temporomandibular joint

TMJ

-____ joint

-articulation between ____ and ____

synovial, mandible, cranium

functional activities of TMJ (4)

mastication, communication, yawning, laughing

parafunctional activities of TMJ (4)

bruxism, chewing pencils, biting nails, resting chin

which type of activity is easily modifiable when it comes to TMJ activities bc they are not essential

parafunctional

mandibular condyle

-____ bony partner of TMJ

-____ on articular surface

convex, fibrocartilage

mandibular fossa

-part of ____ bone

-____ bony partner of TMJ

-two parts

• ____=thin and menbranous

• ____=covered with fibrocartilage

temporal, concave, dome, articular eminence

4 parts of TMJ

mandibular condyle, mandibular fossa, articular eminence, disc

articular disc

-dense ____

-3 regions: ____, ____. and ____ making it ___

-improves ____

fibrocartilage, posterior, middle, anterior, biconcave, joint congruity

posterior region of articular disc

-____

-____

-attaches to ____

• superior part contains ___, helps with ____

• inferior part contains ____, preventing ___ movement

• pad between contains fat, ___, and ____

thick, innervation, retrodiscal laminae, elastin, repositioning, collage, excessive, blood vessels, sensory nerves

intermediate region of articular disc

-____

-____

-____ bearing

-compressed between ____ and ____

thin, aneural and avascular, load, articular eminence and mandibular condyle

anterior region of articular disc

-____

-____

-attachments to ____, ____ joint capsule, tendon of ____

thick, innervated, bone, anterior, lateral pterygoid

functions of articular disc

-reduce ____

-____ joint

-guides ____

contact pressures, stabilizes, arthrokinematics

forces on the articular disc in TMJ

-____ of condyle

-____ pressure

-____ contraction

-____

-elastic recoil of superior ____

translation, intra-articular, muscular, ligaments, retrodiscal laminae

joint capsule of TMJ

-provides ____ and ____ support chewing motions

-more lax ____ and ____ to allow mouth to open

-limit ____ of the disc and condyle

medial, lateral, anterior, posterior, anterior translations

strongest ligament supporting the TMJ

lateral temporomandibular ligament

lateral temporomandibular ligament

-primary reinforcement of TMJ

-____ and ____ fibers

-reinforce ____ capsule

-guides ____ during mouth opening

horizontal, oblique, lateral, condyle

accessory ligaments to TMJ ____ and ____

-____ to joint capsule

-help suspend ____ from skull

stylomandibular, sphenomandibular, medial, mandible

open packed TMJ position:

-space between ___ and ___

lip together, teeth apart, tongue on hard palate, upper and lower teeth

close packed TMJ position

jaw clenched

functional opening of TMJ

18-20mm

opening mouth =

depression

closing mouth =

elevation

anterior translation of mandible without rotation

protrusion

posterior translation of mandible without rotation

retrusion

side to side translatoin

lateral excursion

arthrokinematics of TMJ: early phase ____

-first ___-____ mm of opening

-____ roll of condyle on concave disc (named relative to the rotation of the ___)

-body of mandible moves ____ and ____

depression, 10, 25, posterior, ramus, inferior, posterior

mouth depression TMJ arthorkinematics

1st half = ___

2nd half = ___

posterior roll, anterior slide

arthrokinematics of TMJ: late phase ____

-____ and ____ translation of disc and condyle

-____ pulled taught

depression, anterior, inferior, retrodiscal laminae

arthrokinematics of TMJ: elevation

1st part=

2nd part=

-tension in ___ helps retract disc

-resisted by eccentric contraction of ___

posterior and superior translation, anterior roll, superior retrodiscal lamina, lateral pterygoid

arthrokinematics of TMJ: protrution

mandibular condyle and disc ___

translate anterior and inferior

arthrokinematics of TMJ: retrusion

mandibular condyle and disc ___

translate posterior and superior

arthrokinematics of TMJ: lateral excursion

ipislateral side: ___

contralateral side: ___

condyle spins, condyle and disc translate anteriorly

primary muscles of TMJ

masseter, temporalis, medial pterygoid, lateral pterygoid

secondary muscles of TMJ

suprahyoid and infrahyoid muscles

masseter

bilateral: ___, slight ___

unilateral: slight ___ (bring back to ___)

elevated mandible, protrusion, ipsilateral excursion, neutral

temporalis

bilateral:

unilateral:

elevate mandible, retrusion, ispilateral excursion

medial pterygoid

-____ and ____ heads

-parallels ___ but on internal surface

-bilateral:

-unilateral:

deep, superficial, masseter, elevate mandible, protrude mandible, contralateral excursion

lateral pterygoid

-____ and ____ heads

-bilateral:

unilateral: ___ excursion, ____ condylar rotation

superior, inferior, protrusion, ipsilateral anteriomedial

inferior head of lateral pterygoid ___

depresses mandible

superior head of lateral pterygoid

-resist ___ forces

-dysfunction may contribute to internal ____ to discs

posterior, derangement

infyahyoid muscles ___ hyoid bone

stabilize

suprahyoid muscles assist with ___

mandibular depression

mouth opening

-____ and ____ slide forward during late phase opening

• inferior head of ____ and ____ muscles

-____ check excessive anterior translation of the disc

disc, condyle, lateral oterygoid, suprahyoid, retrodiscal laminae

mouth closing

-concentric contraction of ____, ____, and ____

• ____ and ____ mandible

-eccentric contraction of superior head of ____

• forward tension on ____ and ____

• opposes strong ____ forces from posterior fibers of temporalis

masseter, medial pterygoid, temporalis, elevate, retrude, lateral pterygoid, disc, mandible, retrusion