552: Exam 2: Tmj Beginning -Muscle

Front 1

what is mastication

Back 1

process of chewing, tearing or grinding food with teeth

Front 2

mastication involves interaction of what 3 components

Back 2

muscles of mastication, teeth, pair of TMJ joints

Front 3

what bones are related to the structure (or function) of the TMJ

Back 3

- mandible
- maxillae
- temporal
- zygomatic
- sphenoid
- hyoid

Front 4

what is the largest facial bone

Back 4

mandible

Front 5

how does the mandible relate to the muscles of mastication

Back 5

all muscles of mastication attach either directly or indirectly to the mandible

Front 6

what forms the "upper jaw"

Back 6

the right and left maxilla fusing together

Front 7

what does the superior extensions of the maxillae form

Back 7

the floor of the nasal cavity and orbit of the eyes

Front 8

what do the lower horizontal portions of the maxialle accept

Back 8

the upper teeth

Front 9

what is the mandibular fossa

Back 9

the boy concavity of the TMJ

Front 10

what forms the anterior mandibular fossa

Back 10

articular emminence

Front 11

the mandibular fossa is found on what bone

Back 11

temporal bone

Front 12

when the mouth is fully opened what happens to the condyles of the mandible

Back 12

the condyles of the mandible slide anterior-inferiorly across the pair of sloped articular eminences

Front 13

the right and left zygomatic bones create what

Back 13

the major part of the cheeks and lateral orbits of the eyes

Front 14

what creates the anterior half of the zygomatic arch

Back 14

the temporal process of the zygomatic bone

Front 15

what creates the postieor half of the zygomatic arch

Back 15

the zygomatic process of the temporal bone

Front 16

how does the sphenoid bone relate to the TMJ

Back 16

bone does not contribute to the structure, but provides proximal attachments for medial and lateral pterygoid muscles

Front 17

when articulated with the cranium where does the sphenoide bone lie

Back 17

transversely across the base of the skull

Front 18

where does the hyoid bone lie

Back 18

U-shaped bone at the base of the throat, just anterior to the body of the 3rd cervical vertebra

Front 19

what is the shape of the body of the hyoid

Back 19

convex ANTERIORLY

Front 20

what form the slightly curved sides of the hyoid

Back 20

the bilateral greater horns

Front 21

many muscles involved in ____, ____, and _____ attach to the hyoid bone

Back 21

movement of the tongue, swallowing, and speaking

Front 22

many muscles involved in ____, ____, and _____ attach to the hyoid bone

Back 22

movement of the tongue, swallowing, and speaking

Front 23

how many teeth do the mandible and maxillae contain

Back 23

each contain 16 permanent teeth (meaning 32 total teeth)

Front 24

what does the structure of teeth signify

Back 24

it reflexts its function in mastication

Front 25

how many teeth do the mandible and maxillae contain

Back 25

each contain 16 permanent teeth (meaning 32 total teeth)

Front 26

what are the basic parts of each tooth

Back 26

two basic parts: crown and root

Front 27

what does the structure of teeth signify

Back 27

it reflexts its function in mastication

Front 28

what is the role of the peridontal ligaments

Back 28

attach the root ot the teeth with their socket

Front 29

what are the basic parts of each tooth

Back 29

two basic parts: crown and root

Front 30

what are cusps

Back 30

conical elevations that arise on the surfaceof a tooth

Front 31

what is the role of the peridontal ligaments

Back 31

attach the root ot the teeth with their socket

Front 32

what does maximal intercuspation describe

Back 32

the position of the mandible when the cusps of the opposing teeth are in maximal contact

Front 33

what are cusps

Back 33

conical elevations that arise on the surfaceof a tooth

Front 34

what is another word for maximal intercuspation

Back 34

centric relation

Front 35

what does maximal intercuspation describe

Back 35

the position of the mandible when the cusps of the opposing teeth are in maximal contact

Front 36

what is the relaxed postural position of the mandible

Back 36

one that allows a slight "freeway space" (interocclusal clearance) between the upper and lower teeth

Front 37

what is another word for maximal intercuspation

Back 37

centric relation

Front 38

many muscles involved in ____, ____, and _____ attach to the hyoid bone

Back 38

movement of the tongue, swallowing, and speaking

Front 39

what forms the TMJ

Back 39

the condyle of the mandible fitting losely within the mandibular fossa of the temporal bone

Front 40

what is the relaxed postural position of the mandible

Back 40

one that allows a slight "freeway space" (interocclusal clearance) between the upper and lower teeth

Front 41

how many teeth do the mandible and maxillae contain

Back 41

each contain 16 permanent teeth (meaning 32 total teeth)

Front 42

what forms the TMJ

Back 42

the condyle of the mandible fitting losely within the mandibular fossa of the temporal bone

Front 43

what does the structure of teeth signify

Back 43

it reflexts its function in mastication

Front 44

what are the basic parts of each tooth

Back 44

two basic parts: crown and root

Front 45

what is the role of the peridontal ligaments

Back 45

attach the root ot the teeth with their socket

Front 46

what are cusps

Back 46

conical elevations that arise on the surfaceof a tooth

Front 47

what does maximal intercuspation describe

Back 47

the position of the mandible when the cusps of the opposing teeth are in maximal contact

Front 48

what is another word for maximal intercuspation

Back 48

centric relation

Front 49

what is the relaxed postural position of the mandible

Back 49

one that allows a slight "freeway space" (interocclusal clearance) between the upper and lower teeth

Front 50

what forms the TMJ

Back 50

the condyle of the mandible fitting losely within the mandibular fossa of the temporal bone

Front 51

what type of joint is the TMJ

Back 51

synocial joint

Front 52

what type of motion does the TMJ permit

Back 52

rotation as well as translation

Front 53

what is the role of the articular disc

Back 53

to cushion the potentially large and repetitive muscle forces inherent with mastication

Front 54

the disc seperates the joint into

Back 54

two synovial joint cavities.... inferior and superior synovial cavities

Front 55

what is the structure of the mandibular condyle

Back 55

flatened from front to back, with medial-lateral length 2x as long as anterior-posterior length

Front 56

what are the medial and lateral poles

Back 56

short projections of the mandibular condyles

Front 57

what is the general shape of the mandibular condyle

Back 57

convex

Front 58

what lines the articular surface of the mandibular condyle

Back 58

thin/dense layer of fibrous connective tissue

Front 59

what is the mandibular fossa divided into

Back 59

two surfaces: articular and non-articular

Front 60

what forms the articular surface of the mandibular fossa

Back 60

articular eminence, occupying the sloped anterior wall of the fossa

Front 61

full opening of th emotuh requires that each condyle move in what direction

Back 61

forward across the slope of the articular eminence

Front 62

the non-articularsurface of the mandibular fossa consists of

Back 62

ver thin layer of bone and fibrocartilage that occupies much of the superior dome and psterior walls of the fossa

Front 63

which of the two surfaces in the mandibular fossa is not an adequate load-bearing surface

Back 63

the non-articular surface

Front 64

the articular disc consists primarily of what tissues

Back 64

dense fibrous connective tissue

Front 65

what is the blood supply to the disc

Back 65

lacks blood supply except for the periphery

Front 66

what are the regions of the disc

Back 66

posterior, intermediate, and anterior

Front 67

what is the shape of the posterior region of the disc

Back 67

convex superiorly and concave inferiorly

Front 68

where is most of the condyle accepted in the posterior region of the disc

Back 68

inferiorly in its concave portion

Front 69

what does the extreme postioer region of the disc attach to

Back 69

the retrodiscal laminae

Front 70

what does the retrodiscal laminae contain

Back 70

collagen and elastin fibers

Front 71

what anchors the disc posteriorly to the bone

Back 71

connections made by the retrodiscal laminae

Front 72

the inferior retrodiscal laminae is ____-rich while the superior retrodiscal laminae is _____-rich

Back 72

inferior retrodiscal laminae is collagen-rich

superior retridoscal laminae is elastin- rich

Front 73

where does the inferior retrodiscal laminae attach

Back 73

to the periphery of the superior neck of the mandible along with the capsule of the TMJ

Front 74

where does the superior retrodiscal laminae attach

Back 74

to the tympanic plate of the temporal bone, just posterior to the fossa

Front 75

what is the shape of the intermiediate region of the disc

Back 75

concave inferiorly and generally flat superiorly

Front 76

where is the thinnes region of the disc

Back 76

the intermediate region

Front 77

what is the shape of the anterior region of the disc (and why?)

Back 77

nearly flat interiorly, and slightly concave superiorly to accomodate to the maximal convexity of the articular eminence

Front 78

the anterior region of the articular disc attaches to (3)

Back 78

1) periphery of the superior neck of the mandible along with the anterior capsule of the TMJ
2) tendon of the superior head of the lateral pterygoid muscle
3) temporal bone just anterior to the articular eminence

Front 79

what causes the dimple on the disc's inferior surface

Back 79

the thin intermediate region

Front 80

what happens to the dimpled intermediate region in maximal intercuspation

Back 80

it fits between the anterior-superior edge of the condyle and the articular eminence of the fossa

Front 81

what is the significance of the position of the disc during maximal intercuspation

Back 81

it protects the condyle as it slides forward across the articular eminence during opening of the mouth

Front 82

the TMJ and disc are surrounded by....

Back 82

loose fibrous capsule

Front 83

anteriorly the capsule, and part of the anterior edge of the disc attach to

Back 83

the tendon of the superior head of the lateral pterygoid muscle

Front 84

anteriorly and posteriorly the capsule is _____ for what purpose

Back 84

capsule lax to allow the condyle and disc to translate forward while one opens the mouth

Front 85

what are the supporting conective tissues within the TMJ (6)

Back 85

1) articular disc
2) fibrous capsule
3) collateral ligaments
4) lateral ligament
5) spenomandibular ligament
6) stylomandibular ligament`

Front 86

what is the primary ligament reinforcing the TMJ

Back 86

the lateral (temporomandibular) ligament

Front 87

what is the fiber direction of the lateral ligament

Back 87

combination of horizontal and oblique fibers

Front 88

what is the special function of the superficial oblique fibers of the lateral ligament

Back 88

guiding the movement of the condyle during opening of the mouth

Front 89

what are the accessory ligaments of the TMJ

Back 89

stylomandibular and sphenomandibular ligaments

Front 90

where are the accessory ligaments located

Back 90

medial to the joint capsule

Front 91

what is the role of the accessory ligaments

Back 91

suspend the mandible from the cranium (very limited role in TMJ function)

Front 92

what are the motions at the mandible

Back 92

protrusion, retrucion, lateral excursion, depression, elevation

Front 93

what is protrusion

Back 93

component of opening the mouth maximally

Front 94

what is retrusion

Back 94

component of closing the widely opened and protruded mouth

Front 95

what is lateral excursion

Back 95

side-to-side translation

Front 96

what is depression

Back 96

opening of th emough

Front 97

what is the average that an adult mouth can open .... and what are the points we measure this from

Back 97

50 mm.... from the incisal edges of the upper and lower front teeth

Front 98

what amount of depression is necessary for mastication (and what percent of maximum)

Back 98

18 mm.... about 36% of max

Front 99

what is elevation

Back 99

closing the mouth (used for grinding food during mastication)

Front 100

what are the arthrokinematics during rotational movement

Back 100

mandibular condyle rolls relative to the inferior surface of the disc

Front 101

what are the arthrokinematics during translation

Back 101

mandibular condyle and disc slide essentially together

Front 102

what is condyle-disc complex

Back 102

during translational movement the mandibular condyle and disc slide together

Front 103

since the disc is attached to both the condyle and the temporal bone, what happens to it during extension

Back 103

it is stretched in the direction of the translating condyl

Front 104

what are the arthrokinematics during protrusion and retrusion

Back 104

mandibular condyle-and-disc translates anterior and posteior relative to the fossa

Front 105

what do the condyle and disc follow with protrusion and retrusion

Back 105

the downward slope of the articular eminence

Front 106

what direction does the mandible slide with protrusion and retrusion

Back 106

slightly downward in protrusion and slightly upward during retrusion

Front 107

lateral excursion involves primarily what motion

Back 107

side-to-side translation of the condyle and disc within the fossa excursion

Front 108

what are typically combined with lateral excursion

Back 108

slighty multiplanar rotations

Front 109

early phase of opening the motu involves primarily

Back 109

rotation of the mandible relative to the cranium

Front 110

what do the condyles do in the early phase of opening the mouth

Back 110

rolls posterior within the concave inferior surface of the disc

Front 111

what is the axis of rotation during the early phase of opening the mouth

Back 111

not fixed, it migrates within the vicinity of the condyles

Front 112

what helps initiate the late phase of opening the mouth

Back 112

the rolling motion of the condyle stretches the oblique portion of the lateral ligament

Front 113

what marks the late phase of opening the mouth

Back 113

gradual transition from primary rotation to primary translation

Front 114

what occurs during the late phase translation to the disc and condyle

Back 114

they slide together in a forward and inferior direction against the slope of the articular eminence

Front 115

what is the axis of rotation during the late phase of opening the mouth

Back 115

at the end it shifts inferiorly usually below the neck of the mandible

Front 116

what happens to the disc with full opening of the motuh

Back 116

disc is maximally stretched and pulled anteriorly increasing tension in the stretced, elastic superior retrodiscal lamina

Front 117

the intermediate region of the disc translates forward during the late phase, while remaining between

Back 117

the superior aspect of the condyle and the articular eminence

Front 118

what is the significance of the position of the disc during the late phase

Back 118

it maximizes joint congruency and reduces large variation in intra-articular sterss