5 TMJ

Question 1

arcs of opening

Answer 1

1st arc: rotation

2nd arc: translation

Question 2

ginglymoid and arthodial joint

Answer 2

ginglymoid = rotation/hinging
arthodial = translation, gliding

Question 3

mandibular condyle dimensions

Answer 3

greater mediolateral dimension than anteroposterior

Question 4

mandibular condyle poles

Answer 4

medial pole is More prominent
lateral pole is Less prominent
intersect at anterior portion of f. magnum
extend medially and posteriorly

Question 5

mandibular condyle articular surface

Answer 5

posterior surface has larger articular surface

Question 6

articular (glenoid) fossa and eminence

Answer 6

of zygomatic arch of temporal bone
eminence = functioning
fossa = nonfunctioning, ant. to dividing petrytympanic fissure
mandibular fossa = large depression behind articular fossa

Question 7

innervation

Answer 7

trigeminal CN V mandibular branch (III)

masseteric, Auriculotemporal, deep temporal

Question 8

irrigation of TMJ

Answer 8

superficial temporal a.
internal maxillary a.
middle meningeal a.

Question 9

colateral/discal ligament attachments

Answer 9

two short ligaments: medial/distal pole –> disc

Question 10

colateral/discal ligament functions

Answer 10

maintain disc and mandibular condyle

prevent excessive rotation

Question 11

capsular ligament/fibrous capsule attachments

Answer 11

superiorly to temporal bone around border of articular surfaces of mandibular fossa and articular eminence –> inferiorly to neck on condyle

Question 12

capsular ligament/fibrous capsule functions

Answer 12

surrounds TMJ
keeps articular surfaces in contact
temporal and mandibular fossa remain in contact
produce synovial fluid

Question 13

lateral ligament OOP attachments

Answer 13

outer oblique portion

lateral surfaces of zygomatic arch and articular eminence –> posterior surface of condyle neck

Question 14

lateral ligament OOP functions

Answer 14

prevents excessive rotation in 1st arc of opening

Question 15

lateral ligament IHP attachments

Answer 15

inner horizontal portion

outer surface of zygomatic arch and articular eminence –> lateral surface of disc or lateral pole

Question 16

lateral ligament IHP functions

Answer 16

prevents posterior movement (of condyle into mandibular fossa)
assists/prevents straining of lateral pterygoid m.

Question 17

sphenomandibular ligament attachments

Answer 17

sphenoidal/angular spine (sphenoid) –> lingula

Question 18

sphenomandibular ligament functions

Answer 18

prevents excessive opening (a little)

Question 19

stylomandibular ligament attachments

Answer 19

styloid process (temporal) –> posterior border of mandible

Question 20

stylomandibular ligament functions

Answer 20

oblique orientation: prevents excessive protrusion

Question 21

masseter function

Answer 21

elevate mandible, close teeth together

Question 22

masseter origin

Answer 22

zygomatic arch (inferior and medial)

Question 23

masseter insertion

Answer 23

lateral surface of rami and angle of mandible

Question 24

masseter fibers

Answer 24

deep vertical and superficial oblique

two movements: elevation and protrusion

Question 25

temporalis function

Answer 25

elevate (teeth contact) and retrude mandible

Question 26

temporalis origin

Answer 26

temporal fossa on cranium

Question 27

temporalis insertion

Answer 27

coronoid process, anterior border of ramus, temporal crest

Question 28

temporalis fibers

Answer 28

anterior (vertical) E middle (oblique) E & R posterior (horizontal) R

Question 29

medial pterygoid function

Answer 29

elevate (teeth contact) | medial counterpart to masseter

Question 30

medial pterygoid origin

Answer 30

pterygoid fossa (sphenoid)

Question 31

medial ptergyoid insertion

Answer 31

medial angle of mandible

Question 32

lateral pterygoid function

Answer 32

one: move mandible laterally both: depress, protrude

Question 33

lateral ptergyoid origin

Answer 33

lateral pterygoid plate (sphenoid) and greater wing

Question 34

lateral pterygoid insertion

Answer 34

pterygoid fovea (condylar process) anterior part of articular disc capsular ligament

Question 35

digastric posterior O --> I

Answer 35

mastoid notch --> hyoid

Question 36

digastric anterior O --> I

Answer 36

medial and inferior surface of mandible close to midline --> hyoid

Question 37

suprahyoids

Answer 37

genioyhoids, mylohyoids, digastric

Question 38

suprahyoid functions

Answer 38

depress

Question 39

digastric function

Answer 39

holds mandible in place, hyoid elevates to assist in swallowing

Question 40

infrahyoids

Answer 40

omohyoid, sternohyoid

Question 41

infrahyoid functions

Answer 41

hold hyoid in place

Question 42

all hyoid mm.

Answer 42

open mouth, depress mandible

Question 43

elevation mm (3)

Answer 43

masseter temporalis (ant vert and mid oblique) medial pterygoids

Question 44

depression mm (2)

Answer 44

both lateral pterygoids | supra and infrahyoids together

Question 45

retrusion (2)

Answer 45

temporalis (post horiz) | suprahyoids (w/ help from infras)

Question 46

protrusion (2)

Answer 46

bother lateral pterygoids masster medial ptergyoid

Question 47

lateral excursion

Answer 47

right lateral ptergyoid moves mandible left

Question 48

biomechanics: 3 orthopedic principles

Answer 48

1. Ligaments do not participate actively in function of TMJ. They restrict/permit movements. 2. Ligaments do not stretch, they elongate if traction force is applied, causing normal joint function to be compromised. 3. The articular surfaces of TMJ must maintain contact (achieved by elevator muscles, capsular ligament).