Temporomandibular Joints Flashcards Preview

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Flashcards in Temporomandibular Joints Deck (31):

What is the glenoid fossa

Base of skull
Where head of condyle articulates the temporal bone


What is the anterior margin of the TMJ

Articular tubercle which prevents TMJ dislocating Anteriorly


What is a typical joint

2 bones lined with hyaline cartilage
Articular surfaces lined with hyaline cartilage
Non-articular surface lined with synovial mem which nourishes , reduces friction, cools the joint, remove waste

Has a capsule to enclose the joint and retain fluid
Ligaments to strengthen the joint
Skeletal ,us les move joint


What is a unique synovial joint

Articular surfaces all fibrous tissue
Temporal bone covered in periosteum
Intra articular disc made of dense fibrous tissue
Head of mandibular condyle covered in perichondrium


What is the lingula

At opening of mandibular foramen
Passing down through foramen is the inferior alveolar nerve form Vc

Links formed by powerful ligament attachment of sphenomandibular ligament


What is the retro molar triangle

Area of bone depression
After 3rd molar
Imp for pterygomandibular raphe


What su the pterygoid fovea

Lateral pterygoid muscle attachment
Muscle of mastication


What is the transverse crest of the condyle head

Angulation dividing condylar head into posterior and anterior condylar facets


What is the head of the condyle like

Tilted Anteriorly
Flattened A-P
Elongated latero-medially
Long axis points Posteriorly


What does the lateral temporomansibular ligament do

Prevent dislocation Posteriorly


What does the joint capsule do

Attaches around circumferences of articular surfaces


What are the attachment points of stylomandibulad ligament

Styloid process to medial aspect of angle of mandible


What is the stylomandibulad ligament a specialisation of

Deep cervical fascia - investing layer


What is the sphenomandibular ligament

Remains meckels cartilage
From spine of sphenoid to lingula on mandible


What are the attachments of the pterygomandibular raphe

Pterygoid hamulus to retro molar triangle ( Buccinator origin)


What does the intra articular disc do with the joint capsule

Merge with joint capsule around its circumference ensuring separation of joint into 2 discrete spaces upper and lower spaces


What does the intra articular disc do for movement of TMJ

Provides stability of joint during movement by improving 'fit' between the bony articulating surfaces


What is the intra articular disc made up of

Dense fibrous connective tissue


How many zones are associated in he intra articular disc

5 zones


What is the anterior extension of the intra articular disc

Continuous with joint capsule Anteriorly and with tendon of lateral pterygoid muscle


What is the posterior extension of the intr articular disc

Upper layer - elastic fibres assist disc returning to rest
Both layers - vascular tissue which engirge with blood on opening and empties into pterygoid venous plexus on closing


What are the final 3 layers of the intra articular disc

3 bands in disc proper
Anterior thick
Intermediate thin
Posterior thick


What are the two joint cavities

Upper and lower joint spaces formed by intra articular spaces


What happens in initial opening for the TMJ

Anterior rotation of head of condyle
Movement occurs in lower joint space
Disc remains in place


What happens when the jaw opens fully to dislocation to the TMJ

After initial anterior rotation of condyle head in lower joint space
Disc then translates slides Anteriorly articulating with mandibular fossa and articular eminence
Movement occurs in upper joint space


What is the name for jaw wide open

Internal derangement with reduction


What is the movement of TMJ when jaw open

Depression bilateral and symmetrical
Initial anterior rotation hinge lower joint space
Anterior translation slide upper joint space


What is the movement of TMJ for jaw closing

Elevation bilateral and symmetrical
Initial posterior translation upper joint space
Subsequent posterior rotation lower joint space


What are the movements of the TMJ in a lateral movement

Bilateral and asymmetrical
Working side - lateral rotation
Non-working side - anterior and medial rotation


What is the movement of TMJ in protrusion and regression

Mandible can pull forward relative to maxilla protrusion
Mandible pull back relative to maxilla retrusiin


What kind of joint is the TMJ