1. No category

TEMPOROMANDIBULAR JOINT
ANATOMY
PATHOPHYSIOLOGY
SURGERY
JOINTS- WHAT ARE THEY?
• Osseous elements which are multiple that are
joined by a variety of structural elements.
• These co-aptations are grouped as arthroses
ARTHROSES
 FORCES
 Tensile,compres
sive,shear and
torsion
 Concerned
with differential growth,
transmission of forces and with
movement
TYPES OF ARTHROSES-2
• 1.SYNARTHROSES: which are solid nonsynovial joints. Can be fibrous or cartilaginous.
• Fibrous denotes intramembranous ossification
• Cartilaginous denotes endochondral
ossification
TYPES OF ARTHROSES-2
• 2. DIARTHROSES: which are cavitated synovial
joints
• Characterized by having articular surfaces
covered by cartilage(hyaline or fibrocartilage)
with its lubricated smooth wear resistant
surface which glides over its fellow with
minimal friction
SYNARTHROSES-TYPES
• Sutures,synostoses
• Gomphoses (peg and socket)
• Synchondroses (manubriosternalis)
DIARTHROSES-TYPES
• Can be simple(one pair of articulating ,
surfaces), compound(more than one pair of
surfaces), or complex(with intracapsular
meniscus or disc)
• Surface shape:plane, spheroid(ball and
socket), ellipsoid, ginglymus,
bicondylar,trochoid(pivot) and sellar(saddleshaped)
THE TMJ
Are the only synovial joints with an
articular disc
TMJ Classification
• Anatomic Classification:
– Diarthrodial – two joints (joint spaces)
• a joint that contains the following characteristics
– a freely movable joint
– bony surfaces are covered with hyaline or fibrocartilage
– lined by a synovial lining and contains synovial fluid
TMJ Classification
• Functional classification:
– Ginglymo - arthroidial
• Ginglymoid: rotation - inferior joint space
• Arthroidial: translation - superior joint space
TMJ Classification
• The mandible functions as a class III lever system
– Load - occlusal surface
– Fulcrum - TMJ
– Force - muscles of mastication
Anatomy Overview
 Temporomandibular joint…
 -the articulation of the mandibular condylar process with the
glenoid fossa/articular eminence aspect of the temporal bone.
Also includes the interposed articular disc and collateral
ligamentous attachments.
 -is an encapsulated, synovial joint.
 -classified as a ginglymo-arthroidal joint due to its ability to
function as a hinge as well as a gliding type of joint.
 -functions as a Class III lever system.
QUESTION: ANATOMY
What are the six (6) components of
the temporomandibular joint
articulation?
•
•
•
•
•
•
Condyles
Articular surface of the temporal bone
Capsule
Articular disc
Ligaments
Lateral pterygoid
Osseous components
TOMOGRAPHC SCAN OF JOINT
Bony components
• Condyle of mandible
• Articular tubercle of temporal bone
• Mandibular fossa (glenoid)of temporal bone
SOFT TISSUE COMPONENTS
•
•
•
•
•
Muscles and ligaments
Disk
Posterior disk attachment
Joint capsule
Synovia
LIGAMENTOUS SUPPORT
• Articular capsule-attached to temporal bone
around the edges of the fossa and the
articular tubercle and to neck of condyle
• Sphenomandibular ligament-medial to the
joint, runs from spine of the sphenoid bone to
the lingula
LIGAMENTOUS SUPPORT CON’T
• Stylomandibular ligament-posterior to the
joint, runs from the tip of the styloid process
to the angle of the mandible
• Temporomandibular ligament-runs from the
lateral zygomatic process, anterior to the
capsule, to the mandibular neck
MUSCLES OF MASTICATION
• Masseter-completely covers the ramus, arises
from zygomatic arch and inserts to lateral
ramus,deep to the external lobe of parotid
gland. It is an elevator of the jaw
• Temporalis-arises from the lateral aspect of
the cranium, passes deep to the zygomatic
arch, and converge onto the coronoid process
MUSCLES CON’T
• Temporalis-anterior and medial fascicles
elevate the jaw;posterior fascicles retract the
jaw
• Lat. Pterygoid-superior head arises from the
infratemporal surface of the sphenoid bone
and inserts into the articular capsule and disc;
the inferior head arises from the lateral pteryg.
pl. and inserts into condylar process
MUSCLES CON’T.
• Action of Lat. Pteryg.-opens the jaw by pulling
the condyle and the articular disc anteriorly.
1)Together, the rt. and lt. lateral pteryg. mm
protrude the jaw. 2)Unilaterally, they swing
the jaw to the opposite side and thus effect
the grinding motion of mastication
MEDIAL PTERYGOID
• Deep part arises from the lateral pterygoid
plate and the pyramidal process of the
palatine bone. The smaller superficial part
arises from the tubercle of the maxillla and
inserts into the periosteum of the angle of the
mandible. Is a strong elevator of the mandible
DISC POSITION
MOVEMENTS
• Elevation/depression occurs in the
inframeniscal compartment as the condyle
rotates on the articular disc
• Protrusion/retraction occurs in the
suprameniscal compartment as the articular
disc glides anteriorly and posteriorly along the
temporal bone between the fossa and the
articluar tubercle
Anatomy Overview
TEMPOROMANDIBULAR DISORDERS
• A collective term used to describe a number
of related conditions that involve the TMJ’s,
masticatory muscles, and associated
structures; these conditions may present with
facial pain, joint noises, limited jaw function,
and other symptoms-ear ache, headache,
tinnitus, neck/shoulder pain
HISTORICAL REVIEW
• Costen syndrome 1934
• Temporomandibular joint pain dysfunction
syndrome 1955
• Myofascial pain and dysfunction 1969
• Facial arthromyalgia 1974
• Temporomandibular disorders 1983
• Craniomandibular disorders 1993
MOST COMMON TMDs
• Myofascial pain and dysfunction
• Internal derangement
• Osteoarthrosis
MYOFASCIAL PAIN AND DYSFUNCTION
• Refers to a group of poorly defined muscle
disorders (eg, fibromyalgia) characterized by
diffuse facial pain and episodic limited jaw
opening
• May result from parafunctional habits and
significant relationship to psychophysiologic
disorders such as stress or depression
INTERNAL DERANGEMENT
• Abnormal relationship of the articular disc to
the mandibular condyle, fossa,and articular
eminence, interfering with the smooth action
of the joint (Dolwick 1983)
• Is a localized mechanical fault within the joint
• Synonymous with disc displacement
WILKES CLASSIFICATION
• STAGE I: TMJ clicking/no pain/no radiographic
DJD
• STAGE II: +Jt sounds/pain with intermittent
locking but no x-ray DJD
• STAGE III: As II, but with x-ray DJD
• STAGE IV:ADD without reduction/DJD
• STAGE V: Disc perf./Advanced DJD
OSTEOARTHROSIS
• Is a nanpainful, localized degenerative joint disease that
mainly affects bone and articular cartilage.
• It is often idiopathic, but predisposing factors such as old
age, repetitive trauma (bruxism), abnormal joint
posturing, or multiple surgical procedures may be
involved. If painful,then referred to as osteoarthritis
DEGENERATIVE CHANGES IN CONDYLE
EPIDEMIOLOGY
• About 60-70% of the population have features
of TMDs
• About 20-30% report symptoms of TMDs
• About 5% of people with TMD symptoms
actually seek treatment
• The female:male ranges from 3:1 to 9:1