TMJ Flashcards
(84 cards)
How many times is TMJ used daily
1500-2000 times
Who is TMJ 3-5x more prevalent in
Women around reproductive age
What is Occulsion
Functional relationship between maxillary and mandibular teeth
What is Bruxism
Grinding
What is clenching
Overacted masseter and temporalis resulting in increased compressive force between teeth
What is the free way space
Space between occluding surfaces of teeth when the mandible is in resting positions
2-4 mm normla
What is considered an over bite
The mandibular center incisor that is covered by the maxillary center incisor when the mandible is in the maximally occluded position
What is normal range for over bite
1/3 of the mandibular center incisor
What is over jet
Horizontal distance between the maxillary arch and the mandibular arch when the mandible is in its maximally occluded position
What is the normal range for overjet
3-6mm
What is underbite
Mandibular teeth sit further anterior than maximllary teeth
What is cross bite
Occlusal irregularity where the mandibular teeth and maxillary teeth are not in line with the center incisors
What is open bite
Full occlusion , molars are in approximation but front teeth dont touch
What kind of joint is the TMJ
Diarthrodial
- synovial joint with fibrocartilaginous surfaces and articular disc
What is the TMJ disc covered with and how should it move
Fibrocartilage
Bicconcave and should move with the mandibular condyle throughout jaw movement
Where does the disc attach for TMJ anteriorly and posteriorly
Anteriorly to the joint capsule and the superior lateral pterygoid
Posteriorly to the retrodiscal tissue
What are the 3 divisions of teh disc and are they vascular
V 1. Anterior: vascular and neural
2. Intermediate: avascular and aneural
3. Posterior: vascular and neural
What happens at the inferior cavity and superior cavity of the disc for TMJ
The inferior cavity—this is where rotation of the condyle occurs
* The superior cavity—this is where translation of the condyle occurs
Retrodiscal tissue is ____ and ____
vascular and nociceptive
Where is the capsule thicker
Medial and lateral
What TMJ function is lateral pterygoid invovled in
Elevation
Depression
Protrusion
Lateral excursion
EVERYTHING BUT RETRUSION
What mm are invovled in retrusion
Deep fibers of masseter, temporalis,
suprahyoids (digastric)
What mm are invovled in depression
Inferior fibers of lateral pterygoid,
suprahyoids, infrahyoids (indirectly)
What mm are invled in elevation
Masseter, temporalis, medial
pterygoid, superior fibers of lateral
pterygoid (stabilize the disk)
LTMM-like too much mastication