tm joint, mandibular nerve
TRANSCRIPT
TEMPORO-MANDIBULAR JOINT, MANDIBULAR NERVE AND
BRANCHES, OTIC GANGLION
DR PRATIK MISTRY
TEMPORO-MANDIBULAR JOINT
INTRODUCTION
Type of joint Articular surface Above: Below:
Atypical synovial joint
Articular surface covered with fibro-cartilage
Complex joint Articular disc divide
completely into upper menisco-mandibular and lower menisco-temporal compartment.
LIGAMENTS Capsular ligament with synovial
membrane Articular disc Lateral ligament Accessory ligaments
CAPSULAR LIGAMENT WITH SYNOVIAL MEMBRANE
Attachments Above, below and in
front Synovial membrane
lines inner aspect in both compartments.
ARTTICULAR DISC Oval plate of fibro-
cartilage divide the joint Represent degenerated
primitive insertion of lateral pterygoid
Attachments: Posteriorly, splits into
upper and lower lamella which are attached to squamo-tympanic fissure and neck of mandible
Structurally, consists of 5 parts:
1. Anterior extension2. Anterior thick band3. Intermediate zone4. Posterior thick band5. Bilamellar region
LATERAL LIGAMENT OF T.M JOINT Blends with lateral
part of capsule Attached above to
the tubercle of root of zygoma to below lateral aspect of neck
ACCESSORY LIGAMENTS
Spheno-mandibular ligament
Stylo-mandibular ligament
RELATIONS In front
Lateral pterygoid Temporalis Masseteric vessels and
nerve Behind
External acoustic meatus
Parotid gland Auriculo temporal n Superficial temporal
vessels
Laterally subcutaneous
Medially Lateral pterygoid Roots of auriculo
temporal nerve enclosing medial meningeal artery
Spine of sphenoid and sphenomandibular lig
Chorda tympani n. Above
Floor of middle cranial fossa
BLOOD SUPPLY NERVE SUPPLY
Branches of superficial temporal and maxillary arteries
Auriculo-temporal nerve Masseteric nerve
MOVEMENTS AND MECHANISM Movements
are: Protrusion Retraction Depression Elevation Side to side
chewing movements
MECHANISM OF MOVEMENTS Menisco-temporal
(upper) compartment permit gliding movement in protrusion, retraction and in chewing
Menisco-mandibular (lower) compartment permit rotation around two axis:
1. Transverse axis for depression and elevation
2. Vertical axis for side to side movements
MUSCLES PRODUCING MOVEMENTS
MECHANISM OF DEPRESSION Three phase
Rotatory Rolling (gliding) Rotatory
Initial phase:- transverse axis remain fix
Next phase:- transverse axis move forward
Final phase:- transverse axis remain fix
FACTORS MAINTAINING STABILITY BONES: Articular tubercle Post glenoid
tubercle
LIGAMENTS: Lateral ligament of
T.M. joint
MUSCLES: Protrusion –
temporalis Retraction – lat.
Pterygoid
CLINICAL ANATOMY
Forward dislocation Clicking and pain
due to degeneration or displacement of disc
Referred pains
MANDIBULAR NERVE AND ITS BRANCHES
INTRODUCTION Largest of all 3 divisions Nerve of 1st arch Mixed nerve with large
sensory and small motor root Both roots emerge from pons
& emerge through foramen ovale and unite to form trunk.
Bet. tensor veli palatini & lateral pterygoid. Otic ganglion sandwiched between trunk of nerve and tensor muscle and lie in front of middle meningeal artery.
Divide into small anterior and large posterior divisions.
BRANCHES From the trunk
Meningeal branch Nerve to medial
pterygoid From the anterior division
Buccal nerve (sensory) Motor branches:
masseteric nerve, deep temporal nerves and nerve to the lateral Pterygoid
From the posterior division Auriculotemporal nerve Lingual Inferior alveolar nerve
FROM THE TRUNK Meningeal branch
(nervous spinosus) Nerve to medial
pterygoid. Also supply tensor tympany and tensor veli palatini muscles.
FROM ANTERIOR DIVISION 3 motor and 1
sensory Masseteric nerve Deep temporal
nerves Nerve to lateral
pterygoid Buccal nerve
FROM POSTERIOR DIVISION 3 sensory branches Auriculo-temporal
nerve Inferior alveolar
nerve which carry few motor fibres to supply mylohyoid and anterior belly of digastric as nerve to mylohyoid
Lingual nerve
CHORDA TYMPANI NERVE
Branch of facial nerve which convey preganglionic secretomotor fibres to submandibular and sublingual glands and carry taste sensations from anterior 2/3 of tongue
Origin and course
OTIC GANGLION Small, oval parasympathetic ganglion,
2-3 mm in size, reddish grey in colour situated in the infratemporal fossa
Topographically connected to mandibular nerve but functionally related to glossopharyngeal nerve.
SITUATION Below foramen
ovale Medial to trunk of
mandibular nerve, lateral to tensor veli palatini
In front of middle meningeal artery
CONNECTIONS Parasympathetic
or secretomotor root
Form by lesser petrosal nerve
Sympathetic root
Derived from plexus around middle meningeal artery, pass ganglion without relay
BRANCHES Post ganglionic
parasympathetic fibres join auriculo-temporal nerve
Post ganglionic sympathetic fibres pass without relay join auriculo-temporal nerve
Fibres from nerve to medial pterygoid to supply tensor tympany and tensor veli palatini
APPLIED ANATOMY Trigeminal neuralgia-
pain along the branches sensory root divided to
relieve pain Mandibular nerve block During removal of
wisdom teeth, avoid injury to lingual nerve
Referred pain to ear while teeth pain
Inferior alveolar nerve block for removal of teeth of lower jaw
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