Trigeminal nerve

TRIGEMINAL NERVE AND ITS INVOLVEMENT IN PERIODONTOLOGY

1. TRIGEMINAL NERVE Guided By- DR.SHUBHRA VAISH Presented BY – DR.Lakshay Sethi DEPARTMENT OF PERIODONTOLGY & ORAL IMPLANTOLOGY PG 1st Year

2. CONTENT CRANIAL NERVES AND ITS PHYSIOLOGY INTRODUCTION TRIGEMINAL NUCLEI COURSE AND DISTRIBUTION TRIGEMINAL GANGLION DIVISIONS OF TRIGEMINAL NERVE APPLIED ANATOMY EXAMINATION OF TRIGEMINAL NERVE CONCLUSION BIBLIOGRAPHY CONTENTS

3. CRANIAL NERVES The 12 pairs of nerves are: I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducent VII Facial VIII Vestibulo -cochlear IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal There are 12 pairs of the cranial N erves . They are numbered 1 to 12 in the craniocaudal sequence of their attachment on the brain .

4. It is F ifth (5th) of twelve pairs of  cranial nerv es. Also Called Trigeminus or Trifacial Nerve Largest Cranial Nerve first described by Gabriele Fallopius Trigeminal nerve was proposed by Jacob Benignus Winslow Nerve OF 1st Branchial Arch. INTRODUCTION

5. TRIGEMINAL NUCLEI

6. A cranial nerve consists of motor fibres (motor nerve) or sensory fibres (sensory nerve) or both the motor and sensory fibres (mixed nerve ). MOTOR FIBRES SENSORY FIBRES Somatic efferent (SE) or general somatic efferent (GSE) Special visceral efferent (SVE ) General somatic afferent (GSA) General visceral efferent (GVE) General visceral afferent (GVA ) Special visceral afferent (SVA) S pecial S omatic A fferent (SSA)

7. Mixed Nerve – I.e Both Sensory To - MOTOR TO - Muscles of Mastication Anterior Belly of Digastric Tensor Tympani, Tensor Veli Palatini

8. Relations : Lateral – middle meningeal artery . Medial – internal carotid artery, cavernous sinus . Inferior – foramen lacerum , greater petrosal nerve, motor root of trigeminal nerve . Superior – parahippocampal gyrus .

9. TRIGEMINAL GANGLION ARTERIAL SUPPLY : Internal Carotid Artery . M iddle M eningeal A rtery . Accessory Meningeal Artery .

10.   (Semilunar Ganglion; ganglion semilunare ; Gasseri ; Gasserian ganglion) occupies a cavity ( cavum Meckelii ) in the dura mater covering the trigeminal impression near the apex of the petrous part of the temporal bone. It is somewhat crescentic in shape, with its convexity directed forward: medially, it is in relation with the internal carotid artery and the posterior part of the cavernous sinus . The motor root runs in front of and medial to the sensory root, and passes beneath the ganglion; it leaves the skull through the foramen ovale , and, immediately below this foramen, joins the mandibular nerve. The greater superficial petrosal nerve lies also underneath the ganglion.

11. Relations medial: motor root of the trigeminal nerve and  sphenoid bone lateral: posterior part of the  cavernous sinus ,  petrous apex  and petrous segment of the  internal carotid artery anterior: cavernous sinus and cavernous segment of the ICA posterior:  prepontine cistern inferior:  greater petrosal nerve  and  middle cranial fossa . Blood supply small ganglionic branches of the cavernous portion of the ICA accessory meningeal artery (from the  maxillary artery , via the  foramen ovale ) . Innervation The ganglionic epineurium is innervated by the  nervus spinosus  from the mandibular division of the trigeminal nerve which re-enters the skull via the  foramen spinosum .

12. COURSE AND DISTRIBUTION

13. The   trigeminal nerve  originates from three  sensory nuclei  ( mesencephalic , principal sensory, spinal nuclei of trigeminal nerve) and one  motor nucleus  (motor nucleus of the trigeminal nerve) extending from the midbrain to the medulla. At the level of the  pons , the sensory nuclei merge to form a sensory root . The motor nucleus continues to form a motor root. These roots are analogous to the dorsal and ventral roots of the spinal cord . In  middle cranial fossa , the sensory root expands into the trigeminal ganglion . The peripheral aspect of the trigeminal ganglion gives rise to 3 divisions:  O phthalmic  (V1 ), M axillary  (V2) M andibular  (V3).

14. OPTHALMIC NERVE (V1)   F irst division of the trigeminal nerve ORIGIN –TRIGEMINAL GANGLION TYPE - It is a purely sensory  nerve FUNCTION - Carries afferent stimuli of pain, light touch, and temperature from the upper eyelids and supraorbital region of the face, up to the vertex of the head .

15. The ophthalmic division (V1) travels forward through the cavernous sinus where it receives some fibers from the sympathetic plexus traveling with the internal carotid artery In the sinus, the nerve is located inferior to the trochlear nerve and lateral to the abducent and oculomotor nerves COURSE Trigeminal ganglion -> cavernous sinus -> superior orbital fissure -> lacrimal, frontal, nasociliary nerves (terminal branches) -> respective anatomical structures

16. I t subdivides into three terminal branches T he L acrimal , The Frontal N asociliary Nerve

17. OVERVIEW

18. LACRIMAL NERVE M ost lateral and thinnest branch of the ophthalmic nerve . Passes into orbit through lateral compartment of the Superior orbital fissure outside the tendinous ring . Connected with zygomaticotemporal branch of maxillary nerve . secretomotor fibres to lacrimal gland Supplies : lacrimal gland and skin of upper eyelid and conjunctiva .

19. FRONTAL NERVE Is the middle and thickest branch of the ophthalmic nerve . It runs directly beneath the roof of the orbit and superiorly to the superior palpebral levator muscle . DIVIDES Into – SUPRAORBITAL – lateral branch of the frontal nerve . -- the nerve gives off several   palpebral filaments   that supply the conjuctiva and the skin of the upper eyelid. 2. SUPRATROCHLEAR -- The   supratrochlear nerve is placed medial to the supraorbital nerve. -- Innervate the skin of the dorsum of the nose and adjacent skin of the upper eyelid .

20. SUPRATROCHLEAR N ERVE  Smaller nerve  Medial branch  Receives communication branches from infratrochlear nerve  Curves around superomedial margin of Orbi t supplies : median conjunctiva, Upper Lid and lower part of forehead  Lies between frontalis and corrugator supercilliary muscles SUPRAORBITAL N ERVE  Larger nerve  lateral branch  Passes through supraorbital notch  Divides in medial and lateral branches Lies beneath frontalis Muscle .  Supplies: conjunctiva, scalp upto vertex , mucous membrane of frontal sinus

21. NASOCILIARY NERVE N erve is the medial terminal branch of the ophthalmic nerve . It begins in the lateral wall of the anterior part of the cavernous sinus . C rossing over the superior side of the  optic nerve  it reaches the  anterior  ethmoid  foramen , where it divides to its own two terminal branches .

22. N asociliary nerve extends to the lateral branches in the following order going from proximal to distal to the root: Long Ciliary Nerve Short Ciliary Nerve Posterior  ethmoid nerve I n the area of the anterior ethmoid foramen, the nasociliary nerve extends to its two terminal branches : A nterior E thmoid N erve I nfratrochlear   nerve

23. Ciliary ganglion This ganglion belongs to the  autonomic nervous system  and is functionally added to the ophthalmic nerve . Lies in posterior part of orbital cavity . T he ciliary ganglion has preganglionic and postganglionic fibers .

24. Preganglionic  fibers  are – Sensory Sympathetic Parasympathetic Postganglionic  fibers   :- are the short  ciliary  nerves that extend forward while grouped around the optic nerve .

25. MAXILLARY NERVE V(2) SECOND division of the trigeminal nerve ORIGIN -- Trigeminal Ganglion . TYPE -- It is a purely sensory  nerve . Function – SUPPLIES Skin of the face over maxilla . Teeth of the upper jaw . Mucous membrane of the nose . T he maxillary sinus and palate .

26. COURSE C ourses forward through the lateral dural wall of the  cavernous sinus , inferiorly and laterally to the ophthalmic nerve . The nerve leaves the middle cranial fossa after it passes through the  foramen  rotundum  and enters the upper part of the  pterygopalatine  fossa . The fibers of the maxillary nerve leave the fossa by coursing forward through the pterygomaxillary fissure and then enter the  infratemporal   fossa .

27. BRANCHES Branches in middle cranial fossa Meningeal branch 2. Branches arising in pterygopalatine fossa Ganglionic branches Zygomatic nerve Posterior superior alveolar nerve 3 . Branches arising in infraorbital groove and canal Middle superior alveolar nerve Anterior superior alveolar nerve 4. Branches of infraorbital nerve in the face Inferior palpebral Lateral nasal Superior labial

28. IN MIDDLE CRANIAL FOSSA: Meningeal branch : Travels along the middle meningeal artery and provides sensory innervation to cranial dura matter .

29. IN PTERIGOPALATINE FOSSA: Ganglionic B ranches – Arises as 2trunks . Trunks join to form single root within pterygopalatine ganglion . Gives Orital branches,Palatine branches,Pharyngeal branches,Nasal branches Gives postganglionic secretomotor fibers to lacrimal gland via zygomaticotemporal and lacrimal. 2. Orbital branch : Supplies periosteum of orbit

30. Nasal branch -- Supplies to mucosa of superior and inferior conchae , posterior ethmiodal sinus and posterior portion of nasal septum. It also includes Nasopalatine branch .

31. B. . ZYGOMATIC NERVE It enters the orbit through inferior orbital fissure and runs forward along its lateral wall . Divides into 2 branches : Zygomaticotemporal nerve : emerges from the temporal surface of the bone supplies the skin over temple region . Zygomaticofacial nerve : emerges from the bone through the zygomaticofacial foramen present on the lateral surface of the bone Supplies skin of cheek

32. BRANCHES OF INFRAORBITAL NERVE ON FACE INFRAORBITAL NERVE INFERIOR PALPEBRAL Supply lower eyelid LATERAL NASAL Supply the skin on lateral side of nose SUPERIOR LABIAL Supply skin of upper lip and part of the cheek

33. Pterygopalatine G anglion Largest peripheral ganglion of parasympathetic system Topographically = maxillary nerve Functionally = greater petrosal branch of facial nerve Situation : i . Lateral to sphenopalatine foramen ii. Below the maxillary nerve . iii. Front of pterygoid canal .

34. Pterygopalatine Fossa The body of the ganglion rests in the  pterygopalatine fossa . The pterygopalatine fossa is a depression that lies within the pterygomaxillary fissure, inferior to the  sphenopalatine foramen . This fissure is a natural furrow that is formed between the posterosuperior border of the  maxilla  and the anterosuperior border of the  pterygoid plates.

35. MANDIBULAR NERVE V3 THIRD DIVISION OF TRIGEMINAL NERVE TYPE -- both  sensory and  motor . SUPPLY -- Buccal skin anterior two-thirds of the tongue, temporal region; mastication muscles, mylohyoid muscle anterior belly of the digastric muscle

36. Formed by union of two roots . Sensory root arises from lateral part of trigeminal ganglion – leaves the skull through foramen ovale . Motor root passes through foramen ovale and unites with the sensory root just below the foramen . Nerve then enters the infratemporal fossa After a short downward course, it then divides into a smaller anterior division and a large posterior division

37. BRANCHES

38. SENSORY SUPPLY OF V 3 Dura Skin Mucous membrane of lower lip, cheek and chin External ear Parotid gland TMJ Scalp over the temporal bone Lower teeth and gingiva Anterior 2/3 rd of tongue

39. MOTOR SUPPLY OF V 3 Muscles of mastication Mylohyoid Anterior belly of digastric Tensor tympani Tensor veli palatini

40. 1. Auricular branch 2. Articular branch 3. Superficial temporal nerve 4. Communicating branches

41. SUBMANDIBULAR GANGLION The  submandibular ganglion  is one of four  parasympathetic ganglia  of the head and neck. It receives parasympathetic fibers from the  facial nerve . Gross anatomy S mall ganglion suspended from the undersurface of the  lingual nerve . I nferior to  submandibular duct  sitting on the  hyoglossus muscle . S upplies secretomotor fibers to the  sublingual  and  submandibular salivary glands .

42. Preganglionic parasympathetic fibers derived from the chorda tympani travel in the lingual nerve and synapse in the submandibular ganglion. Some of the postganglionic secretory fibers enter the submandibular gland; others, by entering the lingual nerve, reach the sublingual gland. Postganglionic sympathetic fibers (from the superior cervical ganglion) pass through the submandibular ganglion and are distributed with the parasympathetic fibers . Roots Branches Lingual Nerve

43. TRIGEMINAL NERVE FRONTAL LACRIMAL NASOCILLIARY Buccal Nerve Superior alveolar nerve Middle meningeal nerve Infraorbital nerve Zygomatic nerve Auriculotemporal Nerve Pharyngeal nerve Nasopalatine nerve Inferior Alveolar Nerve Lingual Nerve RECAP

44. APPLIED ANATOMY To be able to distinguish and to cure with some degree of certainty, a disease that during the time it lasts is extremely excruciating is an addition, however small, to the utility of our profession . John Fothergill (1712–80)

45. Referred pain Mandibular neuralgia . 3. Lesion at foramen ovale . 4. Lingual nerve damage . 5. Referred pain in the ear CONTENTS

46. EXAMINATION OF TRIGEMINAL NERVE SENSORY FUNCTION MOTOR FUNCTION CORNEAL REFLEX 4. JAW JERK TEST

47. SENSORY FUNCTION Initially test the sensory branches by lightly touching the face with a piece of cotton wool followed by a blunt pin in three places on each side of the face: 1.Around the jawline 2. on the cheek 3. on the forehead 1 2 3

48. MOTOR FUNCTION Inspect for wasting of the temporal and masseter muscles . Ask patient to clench their teeth and palpate for contraction of the temporal and masseter muscles . Ask the patient then to open their mouth against resistance

49. CORNEAL REFLEX Ask the patient to look up and away, touch the cornea . Reflex blinking of both eyes is a normal response.

50. JAW JERK TEST Ask the patient to open the mouth fully, and close halfway, place index finger on the chin and tap with a patella hammer . When it is normal, tapping the mandible produces a brisk contraction.

51. M echanisms OF I njury to TRIGEMINAL NERVE Local anaesthetic injection Third molar surgery Maxillofacial trauma Orthognathic surgery Maxillofacial pathology Endodontic and chemical injury

52. LOCAL ANESTHETIC SOLUTION Incidence – between 1:26,762 and 1:160,571 Harn and Durham – 1990 – transient sensory disturbance – 3.62% Causes : Direct penetration of the nerve by needle Hematoma formation from vessel laceration Direct laceration of the nerve from a barb on the tip of needle after repeated injections . Needle contact with cortical bone . Chemical injury from intraneural injection .

53. Maxillofacial T rauma Neurosensory impairment due to trauma – 70.9 % Neurosensory alterations caused by – laceration, traction or compression of the IAN from bony segment displacement Reduction of fractures with alignment of segments and removal of loose bony segments that impinge on nerve will assist in spontaneous neurosensory recovery .

54. Orthognathic surgery During SSO, nerves could be injured at various locations Incidence of neurosensory alterations during mandibular orthognathic surgery has been found to increase with intraoperative complications . During maxillary or mid face procedures, ION is at risk for injury because of soft tissue flap retraction .

55. Maxillofacial P athology Causes – O dontogenic and non - odontogenic benign cysts and tumors .

56. Endodontic and Chemical I njury

57. CLINICAL CONSIDERATIONS Trigeminal neuralgia Herpes Zoster Ophthalmicus Trigeminal neuropathy . Wallenberg syndrome .

58. Trigeminal Neuralgia ( Fothergills Disease ) or Tic Douloreux ) Trigeminal neuralgia is defined as sudden, usually unilateral, severe, brief, stabbing, lancinating, paroxysmal, recurring pain in the distribution of one or more branches of 5 th cranial nerve . John Locke – 1677 – first full description with its treatment. Nicholas Andre – 1756 – Tic Douloureux (painful jerking) John Fothergill – 1773 – published detailed description of TN, thus , Fothergill’s disease .

59. Etiology : U nknown ; idiopathic . Dental etiology Infections – granulomatous ( sarcoidosis ) and non – granulomatous infections . Multiple sclerosis . Petrous ridge compression . Post traumatic neuralgia . Intracranial tumors . Intracranial vascular abnormalities . Viral etiology – postherpetic neuralgia .

60. GENERAL CHARACTERISTICS Incidence : rare Age : 5 th or 6 th decade Sex predilection : female predisposition (58 %) Affliction for side : right side (60 %) Trigeminal nerve involvement : V 3 >V 2 >V 1

61. Clinical Features : Refractory period can be as short as a couple of seconds With each attack, pain seems to become more intense and unbearable Pain rarely crosses midline . Pain is of short duration & lasts for a few seconds extreme cases – frozen or mask like face . different stimuli can elicit pain : Touching or applying heat or cold to the cheek or gum Chewing, yawning or talking Wind blowing on face Gustatory stimuli and vibration Smiling / brushing / shaving / washing face

62. Diagnosis – Imaging CT scan – poor resolution in posterior fossa . MRI – imaging modality of choice ; reveal MS plaques and pontine gliomas . Conventional angiogram – useful only to detect vascular malformation .

63. SWEET DIAGNOSTIC CRITERIA Pain is PAROXYSMAL Pain is provoked by light touch to the face Pain is confined to trigeminal distribution Pain is unilateral Clinical sensory examination is normal

64. MEDICAL TREATMENT First line of approach TN does not respond to analgesics Carbamazepine is used as a standard drug. Adult dose 100mg, thrice daily initially. Started as small dose & gradually increased to prevent side effects . ADVERSE EFFECTS -- include dizziness, ataxia, vertigo, skin rashes etc When carbamazepine is contraindicated, clonazepam 1.5mg/day can be used 2. Phenytoin S odium usually used in combination of carbamazepine 100mg thrice a day side effects: gum hyperplasia, swelling of lymph glands 3. Gabapentin 300mg/day used with caution in patients with renal & hepatic disease 4. Gaba agonist these drugs reduce the central projection of painful impulses eg . Baclofen , adult dose being 5-10 mg TDS .

65. Peripheral nerve injections a) Long acting anesthetic agents without adrenaline (bupivacaine) b) Alcohol block - 0.5 -2ml of 95% absolute alcohol . Peripheral neurectomy oldest and most effective Acts by interrupting the flow of afferent impulses to central trigeminal apparatus Cryotherapy or Cryoneurolysis Direct applications of cryotherapy probe at temperatures colder than -60 degrees Celsius . In this the nerve is not sectioned but destroyed 4. Peripheral radiofrequency neurolysis ( thermocoagulation ) Gregg and Small (1986) Radiofrequency electrode has the capacity to destroy the pain fibres

66. 5 Gasserian ganglion procedures Glycerol injection thermocoagulation Balloon compression 6. Open procedures (intracranial procedures ) microvascular decompression of sensory root . 1967-1976 by Jannetta most commonly performed intracranial open procedure . open craniotomy approach is used to gain access to the trigeminal root entry zone and adjacent brain stem Compressing branch of superior cerebellar artery is carefully separated from the nerve .

67. Ophthalmic zoster  is a disease characterised by reactivation of  varicella zoster virus  that is inactive in dorsal root or cranial root ganglion, after primary infection Oral and facial lesions result from HZ of 2 nd and 3 rd divisions of trigeminal nerve, but involvement of 1 st division is considerably more common esp. nasociliary nerve HZ has been associated with dental anomalies and severe scarring of facial skin when trigeminal HZ occurs during tooth formation HERPES ZOSTER O PHTHALMICUS

68. Diagnosis : history of pain. unilateral nature . Segmental distribution of lesions. vesicles are present.

69. Treatment : Acyclovir 800mg, 5 times/day for a week, within 4 days of onset of rash Valacyclovir 1,000mg, 3times/day for a week Analgesics Antibiotic ointments Systemic steroids 60mg/day Corneal grafting

70. TRIGEMINAL NEUROPATHY Characterized by numbness in the skin or mucosal membranes in the distribution of the trigeminal nerve Neuropathic weakness in the muscles of mastication . TNO should not be confused with trigeminal neuralgia (TNA ) Brief attacks of lancinating pain but without sensory impairment or motor weakness.

71. In TNO, pain may dominate the clinical picture As disorder progresses and neurons are destroyed, numbness and weakness usually appear. In untreated idiopathic TNA, neurons are preserved, although their myelin sheaths may be destroyed and there is ultimately gain of function . In TNO as the condition advances, loss of function in the affected nerve branches becomes evident .

72. Wallenberg syndrome Neurological disorder  causing a range of symptoms due to  ischemia  in the lateral part of the  medulla oblongata  in the  brainstem . The ischemia is a result of a  blockage  in the  posterior inferior cerebellar artery  or one of its branches. Wallenberg syndrome is also called Lateral medullary syndrome, posterior inferior cerebellar artery syndrome and Vertebral artery syndrome

73. CAUSE Occlusion of the  posterior inferior cerebellar artery  or one of its branches or of the  vertebral artery , in which the lateral part of the  medulla oblongata  infarcts, resulting in a typical pattern . DIAGNOSIS Diagnosis is usually done by assessing vestibular-related symptoms in order to determine where in the medulla that the infarction has occurred. Head Impulsive Nystagmus Test of Skew (HINTS) examination of oculomotor function Computed tomography (CT) Magnetic resonance imaging (MRI) to assist in stroke detection

74. Treatment involves focusing on relief of symptoms and active rehabilitation Speech Therapy  - common form of rehabilitation In more severe cases, a feeding tube maybe inserted through the mouth or a  gastrostomy  may be necessary if swallowing is impaired. Medication may be used to reduce or eliminate residual pain - anti- epileptics  such as  gabapentin . Antiplatelets like aspirin or clopidogrel and statin regimen. Warfarin is used if atrial fibrillation is present. One of the most unusual and difficult to treat - violent hiccups. struggle to eat sleep carry on conversations Unfortunately there are very few successful medications available to mediate the inconvenience of constant hiccups . Treatment for this disorder can be disconcerting because some individuals will always have residual symptoms due to the severity of the blockage as well as the location of the infarction.

75. PERIODONTAL COMPLICATIONS

76. Nerve blocks . Flap retraction during periodontal surgery . Implant surgery . Maxillary sinus surgery .

77. Photograph showing the osteology involved in an inferior alveolar nerve injection and an inset showing an actual injection .

78. Flap retraction D uring S urgery

79. Dental Implant S urgery Dent Update.  2010 Jul-Aug;37(6):350-2, 354-6, 358-60 passim

80. A = the orthopantomograph , B and C = cone beam computed tomography shows full dental implant intrusion into mandibular canal in 35 jaw dental segment region. There is direct mechanical trauma - IAN transection.

81. In a recent study, Kim et al classified the buccolingual location of IAN into 3 types : Type 1 (70%) : IAN canal follows the lingual cortical plate of the mandibular ramus and body Type 2 (15%) : IAN canal is located in the middle of the mandibular ramus posterior to the second molar. It then runs lingually to follow the lingual plate Type 3 (15%) : IAN canal is located near the middle of the ramus and body Bifid canal Nortje et al – 0.9% Grover et al – 0.08% of radiographs suggestive of bifurcation of IAN Langlais et al – 0.95% cases had bifid canals

82. Maxillary sinus surgery

83. Treatment A pproaches FACTORS DECIDING THE MOST APPROPRIATE SURGICAL APPROACH PATIENT’S ANATOMY SURGEON’S EXPERIENCE MECHANISM OF INJURY LOCATION OF INJURY

84. APPROACHES FOR DIFFERENT NERVES LINGUAL NERVE Approached intraorally via a paralingual or lingual gingival sulcus incision INFERIOR ALVEOLAR NERVE vestibular incision with identification of MN and lateral decortication to expose a portion of IAN in cases of limited mouth opening, extraoral approach applied IAN is approached via lateral decortication techniques INFRAORBITAL NERVE transorally via a maxillary vestibular incision at the time of maxillary or zygomaticomaxillary complex fracture repair

85. Outcomes of T rigeminal N erve injuries and S urgical Intervention . Injury to trigeminal nerve maybe associated with impairment of speech, taste, mastication and impact on quality of life . Based on recent studies, success of microneurosurgical reconstruction of the TN injuries could be estimated to be between 30% and 50% for all degrees of injury and types of reconstruction . Gap repair with an autogenous sural nerve graft may provide a better outcome because the graft itself provides a rich source of Schwann cells and neurotropic and neurotrophic factors that assist in the degeneration and regeneration process of neural recovery.

86. CONCLUSION Since Trigeminal nerve is a mixed nerve and supplies mainly head and neck region, one should know thoroughly about its cranial and extracranial course and distribution, to diagnose the pathologies associated with nerve and for appropriate treatment .

87. BIBLIOGRAPHY Anatomy for dental students – Inderbir Singh Grant’s Atlas of Anatomy – 10 th edition Atlas of Human Anatomy 5 th edition – Frank H. Netter The Clinical Anatomy Of Cranial Nerves – Joel A. Vilenski Anand’s Human Anatomy for dental students 2 nd edition Textbook of oral and maxillofacial surgery – Balaji 2007 edition Essentials of Human Anatomy – A.K. Datta Monheim’s Local Anaesthesia and Pain Control in Dental Practice - 7 th edition Oral and Maxillofacial Trauma – Fonseca – 4 th Edition Handbook of Local Anesthesia - Malamed

88. Inderbir Singh’s Human Embryology, 11 th edition BD Charausia , 6 th edition Textbook of anatomy, Vishram Singh, vol III, 2 nd edition Textbook of oral medicine, oral diagnosis and oral radiology – Ravikiran Ongole , 2 nd edition Burket’s oral medicine and diagnosis – 9 th edition Textbook of oral and maxillofacial surgery, Neelima Malik, 3 rd edition