TMJ

Question 1

Dental Occlusion

Answer 1

How teeth fit together

Question 2

Describe the diarticular synovial TMJ

Answer 2

Upper joint: Between articular eminence and disk
Lower joint: Between condyle and disk
Disk is attached to and travels with condyle
*Disk is thicker in the back

Question 3

Articular capsule of TMJ

Answer 3

Lax anteriorly and posteriorly
Reinforced laterally
Inferiorly contributes to collateral ligaments

Question 4

Collateral ligaments of TMJ

Answer 4

Reinforcement of inferior capsule
Hold disk to condyle
Must be torn for displacement of disk

Question 5

Lateral ligaments of TMJ

Answer 5

Run at various angles, from zygomatic process to condyle
Lateral Tempro-mandibular ligament: Inner horizontal and outer oblique fibers
Primary reinforcing ligament
Stabilizes lateral joint

Question 6

Accessory ligaments of TMJ

Answer 6

Sphenomandibular and Stylomandibular
- Minor suspensory role
Mandibular-Malleolar
- Tinitis?

Question 7

Movement of the condyles during (R) lateral excursion

Answer 7

R condyle spins

L condyle drops and translates

Question 8

TMJ Depression

Answer 8

Early phase (1/3): Lower joint rolling
Late phase (2/3): Upper joint gliding forward (along with disk)

Question 9

Lateral Pterygoid function

Answer 9

Assists anterior glide of disk

Question 10

Disk Displacement with reduction (DDWR)

Answer 10

Patient symptoms:
- Joint noise during mandibular opening and closing
- Two “pops” or “clicks” (one on opening, one on closing)
Disk in out of place when mouth is closed, slips into place upon full opening

Question 11

Disk Displacement without reduction (DDWoR)

Answer 11

Acute
-Depression: Opening limited to ~20 mm, deflection toward ipsilateral side
- Protrusion: Limited, deflection toward ipsilateral side
May feel just one pop
Disk doesn’t pop into place when mouth opens – it restricts the opening

Question 12

Temporalis

Answer 12

From temporal fossa to coranoid process
Elevation, Retrusion, Ipsilateral excursion of mandible
Refers pain to teeth

Question 13

Masseter

Answer 13

Superficial and deep components from zygomatic arch to ramus of mandible
- Adhesions can form between superficial and deep
Elevation, Retrusion, Ipsilateral excursion of mandible (powerful)

Question 14

Medial/Internal Pterygoid

Answer 14

From pterygoid plate of sphenoid to medial ramus of mandible
Elevation, Protrusion, Contralateral Excursion of mandible
Forms a sling with masseter for powerful elevation

Question 15

Lateral/External Pterygoid

Answer 15

Two heads from pterygoid plate of sphenoid to neck of mandible, articular disk, and capsule of TMJ
Protrusion, Contralateral Excursion of Mandibler
-Pierces the medial pterygoid

Question 16

Supra-hyoid Muscles - Depressors

Answer 16

Digastric, stylohyoid, geniohyoid, mylohyoid

Question 17

Digastric

Answer 17

From mastoid and lower mandible to hyoid (through sling on hyoid)
Primary depressor and retrusion

Question 18

Stylohyoid

Answer 18

From styloid process to hyoid

Depression of mandible

Question 19

Geniohyoid

Answer 19

From symphysis of mandible to hyoid

Depression of mandible

Question 20

Mylohyoid

Answer 20

From floor of mandible to hyoid

Depression of mandible

Question 21

Infrahyoid Muscles

Answer 21

Sternohyoid, thyrohyoid, omohyoid

Stabilize hyoid to facilitate manidbular depression

Question 22

Maximal Rest Position

Answer 22

Desirable position of mandiblewith minimal tonus of jaw musculature and no occlusion of teeth

Question 23

Freeway Space (Interocclusal Clearance)

Answer 23

Space between teeth at rest

Question 24

Postural Position

Answer 24

Rest position of the tongue

Anterior-superior tip of tongue on hard palate behind incisors

Question 25

TMJ relation with FHP

Answer 25

Infrahyoid muscles stretched
Mandible retruded and depressed
Suprahyoid shortened