Trigeminal nerve- anatomy

trigeminal nerve-origin,anatony,branches,course,applied anatomy,prosthodontic condideration

1. THE TRIGEMINAL NERVE PREPARED & PRESENTED BY : SANGEETA PORIYA DEPARTMENT OF PROSTHODONTICS

2. Introduction. Trigeminal Ganglion. Origin & Attachments of the Trigeminal Nerve Branches of the Trigeminal Nerve. Course. Branches. Innervations. Applied Anatomy. Prosthetic Relevence Summary Bibliography. CONTENTS

3. The word ‘ Trigemina’ meaning ‘ Threefold ’ gives the V th Cranial Nerve its name – The Trigeminal or Trifacial Nerve as it forms 3 divisions 1) The Opthalmic(sensory) 2) The Maxillary(sensory) & 3) The Mandibular nerve( Sensory,motor ). It is the Largest of all the Cranial Nerves , & of mixed variety having a large sensory root & a small motor root . As major general sensory nerves of face , it transmits afferent impulses from Touch , Temperature & Pain receptors. INTRODUCTION

4. Cell bodies of sensory neurons of all three divisions are located in the large Trigeminal (or Semilunar or Gasserian or Gasser's ) Ganglion. The mandibular division also contains motor fibers that innervate the muscles of mastication. Trigeminal Ganglion

5. In 1765, Anton Balthasar Raymund Hirsch , described the Gasserian ganglion, naming it in honor of his professor “Gasser’ a Professor of Anatomy at the University of Vienna. 1 It is the sensory ganglion of the V th cranial nerve. The ganglion is Flat, Crescentric Or Semilunar in shape , measuring 1 x 2 cms with its convexity directed anterolaterally . The three divisions of the trigeminal nerve emerge from this convexity. TRIGEMINAL / SEMILUNAR / GASSERIAN GANGLION 1

6. Situation & Meningeal Relations : The Ganglion lies at a depth of 4.5 – 5 cms from the lateral aspect of head, at the posterior extremity of the Zygomatic arch. It occupies a special space of dura mater, called the Trigeminal (or Meckel’s ) Cave covering the trigeminal impression on the anterior surface of the petrous temporal bone near its apex. Clinical Significance : After recovery from a primary herpes infection , the virus is not cleared from the body, but rather lies dormant in a non-replicating state within the trigeminal ganglion. Thus, herpes zoster may follow from Chickenpox.

7. Opthalmic Nerve V1 Maxillary Nerve V2 Mandibular Nerve V3 Trigeminal Nerve Trigeminal Ganglion Trigeminal Nerve in the interior of the base of the cranium

8. Trigeminal nerve in the Middle Cranial Fossa Sensory root Mouth of Trigeminal cave Trigeminal Ganglion Greater Petrosal Nerve Lesser Petrosal Nerve Mandibular Nerve V3 Maxillary Nerve V2 Opthalmic Nerve V1 Lacrimal Nerve Frontal Nerve Supraorbital nerve Supratrochlear nerve

9. The Trigeminal nerve is attached to the lateral part of the pons by its 2 roots , motor & sensory to its 4 nuclei : - Principle sensory nucleus - Mesencephalic nucleus - Motor nucleus - Spinal nucleus ORIGIN & ATTACHMENT 3 Pons Trigeminal Ganglion

10. Superficial origin of Trigeminal nerve Pons Sensory root Motor root Vagus Nerve Hypoglossal Nerve

11. Sensory root : The large sensory root ( portio major ) arise from the Semilunar (Gasserian) ganglion & enters the brainstem via the side of the Pons . The ganglion with its unipolar neurons forms Central & Peripheral processes. The peripheral branches form the opthalmic, maxillary & mandibular divisions of the nerve while the central branches are the sensory roots of the trigeminal nerve V1 V2 V3 Sensory Distribution of the branches of trigeminal nerve

12. Motor root: The small motor root ( portio minor ) arises separately from the sensory root , originating in the motor nucleus located in the upper pons and medulla oblongata. Its fibers, forming a small nerve root travels anteriorly along with, but entirely separate from, the larger sensory root to the region of trigeminal ganglion. Here the nerve passes latero-inferior direction under the ganglion towards the foramen Ovale , through which it leaves the MIDDLE CRANIAL FOSSA along the mandibular nerve. Just after leaving the the skull, the motor root unites with the sensory root of the mandibular division to form a single trunk . It supplies the following muscles : - Muscles of mastication - Mylohyoid - Ant belly of the diagastric - Tensor tympani - Tensor veli palatini

13. BRANCHES OF THE TRIGEMINAL NERVE The Trigeminal Nerve forms three divisions : 1) The Opthalmic, 2) The Maxillary & 3) The Mandibular Nerves. All of the three are chiefly sensory in nature but the mandibular division also contains motor fibres that innervate the muscles of mastication.

14. ORIGIN & COURSE SOF FR FO

15. VARIOUS BRANCHES

16. OPTHALMIC DIVISION

17. MAXILLARY NERVE

18. MANDIBULAR NERVE

19. Opthalmic Nerve (V1) Ist branch of trigeminal nerve. Sensory in nature Smallest Branch(2.5 cms long) SUPPLIES 1.Eyeball 2.Conjuctiva 3.Lacrimal GLAND 4.Parts of the mucous membrane of the nose and Paranasal Sinuses 5.Skin of the forehead eyelid and nose. Just before the ophthalmic nerve passes through the superior orbital fissure it divides into its three main branches: a. Frontal b.Lacrymal and c.Naso-cilliary nerves

20. Course: It leaves the anterior medial part of the ganglion & passes forward in lateral wall of the cavernous sinus . In the middle cranial fossa, it gives a branch, Nervus tentorii to supply the Dura It also gives off communication branches to the Oculomotor, Trochlear and Abducent cranial nerves. As the ophthalmic division passes forward from the cavernous sinus, it divides into three branch’s: Lacrimal , Frontal and Nasociliary Nerves .

21. Branches : a) Lacrimal nerve b) Frontal nerve - Supraorbital - Supratrochlear c) Nasocilliary nerve 1) Branches in the Orbit - Long root of ciliary ganglion - Long ciliary nerve - Posterior ethmoidal - Anterior ethmoidal -Internal nasal branches -External nasal branche

22. 2) Branches arising in the nasal cavity 3) Terminal branches of the opthalmic division on the face.

23. Ophthalmic division (V1) of the trigeminal nerve.

24. OPTHALMIC DIVISION

25. I) Lacrimal Nerve Smallest of the three branches. It passes into the orbit at the lateral angle of the superior orbital fissure & then courses in an anterolateral direction to reach the lacrimal gland. Innervation : a) Skin of the upper eyelid and lateral part of the eyebrow region b) Conjunctiva of the lateral part of the upper eyelid. II) Frontal nerve The largest of the three branches, & appears to be a direct continuation of the ophthalmic division.

26. It enters the orbit by way of the superior orbital fissure . At about the middle of the orbit, the frontal nerve divides into two branches: 1) Supraorbital nerve : Larger branch of the frontal nerve. It passes forward and leaves the orbit through the supraorbital foramen Innervation a) Medial part of the upper eyelid & the lower medial part of the forehead. b) Conjunctive of the upper eyelid.

27. 2) Supratrochlear nerve The smallest branch of the frontal nerve. It passes toward the upper medial angle of the orbit. Innervation : a) Skin of the Upper Eyelid and the skin of the forehead and scalp as far back as the vertex of the skull. b) Lining of the frontal sinus . III ) Nasociliary nerve It is the third main branch of the ophthalmic division. It enters the orbit through the Superior Orbital Fissure .

28. Ophthalmic division (V1) of the trigeminal nerve.

29. Its branches are divided into those arising in the orbit , in the nasal cavity , and on the face . Innervation : a. Long ciliary branch : Sensory from the eyeball and ciliary ganglion. b. Infratrochlear nerve : Upper and lower eyelid and from the side of the nose . Conjunctiva and the lacrimal sac. c. Ethmoid branches : Sensory from the lining of the frontal & sphenoid sinus and of the anterior & posterior ethmoid cells .

30. d. Internal branches : Sensory from the anterior portion of the septum and lateral walls of the nasal cavity. e. External nasal branch : Sensory from the tip of the nose. A) Branches in the orbit 5 : 1. Long root of the ciliary ganglion . The long, or sensory, root arises from the nasociliary nerve. It contains sensory fibers, which pass through the ganglion without synapsing and continue on to the eyeball by means of the short ciliary nerves. 2. Long ciliary nerves . There are usually two or three long ciliary nerves branching from the nasociliary nerve. They are distributed to the iris & cornea.

31. 3. Posterior ethmoid nerve . : It enters the posterior ethmoid canal to be distributed to the mucous membrane lining the posterior ethmoidal cells and the sphenoid sinus. 4. Anterior ethmoid nerve : It continues anteriorly along the medial wall of the orbit. In the upper part of the nasal cavity, the ethmoid nerve divides into two sets of anterior nasal branches: a) Internal nasal branches : In turn, divide in the upper anterior part of the nasal cavity into two divisions : - Medial or septal branches. - Lateral branches. b. External nasal branches : At the border between the lower edge of the nasal bone and the upper edge of the laterai nasal cartilage, the external nasal branch passes externally.

32. Ophthalmic division (V1) of the trigeminal nerve.

33. B. Branches arising in the nasal cavity The branches of the nasociliary nerve that arise in the nasal cavity supply the mucous membrane lining the cavity C. Terminal branches of the ophthalmic division on the face These branches course below the trochlear nerve to supply sensory fibers to the skin of the medial parts of both eyelids, lacrimal sac, & the lacrimal caruncle. These fibers supply the skin over the side of the bridge of nose.

34. Maxillary nerve (V2) The maxillary nerve is entirely sensory in function. Intracranial course : It originates at the middle of the semilunar ganglion & continues forward in the lower part of the cavernous sinus. Extracranial course : It then passes to the Foramen Rotundum , through which it leaves 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 .

35. Branches : In its course from the semilunar ganglion, the maxillary division gives off branches in Four Regions : 1. Branches given off in the MIDDLE CRANIAL FOSSA : Middle meningeal nerve. 2. Branches in the PTERYGOPALATINE FOSSA : Zygomatic nerve Zygomaticofacial nerve Zygomaticotemporal nerve Pterygopalatine (sphenopalatine) nerves Orbital branches Nasal branches Posterior superior lateral nasal branch’s Medial or septal branches

36. MAXILLARY DIVISION

37. Palatine branches - Greater or anterior palatine nerve - Middle palatine nerve - Posterior palatine fibres Posterior superior alveolar branches - Gingival branches - alveolar branches Branches in the Infraorbital groove & canal - Middle superior alveolar - Anterior superior alveolar nerve 3. Terminal branches of the maxillary division ON THE FACE : Inferior Palpebral branches External or Lateral nasal branches Superior Labial Branches

38. I) Branches given off in the middle cranial fossa : In the middle cranial fossa a small branch, the middle meningeal nerve , passes with the middle meningeal artery and its branches to supply the dura with sensory fibers. Innervation : It sends a sensory branch to the dura. II) Branches in the pterygopalatine fossa : A) Zygomatic nerve The zygomatic nerve leaves the 2nd division in the pterygopalatine fossa and passes anteriorly and laterally through the inferior orbital fissure into the orbit. Here it divides into two parts :

39. 1. Zygomaticofacial nerve - It passes forward on the lateral orbital foramen. The nerve pierces the orbicularis oculi muscle. Innervation : Sensory from the skin over the zygomatic bone. 2. Zygomaticotemporal nerve - It leaves the orbit between the great wing of the sphenoid and the zygomatic bone to enter the temporal fossa. Innervation : Sensory from the skin of the side of the forehead and of the anterior part of the temporal region. B. Pterygopalatine (sphenopalatine) nerves : They are two short nerve trunks that unite at the pterygopalatine ganglion and are then redistributed into several branches.

40. The branches of distribution of the pterygopalatine nerves are divided into three groups : 1) Orbital branches : Two or three fine filaments enter the orbit by means of the inferior orbital fissure Sensory from the periosteum of the or & from the lining of the sphenoid sinus and posterior ethmoid cells. 2) Nasal branches. In the nasal cavity, it divides into the i) Posterior superior lateral nasal branches : These branches transmit sensory impulses from the mucous membrane of the nasal septum and posterior ethmoid cells.

41. ii) Medial or septal branch : It transmits sensory impulses from the mucous membrane over the vomer & then descends in the incisal canal and ramifies in the mucous membrane of the premaxillary region of the hard palate. 3)Palatine branches : These descends in the pterygopalatine canal, where the fibers usually divide into three strands : a) Greater or anterior palatine nerve : This nerve emerges on the hard palate by passing through the greater palatine foramen and courses in an anterior direction between the osseous hard palate & mucoperiosteum It breaks up into numerous branches in its course and finally extends as far forward as the premaxillary palatine mucosa.

42. It is sensory from the mucous membrane of the major part of the hard palate and adjacent part of the soft palate. b. Middle palatine nerve : Emerges from the lesser palatine foramen. Mucous membrane of the soft palate. c. Posterior palatine fibers : Emerging from the lesser palatine foramen. Mucous membrane of the soft palate and tonsil area. (4) Nasopalatine branches - Mucous membrane of the lower and posterior part of the nasal septum and from the Premaxillary part of the hard palate.

43. (5) Pharyngeal branch - Sensory from the mucous membrane of the naso pharynx and the area behind the auditory tube. C. Posterior superior alveolar branches : Two or three branches leave the maxillary division just before it enters the inferior orbital fissure. They pass downward and continue on the posterior surface of the maxilla. An internal branch of the posterior superior alveolar nerve goes along with a branch of the internal maxillary artery through the posterior superior alveolar canal, which opens on the posterior surface of the maxilla. In the bone, the nerve passes down the posterior or posterolateral wall of the maxillary sinus.

44. Innervation : Gingival branches - Buccal gingiva of the upper molar region & Mucous membrane of part of the cheek. Alveolar branches - Maxillary molars, except the mesiobuccal root of the upper first molar and their Gingivae , Mucous membrane of the maxillary sinus. D. Branches in the infraorbital groove and canal The nerve in the infraorbital groove and canal is known as the infraorbital nerve. From this groove several fibers leave the infraorbital nerve and descend.

45. 1) Middle superior alveolar nerve : It br’s within the mucous membrane of the maxillary sinus to join with other alveolar nerves in forming the superior dental plexus of nerves. Innervation : Sensory from the maxillary bicuspids and the mesiobuccal root of the first molar sensory from the lining of the maxillary sinus.

46. 2) Anterior superior alveolar nerve : It descends from the infraorbital nerve just inside the infraorbital foramen in the anterior part of the infraorbital canal & descend in fine canals in the maxilla Innervation : Sensory from the maxillary incisors and cuspid & from the lining of the maxillary sinus. E. Terminal branches of the maxillary division on the face As the infraorbital nerve is about to emerge from the infraorbital foramen on the front of the maxilla, it divides into three terminal nerve branches: the Inferior palpebral , External or lateral nasal, and Superior labial branches.

47. Innervation : 1) Inferior palpebral branches : skin of the lower eyelid and its conjunctiva. 2) External or lateral nasal branches : skin of the side of the nose. 3) Superior labial branches skin and mucous membrane of the upper lip.

48. Cutaneous Branches of Trigeminal Nerve on the Face Infratrochlear nerve Supratrochlear nerve Supraorbital nerve Lacrimal nerve Zygomaticofacial nerve Infraorbital nerve Mental nerve

49. Mandibular nerve (V3) The mandibular division of the trigeminal nerve is the largest of the three divisions. It is formed by the union of the large sensory (afferent) bundle of fibers and a small motor (efferent) bundle of fibers. Intracranial Course : The motor root is located in the middle cranial fossa. It joins the sensory root after the latter leaves the semilunar ganglion. The two roots pass side by side in the dura of the middle cranial fossa to the foramen ovale . Extracranial course : Leaving the foramen ovale , the two roots unite to form a short single trunk.

50. Branches : The mandibular division may be divided into two groups: 1) Branches from the undivided nerve Nervus spinosus Nerve to internal pterygoid muscle 2) Branches from the divided nerve Anterior division Pterygoid nerve Masseter nerve Nerves to the Temporal Muscle Anterior deep temporal nerve Posterior deep temporal nerve Buccal nerve

51. MANDIBULAR DIVISION

52. Posterior division Auriculotemporal nerve Communication of the auricotemporal nerve -Communicating branches of postganglionic sympathetic fibers. -Communicating branches to the facial nerve. Branches of the auriculotemporal nerve Parotid branches Articular branches Auricular branches Mental branches Terminal branches Lingual nerve Communications with Chorda tympani nerve Inferior Alveolar nerve . Mylohyoid nerve

53. I. Branches from the undivided nerve : A. Nervus spinosus The nervus spinosus arises outside the skull and then passes into the middle cranial fossa to supply the dura and the mastoid cells . B. Nerve to internal pteryigoid muscle A branch of the motor root passes to innervation the internal pterygoid muscle . This branch passes without interruption to innervate the tensor veli palatini and the tensor tympani muscles . II. Branches from the divided nerve : Below the level of the undivided part of the mandibular division, the trunk separates into two parts: anterior and posterior divisions .

54. A. Anterior division The anterior division is smaller than the posterior division. It passes downward and forward, where it divides: Branch to External pterygoid muscle Branch to Masseter muscle Branches to Temporal muscles Anterior deep temporal nerve Posterior deep temporal nerve Buccal (Long buccal) nerve 1. Pterygoid Nerve : The pterygoid nerve enters the medial side of the external pterygoid muscle to provide its motor nerve supply.

55. 2. Massetter nerve : The masseter nerve passes above the external pterygoid to traverse the mandibular notch and enter the deep side of the masseter muscle. 3. Nerves to the temporal muscle : a. Anterior deep temporal nerve - This nerve passes upward and crosses the infratemporal crest of the sphenoid bone. It ends in the deep part of the anterior portion of the temporal muscle. b. Posterior deep temporal nerve - This nerve passes upward to the deep part of the temporal muscle. 4. Buccal nerve : Usually the buccal nerve passes downward, anteriorly and laterally between the two heads of the external pterygoid muscle.

56. At about the level of the occlusal plane of the mandibular second and third molars, it divides into several branches that ramify on the buccinator muscle. Innervation : Sensory from the mucous membrane and the skin of the cheek region; sensory from buccal gingivae of the mandibular molar region.

57. B. Posterior division : The larger posterior division is mainly sensory but also carries some motor components. This division extends downward and medially and then branches into the auriculotemporal, the lingual, & the inferior alveolar nerves. 1) Auriculotemporal nerve : The united nerve passes posteriorly, deep to the external pterygoid muscle, and then between the sphenomandibular ligament and the neck of the condyle of the mandible

58. Divides into numerous branches : The parotid, Articular, Auricular, Mental, and Terminal branches. Innervation : a) Skin over the areas supplied by the branches of the facial nerve, that is, zygomatic, buccal, and mandibular areas. b) Parotid gland by means of the parotid branch. c) Temporomandibular articulation. d) Skin lining the external auditory meatus and from the lateral surface of the tympanic membrane. e) Skin and scalp over the upper part of the external ear and the side of the head up to the vertex of the skull.

59. 2. Lingual nerve : The lingual nerve is the smaller of the two terminal branches of the posterior division of the mandibular nerve. At first it passes medially to the External Pterygoid Muscle and, as it descends, lies between the INTERNAL PTERYGOID MUSCLE and the ramus of the mandible in the pterygomandibular space.

60. Chorda Tympani nerve Buccal nerve Lingual nerve Mylohyoid nerve

61. Innervation : 1.Membrane covering the anterior two thirds of the tongue; 2.Mucous membrane of the floor of the mouth and of the lingual side of the mandibular gingivae; 3.Submandibular and sublingual glands and their ducts.

62. The lingual nerve conveys special sense of taste from the anterior two thirds of the tongue . It also contains secretomotor fibers to the submandibular and sublingual salivary glands and the mucous glands in the floor of the mouth. 3. Inferior alveolar nerve : Passes downward on the medial side of the external pterygoid muscle and the medial side of the mandibular ramus . On the medial side of the ramus in the pterygomandibular space, it enters the mandibular foramen.

63. -Within the mandible it descends in the inferior alveolar canal and is distributed throughout the body of the mandible. -In the inferior alveolar canal it gives off branches to the mandibular teeth as apical fibers that enter the apical foramina of the lower teeth to supply the dental pulps. -As the inferior alveolar nerve reaches the region of the mental foramen, it divides into TWO TERMINAL BRANCHES . -The MENTAL NERVE leaves the body of the mandible through the mental foramen. The remaining fibers, the INCISIVE BRANCH , continue anteriorly within the body of the mandible and form a fine incisive plexus that supplies the cuspid tooth and the incisor teeth.

64. Before the inferior alveolar nerve enters the mandibular foramen it gives off a branch, the MYLOHYOID branch, which contains sensory and motor fibers . The mylohyoid nerve continues downward and forward in the mylohyoid groove. a. Dental branches - Sensory from all of the lower molar and bicuspid (mandibular) teeth and their periodontal membranes. b. Mental nerve - Sensory from the skin of the lower lip and chin regions and from the mucous membrane lining the lower lip region. c. Incisive nerve - Sensory from incisors, cuspid teeth, & their periodontal membranes.

65. Sensory disturbances in the distribution of the trigeminal nerve are common after facial injuries leading to stretching or compression of nerve (1) Trigeminal neuralgia may involve one or more of the three divisions of the trigeminal nerve . It causes attacks of very severe flikring and scalding pain along thedistribution of the affected nerve. Pain is relieved either by : (a) Injecting 90% alcohol into the affected division of the nerve (b) By sectioning the affected nerve, the main sensory root or the spinal tract of the trigeminal nerve which is situated superficially in the medulla called as Medullary Tractotomy . APPLIED ANATOMY

66. 2) Damage to the nasociliary branch can produce loss of the protective corneal reflex with serious consequences to the eye. 3) Damage to the auriculortemporal nerve in the region of the neck of the mandibular condyle - Von Frey's Syndrome (facial flushing and sweating instead of salivatory response at meal times) T/t : By roll on deperspirant ( Drichlor ) or alternatively by nerve section. (4) on the face (port wine strains) map out accurately the are Congenital cutaneous naevi as supplied by one or more division of 5 th c. nerve. ( 5) The motor part of the mandibular nerve is tested clinically by asking the patient to clench his\her teeth and then feeling for the contracting masseter and temporalis muscles on the two sides.

67. If one Masseter is paralysed, the jaw deviates to the paralysed side , on opening the mouth by the action of normal lateral Pterygoid of the Opposite side. The activity of the Pterygoid muscle is tested by asking the patient to move the chin from side to side. ( 7) Lingual nerve lies in contact with the mandible, medial to the third molar tooth. In extraction of malposed "wisdom tooth" care must be taken not to injure the lingual nerve. (8) Post-herpetic neuralgia. This unfortunate sequela occurs most frequently in elderly patients as a result of scarring of nerve.

68. (9) Trotter's syndrome - Carcinoma of the nasopharynx often producing trigeminal neuralgia like pain in the mandible, tongue & side of the head along with the middle ear deafness. (10) Wallenberg syndrome : Also called the lateral medullary syndrome a stroke causes loss of pain / temperature sensation from one side of the face and the other side of the body.

69. A Prosthodontist should be thorough with the course and area of supply of the trigeminal nerve especially mandibular and maxilllary division,so in order to tackle any significant problem related to it. Pressure On Mental Foramen 7 :- If bone resorption in mandible has been extreme The mental foramen may open near or directly at the crest of the residual bony process When this happens, the bony margins of the mental foramen usually are dense and resilient to resorption than the anterior or posterior to foramen This causes the margins of the mental foramen to extend and have sharp edges 2-3 mm higher than the surrounding bone Pressure from the denture against the mental nerve exiting the foramen causes Pain . Also ,pressure against the sharp bone will cause pain as it is pinched between the sharp bony margin of the mental foramen Prosthetic relevence

70. Precaution / Treatement :- Alter the denture , so pressure does not exist Trim the bone to relieve Pressure (Rare) Increasing the opening of the mental foramen downwards towards the inferior border of the body of the mandible ,therefore this cahnge permits the nerve to exit the bone at a point lower than the previous situation.This takes pressure off.

71. 2. Pressure over the incisive papilla:- lies immediately behind and between the central incisors, Lies nearer to the crest of the residual ridge as resorption progresses. This papilla houses a foramen named as incisive foramen , Nasopalatine Nerve And Vessels pass through the foramen. Treatement /precaution:- Denture should be relieved in this area

72. 3. Trigeminal nerve Palsy/Paralysis Clinical sign and symptoms includes:- a. Reduced mouth opening on the affected side. b.Hyeractivity of muscle on the affected side. c.Loss of corneal reflex on the affected side. Etc… So one should always consider a different technique for impression for e.g. Sectional tray technique.

73. 1.The fifth cranial nerve which is the trigeminal nerve consists greater somatic sensory and small somatic motor portion. 2.Its motor fibers supply the Masticatory Muscles that is Masseter, Temporalis ,Lateral and Medial Pterygoid muscles. The motor fibers of this nerve also supply the Tensor Palati muscle, Mylohyoid Muscle, Anterior Belly of Digastric muscle, Tensor Tympani muscle. 3.The sensory fibers of this nerve supply the skin of the entire face and mucus membrane of the cranial viscera with exception of the pharynx and the base of the tongue. CONCLUSION

74. 4.The first of three divisions passes through the superior orbital Fissure, the second through the foramen Rotundum and the third which joined by the entire Somatized visceral motor portion , through the foramen Ovale . 5.A Prosthodontist should be thorough with the course and area of supply of the trigeminal nerve especially, so in order to tackle any significant problem related to it.

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