TMJ Lecture Flashcards
How much freeway space is normal between your teeth
2-4mm
your teeth should not be touching when resting
Bruxism
Grinding teeth
Occlusion
Functional relationship between maxillary and mandibular teeth
What is the normal amount of overbite
The maxillary teeth should cover approximately 1/3 of the mandibular teeth
what is overjet?
How far infront the maxillary teeth are from the mandibular teeth
What is crossbite?
Mandibular teeth and mandibular teeth are not in line with central incisors
How do you name crossbite, which side?
Judged by the side that the mandible is shifted towards
What movement happens at the inferior cavity of the disc
rotation of the condyle occurs
what movement happens at the superior cavity of the disc
Translation
Which part of the disc is vascular/neural, which is avascular/aneural?
Anterior and posterior are vascular and neural
middle portion is not
Describe the shape of the TMJ disc
biconcave
Which head of the lateral pterygoid attaches to the disc
superior head
what structure is the pain generator in excessive anterior translation
retrodiscal laminae
The superior retrodiscal laminae does what?
the inferior does what?
superior- allows anterior translation
inferior- prevents excessive anterior translation
What muscles do elevation of the TMJ
Masseter
Temporalis
Medial pterygoid
Superior fiber of laterel pterygoid
What muscle helps stabilize the TMJ disc
superior fiber of lateral pterygoid
What muscles help with depression
Inferior lateral ptery
suprahyoids/infrahyoids
What muscles help with protrusion
Superficial masseter
medial pterygoid
lateral pterygoid
What is the only action that the lateral pterygoid does not do
retrusion
what muscles do retrustion
deep fibers of masseter
temporalis
suprahyoids(digastric)
What muscles do lateral excusion
contralateral medial and Lateral pterygoid
ipsilateral temoralis and masseter
What muscles stabilize the hyoid bone
infrahyoids
what muscles are responsible for depression and retrusion of mandibles
suprahyoids
generally muscles that _____ the jaw are tight
muscles that ______ the jaw are weak and inhibited
close
open
What nerve innervates the TMJ area
trigeminal V3
What is the resting position of the disc on the condyle
should sit slightly anterior to the condlye
_______ occurs in the first 20-25mm of motion (early phase)
rotation
first _______ occurs then __________ during TMJ opening
rotation, translation
when the anterior mandible moves posteriorly and inferiorly (your jaw opening), the condyle moves…
anteriorly and inferiorly
when your jaw closes, the anterior mandible moves anteriorly and superiorly
the condyle moves…
posteriorly and superiorly
during lateral deviation, ipsilateral condyle ________
the contralateral condyle ________-
ipsilateral rotates
Contralateral translation
the mandible slides _________ during protrusion and _________ during retrusion
slightly downward
slightly upward
what is normal TMJ opening
what is functional TMJ opening
normal 40-60
functional: 35
causes of tmj dysfunction
grinding/clenching
gum chewing
oral fixation (chewing on things)
excessive yapping
jaw pain is correlated with _____ tone
cervical muscle tone
What happens during Anterior Disc DIsplacement with reduction ADDwR
Condyle jumps over the disc causing a click during opening and closing
disc is too far forward
With ADDwR, the disc can displace anterior again with closing, causing a click, due to ________-
excessive contraction of lateral pterygoid
Subjective: “I used to pop and click”
Reduced ROM
Anterior disc displacement without reduction
ADDwoR
Anterior disc displacement without reduction
ADDwoR
reduced ROM
no popping
disc stays in front of the condyle the whole time
ADDwoR limited opening vs no limitation in opening
Limited opening- disc blocking the condylar head
no limitation: disc is completely displaced anteriorly
Associated conditions with TMJ Dysfunction
Major 2: Headache, neckpain
vertigo, ear issues, neuralgia, chronic pain
motion analysis:
C shape opening deviates to the _________–
side of restriction
motion analysis: : S shape opening
lack of motor control
motion analysis: Deflection w/ opening
anterior disc displacement (typically towards side of displaced disc)
cotton roll test bite object on painful side molars
Pain increased:
Pain decreased:
Pain increased: muscular origin
Pain decreased: joint related- to confirm test on non-painful side, this should result in pain
Centric relation provocation test
Grasp lower mandible w/ index and ring finger externally w/ thumb ontop of the mandibular teeth
keep jaw slightly open and push anterior-superior
(basically just mashing the disc with the mandible)
positive if pain recreated anterior to tragus
indicates disc issue
