Seminar on Trigeminal Nerve

1. Dr.REVATHY MOHAN
Lecturer
Malabar Dental College & Research Centre

2.  Fifth cranial nerve
 Mixed nerve
 Sensory – meninges
- skin of anterior part of head ,nasal &
oral cavities
-oral cavity (except of pharynx &base of
tongue
 Motor -musles of mastication
-mylohyoid
-anterior belly of diagastric
-tensor tympani
tensor veli palatini

3.  Sensory nuclei
from trigeminal
ganglion
3 groups:
- chief/principal
sensory nucleus
- spinal nucleus
-mesencephalic
nucleus
 Motor nucleus
lies in pons
medial to chief
sensory nucleus

4.  Trigeminal nerve is attatched to ventral aspect of
pons by two roots,a large sensory and a small motor
root
 Motor root lies ventromedial to the sensory root
 Pass forward in posterior cranial fossa towards apex
of petrous temporal bone
 Two root invaginates dura of posterior cranial fossa
below superior petrosal sinus forming trigeminal cave
 In this cave sensory root joins trigeminal ganglion
 Motor root lies deep to ganglion and doesn’t join
it,instead passes out join mandibular nerve just at its
emergence from cranial caity in foramen ovale

6.  Semilunar shape
 Location – Meckel’s cavity on anterior surface
of petrous temporal bone
 Psuedounipolar neurons
 Relations;
lateral-middle meningeal artery
medial – internal carotid artery ,cavernous
sinus
inferior –foramen lacerum,greater
petrosal nerve,motor root of trigeminal
superior- parahippocampal gyrus

8. OPHTHALMIC
MAXILLARY
MANDIBULAR

10.  First branch
 Purely sensory,smallest
 Supply
eyeball
conjunctiva
lacrimal gland
parts of mucous membrane of
nose &paranasal air sinuses
skin of forehead,eyelids,and nose
 Branches :
frontal
nasociliary
lacrimal

12.  FRONTAL
- largest branch
- passes through supra orbital superior orbital
fissure ,passes forwards above levator palpebrae
superioris
supra orbital
2
supra trochlear
Supraorbital -upper eyelid, scalp as far as
parietal bone,lambdoidal suture
Supra trochlear -conjunctiva,skin of medial aspect of
upper eyelid, skin over lower and mesial aspects of
forehead

13.  NASOCILIARY
anterior ethmoidal
2
external nasal
Anterior ethmoidal : along with posterior ethmoidal
supplies upper part of nasal cavity ,sphenoid &
ethmoidal sinus
External nasal : skin over apex and tip of nose
 LACRIMAL
supplies lacrimal gland & small area of
adjacent skin & conjunctiva

14.  Purely sensory
 From first pharyngeal arch
 Leaves cranium through foramen rotundum
 Gives off branches in 4 regions
within the cranium
in pterygopalatine fossa
in infraorbital canal
on the face

16.  WITHIN THE CRANIUM
small branch – middle meningeal nerve
sensory innervation to dura mater
 IN PTERYGOPALATINE FOSSA
zygomatic nerve
pterygopalatine nerves
posterior superior alveolar nerves

18.  ZYGOMATIC NERVE
zygomaticotemporal
zygomaticofacial
Zygomaticotemporal – skin on side of forehead
Zygomaticofacial – skin over prominence of
cheek
 PTERYGOPALATINE NERVES
orbital
nasal
palatine
pharyngeal

19.  Orbital – periosteum of orbit
 Nasal – mucous membranes of superior & middle
conchae,lining of posterior ethmoidal sinus,& posterior portion
of nasal septum
nasopalatine nerve – palatal mucosa in region of premaxilla
posterior superior lateral nasal – posterosuperior quadrant
of lateral wall of nose
 Palatine
greater palatine
lesser palatine
greater palatine – hard palate except incisor gingiva, some
parts of soft palate
lesser palatine – soft palate
 Pharyngeal – mucous membrane of nasopharynx,posterior to
auditory tube

21.  POSTEROSUPERIOR ALVEOLAR NERVES
- sensory innervation to alveoli,
periodontal ligaments ,, pulpal tissues of
maxillary molars except mesiobuccal root of
first molar

22.  IN INFRAORBITAL CANAL
middle superior alveolar nerve
anterior superior alveolar nerve
Middle superior alveolar nerve – mucosa of maxillary
sinus , premolars, mesiobuccal root of first molar ,
periodontal tissues, buccal bone , buccal gingiva
Anterior superior alveolar nerve – pulpal innervtion to
central &lateral incisors & canine,periodontal
tissues,buccal bone & mucous membrane
forms dental plexus
dental nerves
interdental branches
interradicular branches

23.  Dental nerves – pulpal innervation of all teeth
 Interdental branches – interdental pappillae &
buccal gingiva
 Interradicular branches – periodontal
ligaments of adjacent roots

24.  ON FACE
inferior palpebral
external nasal
superior labial
 Inferior palpebral – skin of lower eyelid
 External nasal – skin on lateral aspect of nose
 Superior labial – skin & mucous membrane of
upper lip

25.  Largest branch of trigeminal
 Mixed nerve
 Sensory root-
a)skin – temporal region
auricula
external auditory meatus
cheek
lower lip
chin region
b)mucous membrane – cheek
anterior 2/3rd of tongue
mastoid cells
mandibular teeth
bone of mandible
tmj
parotid gland

26.  Motor root
masticatory muscles
mylohyoid
anterior belly of diagastric
tensor tympani
tensor veli palatani
 BRANCHES
at 3 areas :
branches from undivided nerve
branches from anterior division
branches from posterior division

29.  UNDIVIDED NERVE
nervous spinosus
nerve to medial pterygoid muscle
Nervous spinosous – dura mater& mastoid cells
Nerve to medial pterygoid – tensor veli palatini& tensor
tympani
 ANTERIOR DIVISION
motor – muscles of mastication
sensory – mucous membrane of cheek,buccal
mucous membrane of mandibular molars
branches – nerve to lateral pterygoid
nerve to masseter
nerve to temporal
buccal nerve

30.  POSTERIOR DIVISION
auriculotemporal nerve
lingual nerve
mylohyoid nerve
inferior alveolar nerve

31.  Auriculotemporal nerve
communicates with facial nerve , otic
ganglion
anterior auricular branches – skin over
helix & tragus of ear
branches to external auditory meatus
articular branches to posterior portion of
temporomandibular joint
superficial temporal branches over
temporal region

32.  Lingual nerve
sensory tract to anterior two third of tongue
general sensation + gustatory
 Mylohyoid nerve
mixed nerve
motor – mylohyoid , anterior belly of diagastric
sensory – skin on inferior and anterior surface of
mental protruberance,rarely to mandibular incisors
&mesial root of mandibular first molar
 Inferior alveolar nerve
largest branch of mandibular division
incisive
mental – skin of chin ,mucous membrane of
lower lip