TMJ Flashcards
What are tempomandibular disorders characterized by?
1) Pain in pre auricular area, TMJ, or muscles of mastication
2) limitations/deviations in mandibular ROM
3) TMJ sounds during jaw function
What is the spectrum of symptoms for TMJ?
signs of symptoms: clicking, deviation, fatigue but no pain and no disability
OR
Severe pain with severe disability
What is onset of TMJ pain?
Acute: eating, impact jaw, dental procedures, yawning
Insidious onset repetitive trauma
What is tipping point for insidious onset?
Gradual progression of symptoms over time leading to pain
Clenching, bruxing, postural imbalance are forms of micro trauma
Have history of cervical whiplash injury (flex/ext type)
What is mechanism of TMJ pain?
Repetitive stress due to Restriction, compensation, and behaviors
1) restrictions: joint, soft tissue
2) Poorly controlled motion: muscle imbalance, poor quality of mvmt or sequencing, dental occlusion and loss/change in teeth
3) behaviors: posturing, grinding/clenching, fear avoidance behaviors/pain beliefs
What are the 5 potential pain generators?
1) Inflammation of ligaments/capsule: due to clenching/grinding from malocclusion
2) Internal derangement of ligament or disc: torn ligament that tethers the articular disc
3) Joint arthritis: result of disc tear and subsequent displacement overtime the joint surface breaks down
4) muscles: over pull or under pull leading to pain
5) Sensitization (central)
What is the disc in TMJ?
Dense fibrocartilage disc divides joint into a superior and inferior cavity filled with synovial fluid to lubricate joint
What happens in superior and inferior cavity of TMJ?
Superior: mandibular fossa and superior aspect of disc, translation occurs here
Inferior cavity: inferior aspect of disc and mandibular condyle, condyle rotation occurs here
What are 3 articular regions of the disc?
Anterior and posterior divisions have neural innervations and vascular supply
Intermediate portion is most dense, avascular, and aneural and gets nutrition from synovial fluid
What attaches to different portions of the disc?
Anterior: attaches to anterior capsule and superior head of lateral pterygoid
Medial and lateral: attaches to condylar head via the medial and lateral collateral ligaments
What are the ligaments of the TMJ?
Temporormandibular ligament (lateral ligament): limits posterior displacement during jaw opening
Collateral ligaments: resist excessive medial/lateral displacement of disc
Accessory ligaments: suspending mandible and preventing excessive protrusion
What is progression of joint noise?
Reciprocal clicks: loud click on opening is disc reduction, click on closing is disc dislocation
Once disc is fully displaced anteriorly and completely w/o reduction there will be no audible sound (leading to OA)
Single sound can be condyle touching disc or articular surface during opening or closing
What are stages of disc displacement?
Anterior disc displacement with reduction: reciprocal clicks
Anterior disc displacement without reduction: clicks have stopped, limited opening range and referred to as “closed lock”
Posterior disc displacement: cant close mouth “open lock”, can occur after prolonged dental procedures when lateral pterygoid becomes overstretched
What are normal ranges for depression/elevation of mandible?
Elevation (closing): teeth approximation
Depression (opening): maximum 40-50 mm= 4 fingers; functional range 35 mm= 3 fingers
What are kinematics of depression?
Rotation of condyle dominates first 25 mm
Condyle translation dominates 25-35 mm
What are normal ranges for protrusion/retrusion?
Protrusion: 6-9 mm; mandible and disc translate anterior and inferior
Retrusion: 3 mm; mandible and disc translate posterior
What is range for lateral deviation and kinematics?
1/4 of opening range
Rotation/spinning ipsilateral condyle and horizontal translation of the contralateral condyle
What does muscle imbalance mean to you?
imbalances of forces, muscle still strong but inefficient
What muscles have different roles?
yes. mobilizers, stabilizers, power
How does pain change muscle function?
if muscle stops working the pain inhibition will keep going
What happens to muscle if it’s chronically used in shortened position?
in mid range it will be strong