This document provides an overview of the trigeminal nerve (CN V), including its origins, branches, and functions. It notes that the trigeminal nerve has three main divisions - the ophthalmic, maxillary, and mandibular nerves. The cell bodies of the trigeminal nerve's sensory neurons are located in the trigeminal ganglion. The document then describes the individual branches and functions of the ophthalmic, maxillary, and mandibular nerves. It provides details on the sensory distributions and innervations of each branch.

2. PREPARED & PRESENTED BY :
SANGEETA PORIYA
DEPARTMENT OF PROSTHODONTICS

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

4.  The word ‘Trigemina’ meaning ‘Threefold’ gives the Vth 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.

5.  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

6.  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 Vth cranial nerve.
 The ganglion is Flat, Crescentric Or Semilunar in shape, measuring
1 x 2 cms with its convexity directed anterolaterally.
 Thethreedivisionsofthetrigeminalnerveemergefromthisconvexity.

7. 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.

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

9. 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

10.  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
Pons
Trigeminal Ganglion

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

12. Sensory root :
 Thelargesensoryroot(portiomajor)
arise from the Semilunar (Gasserian)
ganglion & enters the brainstem via
thesideofthePons.
 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
rootsofthetrigeminal nerve
V1
V2
V3
Sensory Distribution
of the branches of
trigeminal nerve

13. 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
mandibularnerve.Justafterleavingthetheskull,themotorrootuniteswiththe
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

14. BRANCHESOF THETRIGEMINALNERVE
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.

15. O
R
I
G
I
N
&
C
O
U
R
S
E

16. VARIOUS
BRANCHES

21. 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

22. Course:
Itleavestheanterior medial part of theganglion & passes forwardin
lateralwallofthecavernoussinus.
In the middle cranial fossa, it gives a branch, Nervus tentorii to
supplytheDura
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
threebranch’s:Lacrimal,FrontalandNasociliaryNerves.

23. 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

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

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

26. OPTHALMIC DIVISION

27. 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.

28. 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.

29. 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.

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

31. 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.

32. 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.

33. 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.

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

35. 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.

36. 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.

37. 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 :
Zygomaticnerve
Zygomaticofacialnerve
Zygomaticotemporalnerve
Pterygopalatine(sphenopalatine)nerves
Orbitalbranches
Nasalbranches
Posteriorsuperiorlateralnasalbranch’s
Medialorseptalbranches

39. MAXILLARY DIVISION

40. 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

42. 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 :

43. 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.

44. 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.

45. 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.

46. 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.

48. (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.

50. 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.

51. 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.

52. 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.

53. 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.

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

55. 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.

56. 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

57. MANDIBULAR DIVISION

58. 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

59. 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.

60. 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.

62. 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.

63. 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.

65. 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

66. 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.

67. 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.

68. Chorda Tympani nerve
Buccal nerve
Lingual nerve
Mylohyoid nerve

69. 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.

70. 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.

71. -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.

72. 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.

74. 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.

75. 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 areCongenital
cutaneous naevi as supplied by one or more division of 5th c. nerve.
(5) The motor part of the mandibular nerve is tested clinically by asking the
patient to clench hisher teeth and then feeling for the contracting
masseter and temporalis muscles on the two sides.

76. 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.

77. (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.

78.  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.
1. Pressure On Mental Foramen7:-
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

80. Precaution /Treatement:-
1. Alter the denture , so pressure does not exist
2. Trim the bone to relieve Pressure (Rare)
3. 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.

81. 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

82. 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.

83. 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.

84. 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.

85. 1. Anatomy for Surgeons by Hollinshed, Vol I, Pages : 62 – 66
2. Henry Gray, Anatomy of the Human Body, Pages : (1821–1865).
3. Sicher’s & DuBrull – Oral Anatomy, Pages : 230 – 241.
4. Malamed’s, Handbook Of Local Anesthesia, 5th Edition,Pages : 171 -
184.
5. Monheim’s – Local Anesthesia, 7th Edition, Pages : 26 – 53.
6. B.D.Chaurasia’s, Human Anatomy, Vol III, 3rd Edition, Pages : 78 –
79.
7. Boucher, Complete denture and implant supported prosthesis , 12th
Edition.Pages 108-110.
biblography.