TMJ Flashcards
What are the main 4 structural componenets of the TMJ
- Squamous portion of temporal
- Condylar head of mandible
- Articular disc
- Within TMJ
- Ligaments
- Serve as boundaries
TMJ Joint Classification
Movement and portion of joint
- Ginglymoarthroidal joint
- Gliding (sliding)
- Translational movement
- Proteusion/Protraction
- Retrusion/ retraction
- Upper part of joint
- Hinge
- Rotational movement
- Elevation and depression
- Lower part of joint
- Gliding (sliding)
- Diarthrotic joint
- Capable of free movement
What is the mandibular (glenoid) fossa covered with
And whats its distribution
- Avascular fibrocartilage (instead of hyaline cartilage)
- Thickest in load bearing areas
- Squamous portion
- Disc
- Condyle
Relations of Squamous and TMJ
Ant
- Anterior
- Articular eminence become articular tubercle
- Attachment for the capsule and lateral (temporomandibular) ligament
- Articular eminence become articular tubercle
Relation of Squamous and TMJ
Int
- Intermediate
- Glenoid (madibular) fossa
- Depression for condyle
- Thin layer of compact bone
- Glenoid (madibular) fossa
Relation of Squamous and TMJ
Post
- Posterior
- Petrotympanic (squamotympanic) fissure
- Tympanic plate tappering into postglenoid tubercle
- Attachment for capsule and retrodiscal pad
What do the condyle articulate with
What is the articulating surface covered with
Where is the main load bearing
They articulate with the articular disc
Articular surface covered in Avascular fibrous CT
Lateral aspect is the main load bearing side
What type of bone the condylar
Measurements
- Cancellous (spongy) bone covere by a thin layer of compact bone
- Medilateral 20mm
- Anteroposterior 10 mm
Articular Disc
Composed of
Located
- AKA Meniscus
- Composed of dense fibrous CT
- Located btw squamous portion of temporal bone and condyle
- Attaches to capsule
Anterior Band of Articular Disc
- Medium thickness
- Anterior to condyle with mouth closed
Intermediate band of articular disc
- Thinest
- Along the articular eminence with mouth closed
Posterior band of Articular Disc
- Thickest portion of disc
- Superior to condyle with mouth closed
- Attached to bilaminar zone including retrodiscal pad
Medial/Lateral attachment of articular disc
Strong medial/lateral collateral ligaments
Attach disc to Condyle
Anterior attachment of articular disc
Disc attached to capsule and Superior head of lateral pterygoid
Superior attachment of articular disc
Disc is contiguous with bilaminar zone, blends with capsule
Bilaminar Zone
Poaterior to articular disc
Highly distortable
Divided into Sueprior lamina, Retrodiscal pad, Inferior lamina
Superior lamina of bilaminar zone
- Elastic fibers
- Anchors superior aspect of posterior disc to the capsule and to bone, postglenoid tubercle and tympanic plate
Retrodiscal pad of bilaminar zone
- Sits postereior to condyle
- Highly vascular and neural part of TMJ
- Collagen elastic fibers, fat, nerves, blood vessels
Inferior lamina of bilaminar disc
- Collagen fibers
- Anchors inferior of posterior disc to capsule
TMJ Compartments
Articular disc divides TMJ into superior and inferior compartments
Lined with synovial membranes
Superior Compartment of TMJ
Location and movement
- Between squamous and srticular disc
- Sliding, translation
Inferior compartment
Location and movement
Between articular disc and condyle
Hinge, rotation
Fibrous (joint) capsule or Capsular Ligament
Completely encloses articular surface of temporal bone and condyle
Many sensory receptors
Outer fibrous layer
Inner synovial layer
Outer fibrous layer of Capsular ligament
Fibrous connective tissue
Toughned along medial and lateral aspects by ligaments
