Intro & Anatomy Flashcards
is a ginglymoarthrodial joint
with hinging or rotation movements in one plane
(ginglymoid joint) & gliding or translation movements
in another plane (arthrodial joint)
The TMJ
_____ contains
the synovial f luid, limits its
motion and maintains the
relationship between the joint
components.
A fibrous capsule
transports nutrients to & waste
products from the articular surfaces & lubricates joint
Synovial f luid(synovia)
What are the 3 Functions of Disc?
- Distributes loading forces
- Decreases wear
- Stabilizes condylar movement
- Articular portion is composed of dense fibrous
connective tissue NOT cartilage - Has some ability to repair itself
- Is devoid of nerves or blood vessels in the
intermediate zone which articulates with the
superior aspect of the condyle - The posterior attachment of the disc is highly
vascularized and innervated
Disc
What is the most innervated and vascular portion of the articular disc?
Posterior/ retrodiscal tissue
The articulating surfaces are lined with dense
______ which
allows for a greater ability to heal
fibrocartilage
A thin layer of cartilage covers the articulating surface
of the bones.
Plays an important role as a stress absorber during
function.
Research suggests that compressive loading is highest
in the anteromedial region of the condyle (1).
Composed of cells and extracellular matrix (i.e.
collagens & proteoglycans).
Articular Cartilage
____ ligaments
Allow the disc to move in anterior-posterior direction
during condylar translation.
Discal ligaments may become inf lamed & painful
because they are vascularized and innervated.
Discal ligaments
_____ ligaments
Attach the disc to the condyle on the medial & lateral
surfaces
Allow the disc to rotate on the condyle during condylar
translation.
Caspular ligaments
____ ligaments (2)
Limits inferior movement
of mandible
Sphenomandibular and Sytlomandibular ligaments
What are the 2 arteries that supply TMJ?
Superficial temporal and maxillary arteries
What 2 nerves innervate the TMJ?
Auriculotemporal V3 and Masseteric nerves
_____ occurs
between inferior
disc surface and
condyle
Rotation
_____ occurs
between the superior
disc surface and fossa
Translation
what 3 muscles elevate or close the mandible?
- Masseter
- Medial pterygoid
- Temporalis
______ muscle: –assists in protrusion & lateral movements
(inferior head) & stabilizes the disc/condyle complex (superior head)
Lateral pterygoid
_______ muscle–assists in depression (mouth opening) &
retrusion
Digastric muscle
What nerve innervates masticatory muscles?
Mand nerve V3
_____ MASSETER:
Elevates the mandible (closes
the jaw)
SUPERFICIAL masseter
_____ MASSETER:
Retrudes the mandible
DEEP masseter
ACTIONS:
*Closes the jaw
*Retrudes the jaw
(with posterior and
middle fibers)
*Deviates the jaw
to the same side
(if unilaterally
contracting)
Temporalis
*Deviates jaw to opposite side
(if contracting unilaterally)
*Helps to elevate the mandible
(closes jaw) in concert with
masseter & temporalis muscles
(if contracting bilaterally)
*Assists the lateral pterygoid in
protrusion
Medial pterygoid
Superior division:
*Pulls disc forward and
check-reins its backward
movement & assists in
closing jaw
Inferior division:
*Protrudes and depresses
the mandible (opens jaw)
*Deviates jaw to opposite
side
Lateral pterygoid
Depresses (opens) &
Retrudes the mandible.
Digastric muscle
A collective term that includes a number of clinical
problems involving the masticatory muscles, TMJ &
associated structures which are identified as the major
cause of non-dental pain in the orofacial region:
1. Musculoskeletal Disorders
2. Articular Disc Disorders
3. Inf lammatory & non-inf lammatory Disorders
TMD
