TMJ

Question 1

Articulation of TMJ

Answer 1

mandibular condyle and mandibular fossa of temporal

Question 2

Type of joint TMJ

Answer 2

synovial, wide range of rotation and translation
2 synovial cavities

Question 3

Articular disc

Answer 3

comprised of firbocartilage
lacks blood supply/innervation
helps to maximize congruency within TMJ to reduce contact pressure

Question 4

Capsule and ligaments

Answer 4

firmer medial/lateral
looser anterior/posterior
lateral TMJ reinforces lateral side

Question 5

Type of joint TMJ

Answer 5

hinge
3 degrees of freedom

Question 6

Protrusion/Retrusion

Answer 6

mandibular condyle and disc translate anteriorly and posteriorly, relative to fossa

manible slides slightly downward during protrusion and slightly upward during retrusion

Question 7

Lateral excursion

Answer 7

primarily a side to side translation of condyle and disc within the fossa

combined with multiplanar rotations

mandibular condyle on side of lateral excursion serves as pivot point, allows for rotation

Question 8

Depression and Elevation

Answer 8

largest proportion of translation and rotation of any joint in the boyd

rotation and translation occur simultaneously, axis of rotation is always moving

Question 9

Early phase of TMJ motion

Answer 9

primarily for rotation

depression = posterior roll & anterior slide
elevation = anterior roll /posterior slide

Question 10

Late phase for TMJ motion

Answer 10

primarily translation

depression = anterior slide & posterior roll
elevation = posterior slide and anterior roll

Question 11

Masseter

Answer 11

bilarteral contraction elevates mandible
line of force nearly perpendicular to biting surface of molars

Question 12

Temporalis

Answer 12

flat, fan-shaped fills much of concavity of temporal fossa
elevate the mandible, has both ipislateral and bilateral functions

Question 13

Medial Pterygoid

Answer 13

nearly parallel with the masseter and attach on ramus
bilateral = elevation and protrusion
unilateral = excursion

Question 14

Lateral pterygoid

Answer 14

bipennate muscle
depression and protrusion (bilateral)
excursion

Question 15

Mandibular depression

Answer 15

suprahyoid muscles

Question 16

Closing the mouth

Answer 16

masseter, m. pterygoid, temporalis have good MA

Question 17

Opening the mouth

Answer 17

lateral pterygoid
suprahyoids

Question 18

TMJ disorders

Answer 18

no single mechanical or physiologic explanation

factors can include: grinding of teeth, asymmetric muscle activity, forward head posturing, CNS sensitization

most cases are self limiting, some can lead to OA

Question 19

Interventions of TMJ disorders

Answer 19

Therapeutic exercise/manual therapy
jaw splint or mouth guard
patient education
surgery

Question 20

Pathomechanics that lead to OA

Answer 20

increased joint stress
internal derangement of disc
trauma