Cervical Spine and TMJ Flashcards
Cervical Spine Levels
C1-C7
CS Junctions
Upper Cervical (Craniovertebral): Occiput, atlas, axis | Atypical
-Atlanto-Occipital Articulation - C0-C1
-Atlanto-Axial Articulation - C1-C2
Lower Cervical: C3-C7 | Typical
CS Osteokinematic Motions
Flexion/Extension
Lateral flexion (Sidebending)
Rotation
Atlanto-Occipital Articulation (AO) - C0-C1
Between the head and the neck
Occipital condyles (concave) -> superior articular fossa of Atlas (convex)
AO Arthrokinematics
Boney structure supports:
Sagittal plane movement - majority
Frontal plane movement - minor
Transverse - negligible
Atlanto-Axial Articulation (AA) - C1-C2
Between C1 (atlas) and C2 (axis)
Considered a pivot joint
Ondontoid process (dens) from C2 articulates with anterior arch of atlas and transverse ligament
Supports rotation movement the most
Lower cervical Arthrokinematics
Flex/Ext
Facet Joint
Up and forward = up slide [Flexion]
Down and back = downslide [Extension]
Interbody Joint
Anterior tilt and slide [Flexion]
Posterior tilt and slide [Extension]
Lower cervical Arthrokinematics
Lateral Flexion/Sidebending
Facet Joint
Right bend: Left bend:
Ipsilateral: downslide R downslide L
Contralateral: upslide L upslide R
Interbody Joint
Right bend: Left bend:
Right lateral tilt and slide Left lateral tilt and slide
Lower cervical Arthrokinematics
Rotation
Just Facet Joint
Right: Left:
IpL-downslide R downslide L
CL-upslide L upslide R
Temporomandibular (TM) joint
Articulation
Articular eminence Temporal Bone
Mandibular condyles
Bones that merge to form the structure and contribute to the function of the TMJ
Mandible
Maxilla
Temporal
Zygomatic
Sphenoid
Hyoid
TMJ Classification
Synovial
3 DOF
Shape: Both Convex = incongruent joint
TMJ Osteokinematics
Elevation/Depression
Protrusion/Retrusion
Left & Right lateral excursion (deviation)
TMJ Open-Packed position
Jaw slightly open
TMJ Closed-Packed position
Teeth clenched OR mouth maximally opened
TMJ Articular Disc
Biconcave - Allows the convex surfaces to remain congruent
Separates each TMJ into:
-Superior and Inferior Joint
Superior Joint
Plane joint
Articular eminence temporal bone
superior surface of disc
Inferior Joint
Hinge joint
Mandibular condyle
Inferior surface of disc
TMJ Disc Function
Increase stability
Minimizes loss of mobility
Decrease friction
Decrease biomechanical stress
TMJ Disc Attachments
Medial/lateral poles mandibular condyle
Joint capsule->Anteriorly
Tendon of lateral pterygoid
Bilaminar retrodiscal pad: superior/inferior lamina
Vascularized & Innervated anteriorly/posteriorly
-Avascular & aneural centrally
Superior lamina
Consists of elastic fibers that allow the superior band to stretch
Allows the disc to translate anteriorly along the articular eminence during mandibular depression
Assist in repositioning the disc posteriorly during mandibular closing
Inferior lamina
Tether on the disc, limiting forward translation but does not assist with repositioning the disc during mandibular closing
TMJ Capsule
Lax superiorly, taut inferiorly
Stronger laterally
Highly vascularized and innervated
TMJ Ligaments
TM ligament
Stylomandibular
Sphenomandibular
TM ligament
Strong
Oblique fibers-suspensory ligament, limits downward and posterior motion of the mandible, and rotation of the condyle during mandibular depression
Horizontal fiber-resist posterior motion of the condyle, limits the posterior translation of the condyle protects the retrodiscal pad
Stylomandibular ligament
Weakest
May limit protrusion
Sphenomandibular ligament
Strong
Swinging hinge
May protect from excessive anterior translation
