tm joint, mandibular nerve

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

THANK YOU