth.
 From nasal cavity and sinuses
 Maxillary teeth and PDL tissues.
 Receives postganglionic
Parasympathetic fibers from
pterygopalatine ganglion
which
pass to the
LACRIMAL,NASAL and
PALATINE GLANDS.
Others convey taste fibers

17. Maxillary nerve gives off branches in four regions:
 Within the cranium : Middle Meningeal Nerve
 In the Pterygopalatine Fossa: Ganglionic branches
Zygomatic Nerves
Posterior Superior Alveolar Nerves
 In the Infraorbital Canal: Middle Superior Alveolar Nerves
Anterior Superior Alveolar Nerves
 On the face: Inferior Palpebral
Lateral/External Nasal
Superior Labial

18. Meningeal branch:
 Immediately separating from Trigeminal ganglion , the Maxillary nerve
gives off a small branch , Middle Meningeal Nerve.
 It is given off near the foramen rotundum.
 It travels along with Middle meningeal artery.
 It provides sensory innervation to the duramater of the anterior &
middle cranial fossae.

19. Maxillary nerve gives off branches in four regions:
 Within the cranium : Middle Meningeal Nerve
 In the Pterygopalatine Fossa: Ganglionic branches
Zygomatic Nerves
Posterior Superior Alveolar Nerves
 In the Infraorbital Canal: Middle Superior Alveolar Nerves
Anterior Superior Alveolar Nerves
 On the face: Inferior Palpebral
Lateral/External Nasal
Superior Labial

20. The branches of the Pterygopalatine ganglion are:-
I. Orbital branches: Periosteum of orbit.
II. Palatine branches:
1.Anterior/Greater palatine
2.Lesser palatine
III. Nasal branches:
1.Posterior superior lateral
2.Nasopalatine/Sphenopalatine
IV. Pharyngeal branches: mucous membrane of Nasopharynx

21. Zygomatic Nerves :
I. Zygomaticotemporal nerve
II. Zygomaticofacial nerve
 Sensory innervation to skin over zygomatic region.
 Also conveys post ganglionic para symp fibers from pterygopalatine ganglion to
Lacrimal nerve and glands.
 It exits the fossa ,travels anteriorly, enters the orbit through infraorbital fissure and runs
along the lower part of lateral wall of the orbit.
 Then it enters the zygomatic bones and divides into two branches

22. Posterior Superior Alveolar Nerve:
 Descends from the main trunk of Maxillary nerve in the fossa.
 External branch provides sensory innervation to buccal gingiva in posterior maxilla.
 Other branch enters the maxilla through the posteriorolateral wall of sinus, and provides
sensory innervation to mucous membrane of sinus,alveoli,PDL and pulpal tissues of
maxillary molars.
 Mesiobuccal root of first molar is
not innervated by PSAN in 25% of
individuals.

23. Maxillary nerve gives off branches in four regions:
 Within the cranium : Middle Meningeal Nerve
 In the Pterygopalatine Fossa: Ganglionic branches
Zygomatic Nerves
Posterior Superior Alveolar Nerves
 In the Infraorbital Canal: Middle Superior Alveolar Nerves
Anterior Superior Alveolar Nerves
 On the face: Inferior Palpebral
Lateral/External Nasal
Superior Labial

24. Infraorbital Nerve:
 Middle Superior Alveolar Nerve
 Anterior Superior Alveolar Nerve
 It passes forwards along the floor of the orbit, sinks into the groove , then enters the canal
and emerges on the face through IO foramen.
 MSAN-premolars ,MB root of first molar,PDL tissues,buccal soft tissue.
 ASAN- C.I, L.I , Canines, PDL tissues, buccal bone and gingiva of these teeth.
 DENTAL PLEXUS : The innervation of
roots of all the teeth ,
bone and PDL structures are derived
from terminal
branches of larger nerves.
- composed of small nerve fibers from
three superior Alv Nerves.
- Nerves emerging :
- 1. Dental nerves
- 2. Interdental branches
- 3. Inter radicular branches

25. Maxillary nerve gives off branches in four regions:
 Within the cranium : Middle Meningeal Nerve
 In the Pterygopalatine Fossa: Ganglionic branches
Zygomatic Nerves
Posterior Superior Alveolar Nerves
 In the Infraorbital Canal: Middle Superior Alveolar Nerves
Anterior Superior Alveolar Nerves
 On the face: Inferior Palpebral
Lateral/External Nasal
Superior Labial

26. Branches on face:
i. INFERIOR PALPEBRAL : skin of lower eyelid, conjunctiva.
ii. LATERAL NASAL : skin on the lateral aspect of the nose.
iii. SUPERIOR LABIAL : skin and mucous membrane of the upper lip.

27. MANDIBULAR NERVE
• Third division and the largest branch.
• Mixed nerve.
• Nerve of first branchial arch.
Functions : MOTOR
 Muscles of Mastication
 Mylohyoid
 Anterior Belly of Digastric
 Tensor Tympani
 Tensor Veli Palatini
Functions : SENSORY
 Skin over the mandible
 Side of cheek and temple
 Oral cavity and its contents
 External ear
 Tympanic membrane & TMJ
 Some of the branches also
convey parasympathetic
secretomotor fibers to salivary
glands and taste fibers from
anterior portion of tongue.

28.  From undivided nerve: Meningeal branch
Nerve to medial pterygoid.
 From the anterior trunk: Deep temporal nerve
Massetric nerve
Nerve to lateral pterygoid
Buccal nerve/Buccinator nerve.
 From the posterior trunk: Inferior alveolar nerve
Lingual nerve
Auriculotemporal nerve

29. Meningeal nerve:
 Is given off from the nerve just after the union of motor and sensory roots.
 It enters the skull through the foramen spinosum along with MMA.
2. Nerve to the medial pterygoid:
 It is a slender branch that supplies to the deep surface of the muscle.
i. Cartilaginous part of Eustachian tube
ii. Dura of middle and anterior cranial fossa
iii. Mastoid air cells
i. tensor tympani
ii. tensor veli palati muscles.

30.  From undivided nerve: Meningeal branch
Nerve to medial pterygoid.
 From the anterior trunk: Deep temporal nerve
Massetric nerve
Nerve to lateral pterygoid
Buccal nerve/Buccinator nerve.
 From the posterior trunk: Inferior alveolar nerve
Lingual nerve
Auriculotemporal nerve

31. Temporal branches
 Temporalis is supplied through the anterior, middle and posterior deep temporal
nerves.
 These nerve pass upwards above the lateral pterygoid to reach the deep surface of
the temporalis.
 Anterior branch may arise from the buccal nerve and posterior branch may arise
from massetric nerve.

32. Nerve to Masseter:
 Passes above the upper head of lateral pterygoid ,proceeds laterally behind the
temporalis and through the mandibular notch sinks into the masseter muscle.
 It gives off its branches to TMJ.

33. Nerve to lateral pterygoid
May be independent or may arise from the buccal nerve

34. Buccal Nerve
 It is the only sensory nerve from the anterior division.
 It runs through the muscles of infratemporal fossa to reach the surface of the
buccinator muscle.
 It supplies the skin, superficial to the muscle and the mucous membrane lining its
deep surface.

35.  From undivided nerve: Meningeal branch
Nerve to medial pterygoid.
 From the anterior trunk: Deep temporal nerve
Massetric nerve
Nerve to lateral pterygoid
Buccal nerve/Buccinator nerve.
 From the posterior trunk: Inferior alveolar nerve
Lingual nerve
Auriculotemporal nerve

36. INFERIOR ALVEOLAR NERVE
 It is a largest terminal branch of the posterior division of mandibular nerve.
 It lies deep to the lateral pterygoid muscle.
 Emerges at the lower border of this muscle, the nerve runs downwards and forwards
deep to the ramus.
 It passes between the
sphenomandibular ligament &
the ramus to enter the mandibular
foramen.

37. Additional mental foramina
exist, with a reported prevalence of 9%. These canals
are often smaller and located more posteriorly
(Oliveira‐Santos et al. 2011).
 It runs forwards in the canal just below the teeth and ends at the mental foramen ,
INCISIVE ( canine , incisors )
MENTAL (skin over the chin and the lip )

38. MYLOHYOID NERVE :
 It is given off before the nerve enters the canal & contains both sensory & motor
fibres.
 It pierces the sphenomandibular ligament, descends in a groove in the medial
side of the ramus & passes beneath the mylohyoid line supplying the mylohyoid
muscle as well as the anterior belly of the digastric.

39. Auriculotemporal Nerve:
 COURSE: The auriculotemporal nerve arises by a medial & lateral roots, that
enclircle the MMA & unite behind it just below the foramen spinosum.
 The united nerve passes backwards, deep to the lateral pterygoid muscle & passes
between the sphenomandibular ligament & the neck of the condyle.
 It then passes laterally behind the TMJ i.r.t. to the upper part of the parotid.

40.  It emerges from behind the TMJ, ascends posterior to the superficial temporal
vessels & crosses the posterior root of the zygomatic arch.
 It finally turns upwards into the scalp and ends by dividing to branches that
supplying the skin over the temple.

41. Branches of the Auriculotemporal nerve:
1. Parotid branches-----secretomotor, vasomotor.
2. Articular branches--- TMJ.
3. Auricular branches---to the skin of the helix & tragus.
4. Meatal branches----- Meatus of the tympanic membrane
5. Terminal branches----Scalp over the temporal region

42. LINGUAL NERVE:
 COURSE :It lies between the ramus of the mandible & the muscle in the
pterygomandibular space.
 Its upper part runs downwards deep to the lateral pterygoid muscle.
 It then passes deep to reach the side of the tongue.
 Here it lies in the lateral lingual sulcus against the deep surface of the
mandible on the medial side of the roots of the third molar tooth where it is
covered only by mucous membrane of the gum.

43.  From here it passes on to the side of the tongue where it is crosses the styloglossus & runs on the
lateral surface of the hyoglossus & deep to the mylohyoid in close relation to the deep part of the
submandibular gland &its duct.
 It gives off sensory fibres to the tonsil & the mucous membrane of the posterior part of the oral
cavity.

44. EXAMINATION OF TRIGEMINAL NERVE
 Sensation Function
 Motor Function
 Corneal reflex
 Test jaw jerk
 Sensation Function:
Touch, pain and temperature are
tested over the temple, cheek and jaw,
corresponding to the ophthalmic,
maxillary and mandibular divisions of
the trigeminal nerve
 use sterile sharp item on forehead, cheek, and jaw.
If any abnormality present test for the thermal sensation
and light touch.

45.  Motor Function : mandibular nerve is tested clinically , by asking
the patient to clench the teeth and then feeling for the contracting
muscles on both sides.
Protrusion of the jaw and movements
to each side, are by the pterygoid
muscles and can be assessed against
resistance

46.  Corneal reflex: The examination is a part of some neurological exams,
particularly when evaluating coma.
Damage to the ophthalmic branch (V1) of the 5th cranial nerve results in
absent of corneal reflex when
the affected eye is stimulated.
Touch edge of cornea using a
wisp of cotton wool
Normal response = Direct and
consensual blinking

47. The Jaw jerk is one of the deep tendon or stretch reflexes.
Normal = slight closure of the jaw
Abnormal = brisk complete closure of the jaw – UMN lesion
With nuclear or Infranuclear lesions, the reflex is absent.
 Test Jaw Jerk: Have the jaws half open
Then place your index finger on the
mandible and tap your finger gently b
with a reflex hammer.

48. APPLIED ANATOMY

49.  Trigeminal neuralgia
 Peripheral lesions
 Trigeminal nerve injuries
 Post herpetic neuralgia
 Frey’s syndrome
 Post surgical complications
 Nerve blocks

50. TRIGEMINAL NEURALGIA / Tic doloureux
(Trifacial Neuralgia/Fothergill’s
Disease)
Definition : Sudden, unilateral, severe ,brief, stabbing, lancinating,
paroxysmal, recurring pain in the distribution of one or more
branches of Trigeminal nerve.
JOHN LOCKE (1677) – full description with its treatment
NICHOLAUS ANDRE (1756) – ‘Tic Doulourex
JOHN FOTHERGILL (1773) – Detailed description – referred
as ‘Fothergills disease’.
Pain is always accompanied by brief facial spasm or ‘TIC’
‘Tic Douloureux’’ (painful jerking)

51. Clinical Features:
 Incidence - 4 in 100000 persons.
 > 40 yrs of age (average age of onset 50 yrs).
 Women (58%) > men.
 Right side > left. (1.7: 1)
 V3 > V2 division > V1 (5% )
 Pain last for few seconds to minute.
Trigger Points - Nasolabial Fold,
Vermillion Border of Lip,
Midfacial
Periorbital Skin
cheek , teeth and gums
 The pain is sudden, unilateral, intermittent, paroxysmal, sharp,
shooting, lancinating,
shock like pain, elicited by slight touching superficial ‘trigger
points’ which radiates from
that point ,across the distribution .

52.  Extreme condition – motionless face (Frozen or
mask like face).
 Paroxysms occur in cycles, each cycles lasting for
weeks or months.
 With each attack pain seems to become more
intense and unbearable.
 Pain is unilateral
 Attacks occur during the day.
 Male patients avoid shaving
 Oral hygiene is poor as patients avoid
brushing of teeth
 Leads to poor quality of life due to
excruciating pain.

53. Types of trigeminal neuralgia:
• Trigeminal neuralgia type 1 (TN1)
- classic form
- Not constant.
- Idiopathic
• Trigeminal neuralgia type 2 (TN2)
- atypical
- constant (more aching, throbbing and burning sensations)
• Symptomatic trigeminal neuralgia (STN
- underlying cause (multiple sclerosiss)

54. DIAGNOSIS :
“Sweet Criteria” (White and Sweet )
1. Pain is paroxysmal
2. Pain may be provoked by light touch (Trigger
Zone )
3. The pain is confined to trigeminal distribution
4.The pain is unilateral
5.The clinical sensory examination is normal
Proper clinical examination along with the history is mandatory

55. TREATMENT :
Primary medication :
 Carbamazepine(Tegretol) 100 mg
(Phenytoin, Gabapentin, clonazepam ,Lamotrigine, Trichloroethylene,Valp
acid, Baclofen,Benzodiazepam)
Percutaneous Management :
 Injection of 60 to 90% alcohol/ percutaneous glycerol in the nerve
trunk or ganglion.
 Radiofrequency Ablation.

56. Surgical Management :
 Peripheral neurectomy
 Microvascular Decompression
 Balloon compression of the root ent
 Percutaneous needle thermal Rhizoto
 Gamma Knife Radiosurgery

57. Microvascular decompression (MVD) has become an
accepted surgical technique for the treatment of TN
o Overall 70-80% of patients can become pain free post procedure.
o Barker et al reviewed 1185 patients, 70% of patients pain free withou
for TN 10 years postoperatively.
o Tronnier et al also showed excellent outcomes in 65% patients 10 yea

58. Newer Approaches :
 Physiologic inhibition of pain by transcutaneous neural stimulation
 Acupunture
Psychological
Approach :
 Biofeedback
 Psychiatric
Counselling
 Hypnosis

59.  Peripheral lesions involving the sensory portion of the trigeminal at an
distal to the pontine exit can produce ipsilateral pain and/or varying
Craniofacial Trauma
Basilar Skull Features
Dental Trauma, Maxillary Sinusitis
Primary / Metastatic Tumors
Aneurysm of the Internal Carotid Artery
Cavernous Sinus Thrombosis
Lupus, Scleroderma
Sjøgren's Syndrome
PERIPHERAL LESIONS :
Trigeminal root lesions: prone to
produce facial pain that is often
misdiagnosed as tic douloureux or
tooth pain.
Midpontine lesions (unilateral )
 ipsilateral decrease in tactile sensation of the face due to
involvement of the main sensory nucleus, and
 ipsilateral paralysis of the masticatory muscles when the motor
nucleus is involved.

60. HORNER'S SYNDROME can be produced by lesions of the
Nasocilliary nerve as it runs with the ophthalmic division.
MIOSIS
PTOSIS
ANHYDROSIS
ENAPHTHALMOS

61. Functional loss Location
Pain, temperature, touch
over entire body, including
face ipsilaterally
Lateral rostral pons and
above
Masticatory muscle
paralysis and pain,
temperature, touch over
face ipsilaterally
Midpons
Pain, temperature over
face ipsilaterally; pain,
temperature over body
(and occasionally face)
contralaterally
Lateral inferior pons or
lateral medulla
CENTRAL LESIONS

62.  The muscles of mastication produces protraction , retraction, elevation,
depression , lateral movements .
 The mandible upon opening deviates toward the paralyzed side when ther
unilateral paralysis of the
masticatory muscles.
 This direction of the mandible is due to the action
of normal pterygoids in the opposite side.
 The mandible droops, and no jaw movement is possible
with bilateral paralysis.
 Thus involved muscles atrophy is due to Nuclear or
Infranuclear lesions.

63. • Described by FREY.
• Condition of localised gustatory sweating and flushing of areas
supplied by ATN.
ETIOLOGY
• Parotid gland and TMJ
surgery
• Facial wound / Parotid
Abscess
• Suppurative parotitis
FREY’S SYNDROME

64. Clinical features :
• Pain in ATN distribution
• Gustatory sweating , erythema
• Flushing of affected side on the face
• Sweating in preauricular , behind the pinna
• Starch Iodine test is positive
Treatment
1. TOPICAL AGENTS –
Commercial antiperspirants – aluminium chloride
hexahrdrat
Anti cholinergic preparations -( propanthalene,topical
glycopyrolate )
Benzodiazepines , diltiazem.
 Botulinum toxin injections.
2. RADIATION THERAPY – dose of 50 Gy
3. SURGICAL PROCEDURES – Skin excision, ATN
Section
Tympanic Neurectomy.

65. TRIGEMINAL NERVE INJURY:
Causes:
Trauma, Tumours,
Improper LA
techniques.
Aneurysms,
Meningeal Infection
Poliomyelitis
Generalized
Polyneuropathy
Impaction of third
molars
Implant placement
Cyst/tumor removal
 Distruction of sensory and motor nuclei in the pons and medulla
by intramedullary tumours or vascular lesions
 Temporary deficit
 Permanent deficit
Incidence : IAN = 1.0-7.1 % LN = 0.02-0.06%
(American Association of Oral and Maxillofacial Surgeons rep
• Paralysis of the muscles of mastication
with
deviation of the mandible toward
the side of lesion.
• Loss of inability to appreciate soft
tactile, thermal,
or painful sensations in the face.
• Loss of corneal and the sneezing
reflex.

66. NEUROPRAXIA:
Mild temporary injury caused by compression or
retraction of the nerve
No axonal degeneration
Temporary conduction block -sensory loss
Spontaneous recovery – 4 weeks or less time
No Surgical Intervention
SEDDON’S CLASSIFICATION : (1948)
AXONOTMESIS :
More significant injury
Wallerian degeneration of some
axons distally
Structure of the nerve remains
intact
Prolonged conduction fail
Recovery takes 1-3months
NEUROTMESIS :
Internal physiologic disruption of all layers of nerve
Wallerian degeneration of all axons distally
Permanent conduction blockade
Surgical intervention

67. Post Herpetic Neuralgia.
Post-herpetic neuralgia (PHN) is a chronic neuropathic pain condition
months or
more following an outbreak of shingles.
Constant Deep,
Aching, Or Burning
Pain
Paroxysmal,
Lancinating Pain
Hyperalgesia
Allodynia
 Complication of HERPES ZOSTER infection.
Etiology :
• Peripheral nerve
injury
• Atrophy of dorsal
horn cells in spinal
cord.
• Low grade infection
of the ganglion

68. TREATMENT
Prevention :Live attenuated varicella zoster
vaccine
Gabapentin / Pregabalin
Carbamazipine
Tricyclic Antidepressants (Amitriptylin ,Doxepin )
Topical Analgesics (5% lidocaine )
Tramadol

69.  CANCER SURGERIES: the tendency of squamous cell
carcinoma to affect the cutaneous branches places these nerves
at risk for injury during surgery.
 Similarly the tendency of salivary gland tumors (ACC) to spread
along perinueral spaces.
 TRANSANTRAL PROCEDURES: Paresthesias of the upper
lip, gums & teeth are a common complication.
 A lower third molar impaction may result in trauma to the
lingual nerve. Thus leading to the loss of sensation to the
anterior of tongue.
POST SURGICAL COMPLICATIONS OF SURG

70.  The mandibular incisive canal contains a true neurovascular bundle with
nervous sensory structures
 Its existence in edentulous patients is underlined by reported surgical
complications.
 Sensory disturbances, caused by direct trauma to the mandibular incisive can
bundle,
have been reported after implant placement in the interforaminal region (Jacobs
al. 2007)
 Sensory disorders may also result from indirect trauma caused by a hematom
the canal,
and as the latter acts as a closed chamber, pressure is exerted on the mandib
incisive canal bundle and this spreads to the main mental branch (Mraiwa et a
2003b).
These human dry mandibular
bone sections illustrate the presen
and
dimensional importance of the
mandibular
incisive nerve, even in edentulism.
The middle section actually shows
mandibular midline, confirming that
there is no true connection betwee
the
left and right sections.

71. Cross‐sectional slice of a cone‐beam
CT dataset
showing an osseointegrated implant
placed in an edentulous lateral incisor
region, on top of a prominent incisive
canal lumen.
Chronic pressure on the incisive
nerve resulted in neuropathic pain.
(Source: Jacobs & Steenberghe 2006. Reproduced with permission from John Wiley &
Sons.)

72.  The anterior superior alveolar nerve sometimes runs in a
clearly defined canal,
palatally of the canine (canalis sinuosus) (Shelley et al.
1999).
 Care should therefore be taken to avoid neurovascular
trauma during canine
implant installation.
 Nasopalatine nerve descends to the roof of the mouth
through the nasopalatine canal and
communicates with the corresponding nerve of the
opposite side and with the anterior palatine
nerve (Mraiwa et al. 2004).
 It has been described as forming a Y‐shape with the
orifices of two lateral canals,
and terminating at the nasal floor level.
 Occasionally, two additional minor canals carry the
nasopalatine nerves (foramina
of Scarpa).
 Mraiwa et al. (2004) point out a significant variability in

73. The outline of the common Y morphology of the nasopalatine
Anatomy of the nasopalatine canal.
View from the palate of an edentulous
dry skull showing the nasopalatine
foramen, formed at the articulation of
both maxillae, behind the incisor teeth.
In the depth of the canal, the orifices
of two lateral canals are seen

74.  The jaws are richly supplied by neurovascular structures, and it i
of utmost importance
to identify vital anatomic structures before carrying out a surg
procedure.
 All the canal structures contain a neurovascular bundle whose di
may be large enough
to cause clinically significant trauma if damaged.

75. Trigeminal Nerve Blocks For Various Clinical Procedures
Maxillary nerve
blocks :
Greater palatine nerve block
 hard palate
 Soft tissues overlying

76. Posterior Superior Alveolar Nerve Block Pulps of Max molars.
 Buccal periodontium
and bone.

77. Infraorbital
nerve block
 Pulps of Max anteriors
 Buccal periodontium and bone.
 Lower eyelid ,lateral nose,upper lip

78. Nasopalatine Nerve block
 Anterior hard palate

79. MANDIBULAR NERVE BLOCKS
Inferior Alveolar Nerve Block Mandibular teeth
 Body and inferior portion of ramus
 Buccal mucoperiosteum ,mucous membrane antr to
 Antr 2/3rd of the tongue and floor of oral cavity
 Lingual soft tissues

80. Mental Nerve Block  Buccal m.m antr to mental foramen
 Skin of the lower lip.

81. Buccal Nerve block
 Soft tissues and mucoperiosteum
buccal to mandibular molars

82. It is important that we dentists should be well aware of the
course and branches of the trigeminal nerve, to treat the patients
with confidence, to diagnose the pathological conditions and
moreover for the administration of local anesthesia more
efficiently without hurting the patient and to prevent further
complications.
CONCLUS
ION

83. References
1. Neelima Anil malik,Text book of Oral SURGERY
2. B.D Chaurasia ,Head and Neck Human Anatomy
3. Lindhe 6th edition
4. Handbook of Local Anesthesia, 5th Edition, Stanley F Malamed
5. Shafers 7th edition ,Text book of OralPathology
6. Clinical Methods: The History, Physical, and Laboratory Examinat
3rd edition by
H.Kenneth Walker

84. THANK
YOU