TMJ and Hyoid

Question 1

Definition of a complex joint

Answer 1

Joint with two or more articular surfaces and a disk

Question 2

What divides the TMJ into 2 compartments?

Answer 2

Disk

Question 3

Movement(s) associated with the ventral compartment

Answer 3

1. Dorsal/ventral (Hinge)

2. Rostral/Caudal

Question 4

Movement associated with the dorsal compartment

Answer 4

Medial/lateral

Question 5

Define translation as in relates to joint movement

Answer 5

Gliding motion of a joint

Question 6

Normal movement of the TMJ in a chewing cycle

Answer 6

Figure 8 motion, as mouth opens mandible moves ventrally, caudally, and laterally

Question 7

The food stuff that gives full occlusal contact of the arcades

Answer 7

Hay is better than pellets or grain

Question 8

5 muscles of mastication

Answer 8

1. Temporalis – close
2. Masseter – close
3. Digastricus – open
4. Medial pterygoid - grind
5. Lateral pterygoid – grind

Question 9

Cranial nerves and sympathetic ganglia that are near the TMJ and hyoid apparatus

Answer 9

CN8-12

Question 10

3 things affected by TMJ dysfunction other than mastication

Answer 10

Posture
locomotion
GI function

Question 11

Effects of prematurity of strike on the TMJ

Answer 11

When there is a point on a tooth so that it contacts its opposite before the rest of the arcade, it will cause a reflex avoidance – abnormal stress on TMJ – restriction – change move disk

Question 12

Importance of a freely swinging mandible

Answer 12

Mandible needs to swing freely in order to provide the cerebellum with correct information about the position of the head in space

Question 13

Diagnosis of a rostral or a caudal restriction of the TMJ

Answer 13

1. Off set of mandible when comparing center incisors

2. Motion palpation

Question 14

Possible lesion(s) indicated when the central groove of the lower incisors are to the left

Answer 14

1. TMJ rostral on the right

2. TMJ caudal on the left

Question 15

Manipulation of a rostral or caudal TMJ restriction

Answer 15

Next to horse, hands on mandible, fingers on lateral surface, thumbs medially  gentle increasing traction ventrally, then guide lesion back to normal location

Question 16

Diagnosis of a restriction of the dorsal compartment of the TMJ

Answer 16

V-trough contact ramus of mandible just below TMJ, small palpation medially

Question 17

Manipulation of a dorsal compartment restriction

Answer 17

Same set up as motion palpation with a small HVLA

Question 18

Pain on palpation of the TMJ indicates a restriction on which side?

Answer 18

If the horse acts painfully to motion palpation of the dorsal compartment, this is the side of hypermobility. The other side is likely restricted.

Pain is usually on the side of hypermobility for the TMJ

Question 19

3 muscles that attach to the lingual process of the basihyoid

Answer 19

Sternohyoidius
omohyoidius
stylohyoid

Question 20

Clinical sign of a lingual process restriction

Answer 20

Sticking tongue out

Question 21

Relationship between hyoid restriction and TMJ restriction

Answer 21

Hyoid restriction will affect TMJ, tongue, pharynx, larynx

Question 22

Diagnosis and manipulation of hyoid restriction

Answer 22

Hyoid should move in all direction, push into resistance and hold for 20-30 seconds