Cervical, Vertebrae and TMJ Flashcards
name the craniovertebral ligaments
- posterior atlanto-occipital membrane
- posterior atlanto-axial membrane
- anterior atlanto-occipital membrane
- anterior atlanto-axial membrane
- tectorial membrane
- ligamentum nuchae
name the spinal ligaments
- ligamentum flavum
- anterior longitudinal ligament
- posterior longitudinal ligament
- supraspinous ligament
describe the structure of the atlanto-occipital articulation
convex occiptial condyles articulate with concave superior facets of the atlas
synovial plane joint
describe the structure of the atlanto-axial articulation
dens and anterior arch of atlas/transverse ligament - synovial pivot joint
inferior facets of the atlas with superior facets of the axis - biconvex with meniscoids
what is the role of the transverse ligament? What motion does it help limit?
prevents anterior displacement of C1 on C2
what is the role of the alar ligament? What motion does it help limit?
it becomes taut in neck flexion and during axial rotation
limits lateral flexion and prevents distraction of C1 on C2
What conditions can compromise the integrity of the transverse ligament? What does that result in? What are some possible dangers?
RA and Down’s syndrome
instability of C1/C2 joint
C1/C2 can slide and compress the spinal cord and even cause paralysis
describe the orientation of lower cervical facet joints
approximately 450 off frontal plane and transverse plane
maximizes motion
what osteokinematic motions occur at the cervical spine?
- Flexion/Extension
- Lateral flexion
- Rotation
- Protraction/Retraction
what produces protraction at the cervical vertebrae
combo of
lower C-spine flexion and upper C-spine extension
what produces retraction at the cervical vertebrae?
combo of
extension in lower C-spine and flexion in upper C-spine
what is the primary osteokinematic motion at the atlanto-occipital joint?
flexion/extension
describe the arthrokinematics at the atlanto-occipital joint?
convex (occipital condyle) on concave (superior facets of atlas)
opposite roll and glide/slide
T/F: movements in the transverse plane are limited at the atlanto-occipital joint?
TRUE
limited by deep joint congruency
Atlanto-occpital flexion = occipital condyle roll ______ and glide ________
Atlanto-occipital extension = occipital condyle roll _____ and glide _______
- anterior; posterior
- posterio; anterior
what is the primary osteokinematic motion that occurs at the atlanto-axial joint?
rotation
describe the arthrokinematics at the atlanto-axial joint
inferior facet of atlas/superior facet of axis
gliding → ipsilateral posterior glide with contralateral anterior glide
what limits rotation at the atlanto-axial joint?
alar ligaments
what limits movement in the sagittal plane at the atlanto-axial joint?
inferior facet of atlas/superior facet of axis → no gliding
limited by transverse ligament
atlanto-axial joint tilt instead
what limits tilting of the axis at the atlanto-axial joint with flexion?
transverse ligament
what coupling motion occur in the lower cervical spine?
lateral flexion with rotation coupled in the same direction
what would occur if either lateral flexion or rotation was done in isolation rather than in a coupling motion?
the facet joints would come into contact with one another blocking the motion
describe the arthrokinematics that occur during flexion/extension of C3-C7
flexion = inferior facet (of superior vertebrae) glides anterior and superior to superior facet (of inferior vertebrae)
extension = inferior facet (of superior vertebrae) slides posterior and inferior to superior facet (of inferior vertebrae)
describe the arthorkinematics that occur during rotation in C3-C7
same side as rotation = inferior facet glides posterior and slightly inferior
opposite side as rotation = inferior facet glides anterior and slightly superior
descibe the arthrokinematics that occur during lateral flexion of C3-C7
same side - inferior facet glides inferior and slightly posterior
opposite side - inferior facet glides superior and slightly anterior
describe the arthrokinematics of R rotation of C4-5
R (ipsilateral) C4 facet glides posterior and slightly inferior on C5 facet
L (contralateral) C4 facet glides anterior and slighly superior on C5 facet
what is the overall function of the cervical spine?
stability and protection
C-spine demonstrates most flexibility
what are concerns with muscular imbalance and poor posture?
prolonged protraction results in forward head posture
lengthening of deep neck flexors and scapular retractors and tightening of the pecs and upper trap/levator scapulae
what is the benefit of lordotic and kyphotic curves? Drawback?
increased ability to resist compressive load
opportunity for shear forces to act, particularly at regions of transition between curves
what is the role of the vertebral body?
weight-bearing structure of spinal column, resist compressive loads
what is the role of the pedicles?
transmit tension and bending forces from posterior elements to vertebral body
what is the role of the laminae?
transmit force from articular, transverse and spinous processes to the pedicles
what is the pars articularis?
portion of the laminae between the superior and inferior articular processes
subject to bending forces
what is the role of the articular facet processes?
form facet joints and contribute to the articular pillar
what is the role of the spinous process?
serve as a muscle attachment and provide mechanical lever
may also serve as boney block to motion
what is the role of the transverse processes?
serve as muscular attachment and provide mechanical lever
what are some concerns you may have if someone has a bilaterally pars interarticularis fracture?
spondylolisthesis (forward slipping of the vertebrae)
can lead to compression of the spinal cord leading to neurological deficits
most commonly occurs at L5/S1 secondary to angulation of this segment
what is the purpose of the intervertebral discs?
- increase available motion
- transmit load
- stabilization of spine
- provide space betwen vertebrae and exiting spinal nerves
What are the components of the intervertebral disc?
- nucleus pulposus
- annulus fibrosus
- vertebral end plate
what is the annulus fibrosus?
fibrous outer ring of the intervertebral disc
60-70% water
collagen and elastin arranged in 15-25 concentric layers
fibers oriented 650 from vertical
what is the role of the annulus fibrosus?
helps keep the nucleus pulposus inbetween the vertebrae
capable of resisting distraction, sheer and torsion forces
what is the vertebral end plate?
cartilaginous layer covering the S/I surfaces fo the disc
0.6-1 mm of cartilage in adults
strongly attached to annulus fibrosis but not the vertebral body
what can occur with an end plate fracture?
nuclues pulposus starts to herniate
T/F: 80% of force is transmitted through the intervertebral disc
TRUE
what position increase the pressure on the disc the most?
Most = forward bending w/load in front of body
slouching > sitting erect
What motions are available at an interveterbral joint?
- gliding
- AP, ML and torsional
- distraction and compression
- rotation (also called tilt)
- AP, lateral direction
T/F: zygapophyseal (facet) joints do not contain any fibromeniscoids?
FALSE
they do have them
define coupling
consistent association of one motion about an axis with another motion around a different axis
lateral flexion with rotation is an example
what influences spinal coupling patterns?
- spinal posture
- spinal curvature
- orientation of articulating facets
- fluidity/elasticity/thickness of the disc
- extensibility of the muscles, ligaments and joint capsules
describe the kinematic role that intervertebral joints have
- determine magnitude of movement
- distribute load
- create space for movement and passage of the spinal nerve roots
describe the kinematic role of facet joints
determine the direction of the movement
“train tracks”
Spinal osteokinematics decribe the movement based on the direction of what?
superior segment’s anterior portion
(front of inferior facet of the superior vertebrae)
what are the arthokinematic motions that occur at the intervertebral joints with each osteokinematic motion?
- approximation/distraction and gliding
- tipping
what are the arthokinematic motions that occur at each facet joint with each osteokinematic movement?
approximation/gapping and gliding
what is the overall function of the spinal musculature?
- control posture
- stabilize axial skeleton
- protect spinal cord and internal organs
- generate intra-thoracic and intra-abdominal pressure
- produce torque for movement of the body
- mobility of head and neck for optimal place of eyes, ears, and nose
what bones make up the TMJ?
mandible and temporal bone
what is the purpose of the articular disc at the TMJ?
separate upper and lower articulation
cushions the large repetitive force of mastication
describe the articular surfaces of the TMJ joint
articular eminence and mandibular condyle are both convex resulting in incongruent joint
T/F: the TMJ joint is covered in hyaline cartilage
FALSE
covered with fibrocartilage
if both articular surfaces of the TMJ are convex, how does it move?
articular disc is biconcave to allow both surfaces to remain congruent throughout ROM
result → joint is separated into a S/I joint
describe the articulations of the superior and inferior joint in the TMJ
superior ⇒ articular eminence with superior disc
inferior ⇒ condyle with lower disc
what are the attachments of the articular disc at the TMJ?
- medial and lateral poles of condyle
- joint capsule and lateral pyterygoid anterioly
- bilaminar retrodiscal pad posteriorly
what does the attachment of the articular disc on the medial and lateral poles of condyle allow for?
the condyle to rotate freely on the disc in the AP direction
what does the attachment of the articular disc to the joint capsule and lateral pyerygoid at the TMJ allow for?
it restricts posterior translation of the disc
what does the attachment of the articular disc to the bilaminar retrodiscal pad allow for?
superior lamina - assists the disc with translating anteriorly with mandibular depression
inferior lamina - limits forward translation
what is the makeup of the joint capsule of the TMJ?
capsule in thin and loose AP and relatively firm ML
what is the most common direction of dislocation of the TMJ and why?
anterior, due to lack of strength of anteiror capsule and the incongruence of the articular surfaces
name the ligaments of the TMJ and describe their function
- lateral (TM) ligament
- stabilize lateral portion of capsule, help guide movement of condyle during opening
- Sylomandibular ligament
- weakest of 3 with questionable function
- Sphenomandibular ligament
- swinging hinge that suspends the mandible
what is the normal resting position of the TMJ?
lips closed and teeth several mm apart
maintained by low level activity of the temporalis muscle
what are the osteokinematic motions at the TMJ?
- elevation/depression
- protrusion/retrusion
- L/R lateral excursion
how and at which part of the joint does the first part of the mouth opening occur?
50% of motion occurs as rolling the lower joint
posterior roll (depression)
disc remains stationary, condyle on temporal bone is where movement occurs
how and at which part of the joint does the second part of the mouth opening occur?
50% of motion occurs in the upper joint as gliding
anterior glide in upper portion
disc pulled anteriomedially by lateral pterygoid and then slides along with condyle
how and at which part of the joint does the first part of mouth closing occur?
50% motion occurs in the upper joint as a posterior glide
how and at which part of the joint does the second part of mouth closing occur?
last 50% of motion occurs in the lower joint as an anterior roll
how and at which part of the joint does protraction of the TMJ occur?
anterior and slighlty inferior glide of condyle and disc
how and at which part of the joint does retraction of the TMJ occur?
posterior and slightly superior glide of the condyle and disc
T/F: no rotation (or rolling) occurs with protrusion and retraction of the TMJ?
TRUE
what occurs on the ipsilateral side during TMJ lateral excursion?
primarily side-to-side translation of condyle and disc within the fossa
ipsilateral condyle glides posteriorly (retrusion)
what occurs on the contralateral side during TMJ lateral excursion
primarily side-to-side translation of condyle and disc within fossa
anterior glide on the contralateral condyle
what muscles and forces act on the TMJ during opening?
- primarily gravity
- digastric
- suprahyoids
- inferior lateral pterygoid
what muscles and forces act on the TMJ during closing?
- temporalis
- masseter
- medial pterygoid
- control of disc vis lateral pterygoid (eccentric control)
what muscles and forces act on the TMJ during protrusion?
- bilaterally superior masseters
- bilaterally M/L pterygoids
what muscles and forces act on the TMJ during retrusion?
- bilaterally posterior fibers of temporalis
- bilateral deep fibers of masseter
- bilateral anterior digastric
what muscles and forces act on the TMJ during lateral excursion?
- contralateral M/L pterygoid (pull condyle forward)
- ipsilateral temporalis (pull condyle posterior)
what is the normal ROM for the different motions of the TMJ?
- opening - 35-55 mm
- function = 25-35 (2 knuckles)
- lateral excursion - 10-15 mm
- protrusion - 3-9 mm
- retrusion - about 3 mm
what is TMD?
a broad/vague term used to describe dysfunctions associated with TMJ
what symptoms are associated with TMD?
- pain
- popping
- reduced bite force
- reduced ROM w/mouth opening
- HA
- tinnitus trigger points
what factors are associated with TMD?
- stress/emotional disturbance
- daily oral parafunction habits (teeth grinding)
- asymmetric muscle activity
- sleep bruxism (teeth clenching during sleep)
- chronic forward head posture
- C-spine pathology
- sensitization of the CNS
describe what is occuring during mouth opening/closing when there is disc replacement with reduction
disc sits anterior, not in anatomical position
the disc does not move with the condyle like it normally would, instead it relocates during opening and subluxes during closing
what is a reciprocal click?
an click that occurs during jaw opening as the disc relocates
then when the jaw is closing, there is a click as the disc gets squeezed abnormally and subluxes anteriorly
what is occuring during mouth opening/closing when there is disc displacement without reduction?
there is a partial displacement or dislocation of the disc in resting position
thus the mandiblar condyle is unable to pass over the posterior border of the disc during opening
since the disc doesn’t relocate it blocks translation and limits motion at durng opening/closing
how does posture and the cervical spine impact the TMJ?
head and neck position may affect tension in cervical muscles which can influence the function of the mandible
