Trigeminal nerve

TRIGEMINAL NERVE. ( ANATOMY & CLINICAL IMPLICATIOND)

1. TRIGEMINAL NERVE MODERATOR : Dr Gaurav PRESENTED BY: Dr Md Mahbubul Hoda

2. CONTENTS INTRODUCTION TRIGEMINAL NERVE EMBRYOLOGY TRIGEMINAL GANGLION DIVISIONS BRANCHES GANGLIONS ASSOCIATED APPLIED ANATOMY REFERENCES

3. TRIGEMINAL NERVE The name TRIGEMINAL was given by “WINSLOW” It is the fifth cranial nerve. It is the largest and one of the most complex cranial nerves. It consists of two roots : a) sensory b) motor

4. The sensory component supplies the skin of the entire face and the mucous membrane of the cranial viscera, except for the pharynx and the base of the tongue The motor component supplies the muscles of mastication (masseter, temporalis, lateral pterygoid and medial pterygoid ), muscle of ear (tensor tympani), muscle of soft palate (tensor veli palatini ), mylohoid muscle and anterior belly of digastric.

5. EMBRYOLOGY The Trigeminal nerve arises from nuclei located in the brain stem. The sensory nucleus arises from metencephalon and myelencephalon but are later displaced partially in mesencephalon. The motor nucleus arise from metencephalon and stays there.

6. The Trigeminal nerve is related to four nucleus: 1.Mesencephalic nucleus 2.Main Sensory nucleus 3.Spinal nucleus 4.Motor nucleus

7. The sensory trigeminal nerve nuclei are the largest of the cranial nerve nuclei and extend through whole of the brainstem. The nucleus is divided in three parts: Mesencephalic trigeminal nucleus Principal pontine nucleus Spinal nucleus of trigeminal nerve

8. The mesencephalic nucleus is involved with proprioception. Neurons of this nucleus cells receiving proprioceptive information from the jaw and send projections to the trigeminal nucleus to mediate jaw reflexes. The principal pontine nucleus receives information about discriminative sensation and light touch of the face. The spinal nucleus of trigeminal nerve receives information about touch, pain, temperature and vibration.

9. PATHWAY The sensory root of trigeminal root enters into the trigeminal nuclei The trigeminal tract enter into the ventral posterior medial nucleus of thalamus. These fibres which go upward and enter into the thalamus is known as TRIGEMINAL LEMINISCUS or TRIGEMINO THALAMIC TRACT.

10. TRIGEMINAL GANGLION Trigeminal ganglion is also known as semilunar ganglion or gasserian ganglion and is cresentric in shape. It is convex anterolaterally and concave posteromedially . It lies in posterior most part of middle cranial fossa ( M eckel’s cave or cavum trigeminale ). It lies in a bony fossa at the apex of petrous part of temporal bone on the floor of middle cranial fossa just lateral to posterior part of lateral wall of cavernous sinus

11. DIVISION It has three division :- a) V1 - Ophthalmic division b) V2 - Maxillary division c) V3 - Mandibular division The ophthalmic division enters orbital cavity through superior orbital fissure. The maxillary division exits from cranial cavity through foramen rotundum . The mandibular division passes through foramen ovale .

12. The trigeminal ganglion arises from sensory root which is connected to lateral part of mid pons of brain The motor root also comes from lateral part of mid pons of brain and leaves cranial cavity with mandibular division through foramen ovale .

13. BRANCHES

14. OPHTHALMIC NERVE The ophthalmic nerve or first division of the trigeminal is a sensory nerve. It is the smallest of the 3 divisions of trigeminal nerve. It arises from the anteromedial part of trigeminal ganglion. Its about 2.5cm in length and passes forward along the lateral wall of cavernous sinus, below the occulomotor and trochlear nerve

15. Finally it enters the orbit through superior orbital fissure and divides into three branches 1. Lacrimal 2. Frontal 3. Nasociliary

16. I) LACRIMAL NERVE II) FRONTAL NERVE A. Supraorbital nerve. B. Supratrochlear nerve. III) NASOCILIARY NERVE A. Branches in the orbit 1. Short ciliary nerves. 2. Long ciliary nerves. 3. Posterior ethmoid nerve. 4. Anterior ethmoid nerve. a) Internal nasal branches b) External nasal branches B. Branches arising in the nasal cavity C. Terminal branches of the ophthalmic division on the face

17. LACRIMAL NERVE It is the smallest branch of ophthalmic division. Enter the orbit through lateral part of superior orbital fissure. Runs in anterior direction with the lacrimal artery. Enters the lacrimal gland, supplying it and the adjoining conjunctiva and then pierces the orbital septum and end in the upper eyelid.

18. FRONTAL NERVE Largest branch of ophthalmic. Enters the orbit - superior orbital fissure and runs forward between the Levator palpebrae superioris and the periosteum. Midway between the apex and base of the orbit it divides into two branches: 1. Supratrochlear Nerve 2. Supraorbital nerve

19. SUPRATROCHLEAR NERVE Smaller of the two - passes above the superior Oblique muscle and gives off a descending filament to join the infratrochlear branch of the nasociliary nerve. Escapes from the orbit between the superior oblique and the supraorbital foramen. Supplies - skin of the lower part of the forehead close to the middle line and sends filament to the conjunctiva and skin of the upper eyelid.

20. SUPRAORBITAL NERVE Proceeds between the levator palpebral superioris and the orbital roof and traverses the supra orbital foramen Then it ascends up to the forehead and ends in two branches : the medial branch and the lateral branch. It supply the skin of the upper eyelid and lower medial portion of the forehead.

21. NASOCILIARY NERVE It originates from ophthalmic nerve in the anterior part of cavernous sinus . It e nters the orbit through superior orbital fissure. Branches of the nasociliary nerve are divided into those: 1.Branches in the orbit. 2.Branches in the nasal cavity 3.Branches on the face

22. BRANCHES IN ORBIT 1. Short ciliary nerve . pass through the ganglion without synapsing. continue to the eyeball. 2. Long ciliary nerve . -branches are 2-3 in Nos. -iris and cornea. 3. Posterior ethmoid nerve . This nerve enters the posterior ethmoidal canal. Supply to ethmoidal & sphenoidal sinuses. 4. Anterior ethmoid nerve . supply the frontal sinus. divides into internal and external nasal branches. Internal nasal:-septal branch and lateral branch. External nasal:- ala of nose and tip of nose.

23. BRANCHES IN NASAL CAVITY Supplies the mucous membrane lining the cavity. BRANCHES ON FACE S kin of medial parts of both eyelids, the lacrimal sac and lacrimal caruncle and side of bridge of nose

24. APPLIED ANATOMY Superior orbital fissure syndrome Ophthalmoplegia Pupillary constriction Enopthalmos Ptosis of eyelid

25. MAXILLARY NERVE It is the second division of trigeminal nerve. It is a purely sensory nerve. It is intermediate both in position and size between the ophthalmic and mandibular nerve. It originates from the middle of the semilunar ganglion and continues forward in the lateral part of cavernous sinus, it then passes through the foramen rotundum .

26. Through which it takes the cranial fossa and enters the pterygopalatine fossa . It enters the inferior orbital fissure to pass into the orbital cavity, here it turns laterally in a groove on the orbital surface of the maxilla called the infraorbital groove, continues forwards, the second division emerges on the anterior surface of the maxilla through the infraorbital where it divides. It then divides into branches which spread out upon the side of the nose, lower eyelid and the upper lip.

27. BRANCHES OF MAXILLARY NERVE It is divided into four groups, as they are given off: 1. Middle Cranial Fossa 2. Pterygopalatine Fossa 3. I nfraorbital Canal and Groove 4. On the Face

28. MIDDLE CRANIUM FOSSA MIDDLE MENINGEAL NERVE PTERYGOPALATINE FOSSA ZYGOMATIC SPHENOPLATINE POSTERIOR SUPERIOR ALVEOLAR INFRAORBITAL CANAL ANTERIOR SUPERIOR ALVEOLAR MIDDLE SUPERIOR ALVEOLAR ON THE FACE INFERIOR PALPERBAL EXTERNAL NASAL SUPERIOR LABIAL

29. 1) BRANCHES GIVEN OFF IN THE MIDDLE CRANIAL FOSSA 1. Middle Meningeal nerve 2) BRANCHES IN THE PTERYGOPALATINE FOSSA A. ZYGOMATIC NERVE 1. Zygomaticofacial nerve 2. Zygomaticotemporal nerve B. PETERYGOPALATINE (SPHENOPALATINE) NERVES 1. Orbital Branches (from Inferior orbital fissure) 2. Nasal branches a) Posterior superior lateral nasal branches b) Medial or septal branches 3. Palatine branches a) Greater or anterior palatine nerve b) Middle palatine nerve. c) Posterior palatine fibers. 4. Pharyngeal branch C. POSTERIOR SUPERIOR ALVEOLAR BRANCHES

30. 3 ) BRANCHES IN THE INFRAORBITAL GROOVE AND CANAL 1 . Middle superior alveolar nerve . 2 . Anterior superior alveolar nerve. 4) BRANCHES ON THE FACE 1. Inferior palpebral branches 2. L ateral nasal branches 3. Superior labial branches

31. A. Zygomaticotemporal B. Zygomaticofacial C. Post. Sup. Alveolar Branch D. Nasopalatine E. Greater Palatine F. Lesser Palatine G. Mid. & Ant. Alveolar Branch H. Infraorbital

32. MIDDLE MENINGEAL NERVE: It is given off from the maxillary nerve directly after its origin from the semilunar ganglion. It accompanies the middle meningeal artery and supplies the dura mater. ZYGOMATIC NERVE: It arises from pterygopalatine fossa. Enters the orbit through inferior orbital fissure and then divides into two branches 1.Zygomaticotemporal 2.Zygomaticofacial

33. ZYGOMATICO-TEMPORAL BRANCH : It runs along the lateral wall of the orbit in a groove in the zygomatic bone. It receives communication from the lacrimal and passing through a foramen in the Zygomatic bone it enters the temporal fossa. Ascends between the bone and substance of the Temporalis muscle and pierces the temporal fascia about 2.5 cm above the Zygomatic arch and then get distributed to the skin of the side of the forehead and communicates with the facial nerve

34. ZYGOMATICO-FACIAL BRANCH: Passes along the inferio -lateral angle of the orbit. Emerges from the face through a foramen in the Zygomatic bone. Perforating the Orbicularis oculi it supplies to the skin on the prominence of the cheek. SPHENOPALATINE BRANCHES: Two in number. Descend to the sphenopalatine ganglion.

35. These nerves are then distributed into 1 . Orbital branches 2 . Nasal branches posterior superior lateral nasal branch medial or septal branch 3 . Palatine branches greater palatine nerve middle palatine nerve posterior palatine nerve 4 . Pharyngeal branches

36. ORBITAL BRANCH: Two or three delicate filaments which enter the orbit by the inferior orbital fissure and supply the periosteum NASAL BRANCH POSTERIOR SUPERIOR LATERAL NASAL BRANCHES: Distributed to the septum and lateral wall of the nasal fossa. It enters the posterior part of the nasal cavity by the sphenopalatine foramen It supply the mucous membrane covering the superior and middle nasal conchae, the lining of the posterior ethmoidal cells and the posterior part of the septum

37. MEDIAL OR SEPTAL BRANCH It supplies the posterior part of roof and septum. One of the nerve which is longer and larger than others is known as NASOPALATINE NERVE It enters the nasal cavity through sphenopalatine foramen to reach the septum and then descends to the roof of the mouth through the incisive canal where it communicates with the corresponding nerve of the opposite side and with the anterior palatine nerve.

38. PALATINE NERVES : Distributed to the roof of the mouth, soft palate, tonsil, and lining membrane of the nasal cavity. Most of their fibers are derived from sphenopalatine branches of the maxillary nerve. They are three in number : a) Greater palatine b) Middle palatine c) posterior palatine

39. GREATER PALATINE NERVE This nerve emerges on the hard palate by passing through greater palatine foramen and courses in an anterior direction between the osseous hard palate and mucoperiosteum to supply the major part of hard palate and palatine gingiva It extends as far as forward as the premaxillary palatine mucosa which is also supplied by terminal branches of nasopalatine nerve

40. MIDDLE PALATINE NERVE: Emerges through one of the minor palatine canals and distributes branches to the uvula, tonsil, and soft palate POSTERIOR PALATINE NERVES: Descends through pterygopalatine canal and emerges by a separate opening behind the greater palatine foramen. It supplies to the soft palate, tonsil, and uvula.

41. PHARYNGEAL NERVE : It is a small branch arising from the posterior part of the ganglion. It passes through the pharyngeal canal with the pharyngeal branch of the internal maxillary artery and then get distributed to the mucous membrane of the nasal part of the pharynx, behind the auditory tube

42. POSTERIOR SUPERIOR ALVEOLAR NERVE : It arises from the trunk of the nerve just before it enters the infraorbital groove . Descends into the tuberosity of the maxilla and then give off several twigs to the gums and mucous membrane of the cheek. Then it enters the posterior alveolar canals on the infratemporal surface of the maxilla and communicate with the middle superior alveolar nerve and give off branches to the lining membrane of the maxillary sinus and three twigs to each molar tooth

43. MIDDLE SUPERIOR ALVEOLAR NERVE : It is given off from the nerve in the posterior part of the infraorbital canal. It runs and forward in a canal and enter the lateral wall of the maxillary sinus to supply the two premolar teeth. It forms the superior dental plexus with the anterior and posterior superior alveolar branches. ANTERIOR SUPERIOR ALVEOLAR NERVE : It is given off from the nerve just before its exits from the infraorbital foramen. It descends in a canal in the anterior wall of the maxillary sinus and divides into branches which supply the incisor and canine teeth.

44. It then communicates with middle superior alveolar branch and gives off a nasal branch which passes through a minute canal in the lateral wall of the inferior meatus. It supplies the Mucous membrane of the anterior part of the inferior meatus and floor of the nasal cavity. INFERIOR PALPEBRAL BRANCH : It ascends behind the Orbicularis oculi. It supplies the skin and conjunctiva of the lower eyelid. Join at the lateral angle of the orbit with the facial and zygomaticofacial nerves.

45. EXTERNAL NASAL BRANCHES : It supplies the skin of the side of the nose and join with the terminal twigs of the nasociliary nerve. SUPERIOR LABIAL BRANCHES : The largest and most numerous. It descends behind the Quadratus labii superioris . Distributed over the skin of the upper lip, the mucous membrane of the mouth and labial glands. They are joined immediately beneath the orbit, by filaments from the facial nerve forming with them the infraorbital plexus.

46. MANDIBULAR NERVE It is largest of all three divisions of trigeminal nerve. It is derived from 1 st brachial arch. Mixed nerve Made of two roots : sensory and motor

47. A large sensory root proceeding from the semilunar ganglion. A small motor root which passes beneath the ganglion and unites with the sensory root just after its exit from foramen ovale . Immediately beneath the base of the skull it gives off a recurrent branch ( nervus spinosus ) and the nerve to the Pterygoideus internus and then divides into two trunks - an anterior and a posterior.

48. Trunk remains undivided for 2-3mm. Then it divides into small anterior and large posterior division. Branches given off are:- 1. Undivided Nerve 2. Anterior division 3. Posterior division

49. BRANCHES 1.UNDIVIDED NERVE/TRUNK Nervous spinosis Nerve to medial Pterygoid 2. DIVIDED NERVE a) Anterior Division Masseteric Nerve Deep temporal Nerve Nerve to lateral Pterygoid Buccal Nerve/ Buccinator b) Post . Division Auriculotemporal Lingual Nerve Inferior Alveolar Nerve

50. NERVOUS SPINOSUM It’s also called as Meningeal nerve. It re-enters the cranium through the foramen spinosum a long with the middle m eningeal artery to supply the dura mater and mastoid air cells. It divides into two branches, anterior and posterior branch. P osterior branch supplies the mucous lining of the mastoid cells. The anterior communicates with the meningeal branch of the maxillary nerve

51. NERVE TO MEDIAL PTERYGIOD It supplies to medial pterygoid muscle. It also gives of small branches to tensor veli palatini and tensor tympani through otic ganglion without interruption.

52. ANTERIOR DIVISION The anterior division is smaller than the posterior division. It runs forward under lateral pterygoid muscle and give branches :- Masseteric Nerve Deep temporal Nerve Nerve to lateral Pterygoid Buccal Nerve/ Buccinator

53. MASSETERIC NERVE I t emerges at the upper border of the lateral pterygoid just infront of the TMJ, passes laterally through the mandibular notch and enters the deep surface of the masseter muscle. it also supplies the TMJ. DEEP TEMPORAL NERVE It ascend deep to lateral pterygoid and supply temporalis muscle. NERVE TO LATERAL PTERYGOID It enters the medial side of the lateral pterygoid muscle to provide its motor nerve supply

54. BUCCAL NERVE It passes downward anteriorly & laterally between the two heads of the external pterygoid muscle. At about the level of the occlusal plane of the mandibular 2 nd & 3 rd molars, it divides into several branches that divide on the buccinator muscle. It does not supply the buccinator muscle. It supplies the skin of cheek and buccal gingiva of mandibular molars and mucobuccal fold

55. POSTERIOR DIVISION It is m ainly sensory but also carries motor fibres . It descends downward and medially to lateral pterygoid muscle and branches into AURICULOTEMPORAL NERVE LINGUAL NERVE INFERIOR ALVEOLAR NERVE

56. AURICULOTEMPORAL NERVE It arises from 2 roots which encircle the middle meningeal artery The trunk passes posterior to lateral pterygoid between the neck of mandible and sphenomandibular ligament superior to 1 st part of maxillary artery It lies behind the TMJ close to the parotid Ascends behind superficial temporal vessels and then in temporal region divides into superficial temporal branches

57. COMMUNICATION 2 roots of the nerve:- both these roots receive communications from the OTIC ganglion. And receive postganglionic secretomotor fibres for the parotid gland they control the secretions from the gland. Communicating branches to the facial nerve: These are purely sensory from the Auriculotemporal nerve.

58. BRANCHES 1. Parotid branches - sensory , secretomotor , vasomotor. 2. Articular branches - to the TMJ. 3. Auricular branches - to the skin of the auricle & tragus. 4. Meatal branches - Meatus of the tympanic membrane 5. Terminal branches - Scalp over the temporal region 

59. LINGUAL NERVE It originates f rom the posterior trunk of mandibular nerve in the infratemporal fossa . It is the smallest of the two terminal branches. It supplies mucous membrane of the anterior two-thirds of the tongue, floor of the mouth, tonsil and gum.

60. It lies anterior to inferior alveolar and between lateral pterygoid and tensor palatini which receives through chorda tympani It then emerges from inferior border of lateral pterygoid to lie between ramus and medial pterygoid Between origins of superior constrictor and mylohyoid it reaches the side of the tongue below and behind 3 rd molar It lies just below mucous membrane in lateral lingual sulcus, proceeds anteriorly looping downward and medial to submandibular duct to deep surface of submandibular gland

61. COMMUNICATION As the lingual nerve passes medially to the lateral pterygoid , it is joined from behind by the chorda tympani. This nerve conveys secretory fibres from the facial nerve . The parasympathetic secretory fibres control the submandibular & sublingual salivary glands.

62. INFERIOR ALVEOLAR NERVE It is the largest branch of the posterior division. It passes downward on the medial side of the external pterygoid muscle & passes between sphenomandibular ligament and ramus of mandible upto mandibular foramen It then enters the mandibular canal and runs below the teeth as for as mental foramen and terminates by dividing into branches.

63. Branches of the inferior alveolar nerve are the Mylohyoid Dental Incisive Mental .

64. MYLOHYOID NERVE: Derived - inferior alveolar just before it enters the mandibular foramen. It descends - groove on the deep surface of the ramus of the mandible - reaching the under surface of the Mylohyoid - supplies this muscle and the anterior belly of the Digastric . DENTAL BRANCHES: Supply - molar and premolar teeth Above the alveolar nerve they form an inferior dental plexus.

65. INCISIVE BRANCH: Continued onward within the bone and supplies the canine and incisor teeth. MENTAL NERVE: Emerges at the mental foramen and divides beneath the Triangularis muscle into three branches. 1.One descends to the skin of the chin. 2.Two ascend to the skin and mucous membrane of the lower lip .

66. GANGLIONS CILIARY GANGLION: Parasympathetic Ganglion placed in a course of the occulomotor nerve. It lies in the apex of orbit between the optic nerve and tendon of the lateral rectus muscle. It has sensory, motor, and sympathetic roots. sensory - from nasociliary motor - from occulomotor , preganglionic fibres from Edinger westphal nucleus to supply sphincter pupillae and ciliaris muscle. sympathetic - from post ganglionic fibres of superior cervical ganglion to supply the blood vessels of eye ball and dilator pupillae

67. PTERYGOPALATINE GANGLION: Largest parasympathetic ganglion Connected to maxillary nerve in infratemporal fossa Sensory to periosteum of the orbit, orbicularis and nasal cavity,maxillary sinus , palate , nasopharynx. Topographically related to maxillary nerve, but functionally related facial nerve The preganglionic fibres are from superior salivatory nucleus

68. OTIC GANGLION: Topographically related to mandibular nerve, but functionally is a part of glossopharyngeal nerve Situated in infratemporal fossa below the foramen ovale and surrounds the origin of nerve to medial pterygoid . Preganglionic parasympathetic fibres from inferior salivatory nucleus to reach the ganglion

69. SUBMANDIBULAR GANGLION: Topographically related to lingual nerve, functionally it is connected to the facial nerve It is a relay station for secretomotor fibres to the submandibular and sublingual glands. The preganglionic fibres are from superior salivatory nucleus

70. APPLIED ANATOMY Trigeminal neuralgia or tic douloreux is described as the most excruciating pain. This intense, stabbing, electric shock-like pain is caused by irritation of the trigeminal nerve Anticonvulsive medications are normally the first treatment choice. Initially short, mild attacks, but trigeminal neuralgia can progress,causing longer, more frequent bouts of searing pain . They may also be provoked by even mild stimulation of face

71. PRECIPITATING FACTORS: Shaving Stroking your face Eating Drinking Brushing your teeth Talking Putting on makeup Encountering a breeze Smiling

72. Treatment- Medical: carbamazepine( Tegretol ), phenytoin, valproate . SURGERY : Alcohol injection Glycerol injection OR Percutaneous Glycerol Rhizotomy (PGR) Balloon compression. Also called as percutaneous balloon compression of the trigeminal nerve (PBCTN) Electric current. Also called as percutaneous stereotactic radiofrequency thermal rhizotomy (PSRTR) Microvascular Decompression (MVD ) Severing the nerve. A procedure called Partial Sensory Rhizotomy (PSR) Radiation. GAMMA-KNIFE RADIOSURGERY (GKR)

73. SPHENOPALATINE NEURALGIA ETIOLOGY vasodilatation of the internal maxillary artery near the region of Sphenopalatine region. Unilateral paroxysms of intersperse pain in the region of eyes,maxilla , ear,mastoid base of the nose and beneath the zygoma There are no TRIGGER ZONES Seen in persons below 40 years Treatment - Alcohol injection of the ganglion - Resection of the ganglion

74. AURICULOTEMPORAL SYNDROME ETIOLOGY It results from damage to the Auriculotemporal nerve. The usually syndrome follows some surgical operation CLINICAL FEATURES Flushing and sweating of the involved side of the face TREATMENT Intracranial division of Auriculotemporal nerve

75. CROCODILE TEARS Exhibits profuse lacrimation during eating especially hot or spicy food..It follows facial paralysis Or as a result of herpes zoster ,head injury or intra cranial operative trauma TREATMENT- Intracranial division of Auriculotemporal nerve

76. COMPLEX REGION PAIN SYNDROME Is a burning pain and paresthesia associated with deformation of nerves Seen after surgical tooth extraction TREATMENT Injection of procaine ,alcohol Surgical curettage of bone or Resection of nerves

77. REFERENCES GRAY’S ANATOMY BY HENRY GRAY HUMAN ANATOMY BY BD CHAURASIA HUMAN EMBRYOLOGY BY I.B SINGH LOCAL ANESTHESIA BY STANLEY F. MALAMED LOCAL ANESTHESIA AND PAIN CONTROL IN DENTAL PRACTICE BY MONHEIM’S

78. CUNNIGHAM’S MANUAL OF PRACTICAL ANATOMY

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