TMD [Guest Lecture] Flashcards
Define temporomandibular disorders (TMD)
Characterized by
- pain in the preauricular area, TMJ, or mm of mastication
- limitations/deviations in mandibular ROM
- TMJ sounds during jaw function
Describe the range of TMD sx
Clicking, deviation, fatigue w/o pain and distability to severe pain with severe disability
Describe the causes of repitive stress in TMD
Restriction (joint/soft tissue)
Compensation (mm imbalance, poor sequencing)
Behavior (posture, grinding, clenching)
Describe the role of teeth in TMD
Teeth control and decelerate motion
Loss of teeth increased PROM and decreased the amount of control over jaw motion
List the potential pain generators in TMD
- Inflammation of the ligaments/capsule
- Internal derangement of ligament or disc
- Joint arthritis
- Muscles (imbalance, over/under pull can cause mm pain)
- Central sensitization
Structure: Where translation occurs
Superior TMJ Cavity
Structure: Where rotation occurs
Inferior TMJ Cavity
Structure: portion of disc containg the superior head of the lateral pterygoid
Anterior portion of disc
Structure: Portion of disc that attached to the condylar head via medial and lateral collateral ligaments
Medial and lateral disc
Structure: limited posterior displacement during jaw opening
Temporomandibular or lateral ligament
Structure: resists excessive medial/lateral displacement of disc
Collateral ligaments
Structure: suspending mandible and preventing excessive protrusion
accessory ligaments (stylomandibular and sphenomandibular)
Movement: Loud click on opening
Disc reduction
Movement: Smaller click on closing
Disc dislocation
Term: clicking with opening or closing of the jaw
reciprocal clicks
Condition: no audible sound with full anterior displacement w/o reduction
Locked joint
Condition: Presents with reciprocal clicks
Anterior disc displacement WITH reduction
Condition
- Hx of reciprocal clicks that have now stopped
- Often have limited opening range or “closed lock”
Anterior disc displacement WITHOUT reduction
Condition:
- Unable to close mouth or “open lock”
- Rare but can occur after prolonged dental procedures
- Lateral pterygoid becomes overstretched
Posterior disc displacement
Describe the kinematics of jaw depression/opening
The first 25 mm of motion is accomplished by ROTATION
The second 25-35 mm of motion is accompished by TRANSLATION
Describe the kinematics of protrusion and retrusion
Pro = anterior and inferior disc translation
Re = posterior disc translation
Describe the kinematics of lateral deviation
Rotation and horizontal translation of the contralateral condyle
Describe the goal for lengthened mm in regards to posture control
You don’t need to change the length (won’t be able to shorten it) or stregnth, rather you need to SHIFT the length tension curve to a functional range so it can be more efficient in the inner range
Muscle:
Bilateral = elevation
Bilateral superficial fibers = protrustion
Bilateral deep fibers = retraction
Unilateral = ipsilateral deviation
Masseter
Muscle:
Bilateral = elevation and retraction
Unilateral = ipsilateral lateral deviation
Temporalis
Muscle:
Bilateral = elevation and protrustion
Unilateral = contralateral lateral deviation
Medial Pterygoid
Muscle:
Bilateral = protrusion
Unilateral = contralateral lateral deviation
Lateral Pterygoid
Muscle: depression of the mandible during mouth opening
Inferior head of lateral pterygoid
Muscle: contracts eccentriclaly during mouth closing to monitor disc position and avoid displacement
superior head of lateral pterygoid
Muscle: responsible for swallowing
Hyoid muscles
Muscle: Important for speech, swallowing, and tongue movement
Infrahyoid muscles
List the Ideal Exercise Prescription for TMJ
- Postural control exercises for the kinetic chain
- Low threshold postural training
- Work on improving movement patterns
- Work on isometrics to recruit slow motor units
- Stretching
