Tempormandibular Joint

Question 1

Resting Position

Answer 1

• mouth closed with teeth slightly apart

- condyle of mandible resting in mandibular fossa

Question 2

Anatomical Considerations

Answer 2

• mandibular fossa of temporal bone acts as relatively shallow socket
• condyle of mandible articulates with socket when in resting position
• articular disc: superior and inferior articular cavities-contoured to fit along articular surfaces when jaw closed

Question 3

Motions of Jaw

Answer 3

• depression and elevation occur in inferior compartment
• protrusion and retrusion occur at superior articular cavity
• lateral movement
• hinge: elevation (flexion) and depression (extension)
• articular disc: superior and inferior articular cavities

Question 4

Movement Analysis

Answer 4

• upper cavity: temporal bone and superior disc-gliding/translatory movement
• lower cavity: inferior disc and mandibular condyle-rotary or hinge
• bilateral action of TMJ

Question 5

Depression

Answer 5

• lower cavity: mandibular condyles roll onto inferior surface of disc
• upper cavity: mandibular condyle and disc translates along mandibular fossa of temporal bone-articular eminence

Question 6

Normal ROM

Answer 6

• opening: roughly 2-3 finger widths
• extreme opening: repeated occurrence can cause trauma to the disc
• bilateral and coordinated movement of both condyles
• prime movers: masseter, temporalis, medial and lateral pterygoid mm

Question 7

Elevation

Answer 7

• temporalis
• masseter
• medial pterygoid (bilateral)

Question 8

Depression

Answer 8

• lateral pterygoid (primary)
• suprahyoid (assists)
• infrahyoid (assists)
• gravity
• reminder: condyles translate forward along articular disc while forward rotation is occuring

Question 9

Mandibular Depression

Answer 9

• central incisors: tips of lateral right or left maxillary and mandibular; measure distance with ruler
• therabite ROM scale

Question 10

Protrusion

Answer 10

• lateral and medial pterygoids
• pt slightly opens (de-occlude)
• tips of right or left maxillary and mandibular central incisors
• measure distance past tips of maxillary central incisors

Question 11

Retrusion

Answer 11

• temporalis
• masseter (assists)
• not measured

Question 12

Lateral Movements

Answer 12

• medial pterygoid (contralateral)
• de-occlude teeth
• space between central incisors (max and mind) are reference
• central mark on ruler=0
• final measure (distance from assigned 0)

Question 13

Symptoms of TMJ

Answer 13

• radiating pain in face, jaw, neck (headaches)
• if have headaches ask what time of day
• jaw muscle stiffness
• limited movement or locking of jaw
• painful clicking, popping, or grating in jaw joint when opening or closing mouth
• change in way upper and lower teeth fit together.