TMJ Flashcards
TMJ
Temporomandibular Joint
What kind of joint is the TMJ
Synovial and Ellipsoid
Artificular surfaces are covered by
White Fibrocartilage
What separates the joint into 2 separate cavities?
Articular Disc
TMJ functions like two separate joints:
one above the disc and one below
Which two movements occur
Rotation and Gliding or Translation
Rotation occurs
in the Lower Cavity; from the beginning to midrange of movement
Gliding occurs
in the Upper Cavity; is a sliding movement of the condyle and disc along the slope of the articular eminence. It occurs from midrange to full range of opening
Capsule of TMJ
is thin and loose
Synovial membrane lines the
capsule, above and below the disc, but does not cover the disc
We have _ _ permanent teeth
32
What are the 3 Ligaments of the TMJ TSS
Temporomandibular
Sphenomandibular
Stylomandibular
Muscles of the TMJ are
Temporalis
Masseter
Lateral Pterygoid
Medial Pterygoid
Actions of the TMJ are
Depression (opening)
Elevation (closing)
Protrusion
Retraction
Lateral Deviation of the Mandible
Muscles that help depress the TMJ are
Lateral Pterygoid
Muscles that help elevate the TMJ are
Temporalis, Masseter, Medial Pterygoid
Muscles that help with Protrusion
Lateral and Medial Pterygoid Muscles
Muscles that help with Retraction
Temporalis (posterior fibres)
Muscles that help with Lateral Deviation of the Mandible
Medial and Lateral Pterygoids perform Lateral Deviation to Opposite Side
TMJ is very vascular so avoid using
heat
Lateral Pterygoid work throughout opening and closing. On opening it _____ while on closing it _________
On opening, initially the superior head of the LP is relaxed and the lower heads are contracted. On closing, the opposite occursl
What is attached to the front and the back of the Disc
Front: Superior Head of the LP
Back: Posterior Connective Tissue
Causes of Locking in Opening
Dislocation of TMJ due to hypermobility
Causes of Locking in Closing
Condyle can rotate but cannot glide forward due to:
1. Muscle Spasm of Temporalis and Masseter
2. Disc has slid in front of the condyle and blocks the forward movement
How do you Palpate the Muscles:
Masseter, Temporalis, Condyles of the Mandible, Mastoid Process
How do you check TMJ Mobility
Fingers in Ears and how
Palpate the Condyles and how
What is the normal range of the TMJ depression (opening)
Two Knuckles
Three Fingers
43mmT
TMJ Arthrokinematics
Rest Position
Rotation
Functional Opening
Translation
Closure (half way to close)
In the Rest Position
Joint in loose pack position
Connective Tissue at Rest
Superior and Inferior heads of LP at Rest
During Rotation
Mid Opening
Superior head of LP relaxed
Inferior head of LP contract
During Functional Opening
Superior and inferior heads of LP contract to guide disc and condyle shortly forward
Posterior Connective Tissue in functional tightening
During Translation
Full Opening
Disc and condyle glide anterior and caudal guided by joint surface
Superior and inferior heads of LP contract to guide disc and condyle fully forward
Posterior Connective Tissue Tightens
Closure (half way to close)
Condyle joint surface glides posteriorly
Superior head of LP contract
Inferior head of LP relax
Posterior Connective Tissue returns to functional resting position
