TMJ Flashcards
Joint type
true synovial
gliding, hinging, slight rotation, sliding motion
Articular surfaces are
fibrocartilage
well vascularized and innervated so can regenerate when injured
Upper joint space is what
temporal bone to disc
glides forward and backward
Lower joint space is what
disc to condyle of the mandible
angular joint surface motion
Articular disc
biconcave
well vascularized and innervated except for the middle part! that is where it gets deformed
Resting position of TMJ
jaw closed with 2-5mm between the teeth
DOF
3
Dep/Elevation
Protrusion/Retrusion
Lateral deviation
Depression involves what
anterior translation and glide
Elevation involves what
Posterior and superior glide
Protrusion and retrusion include what
condyle and disc translate together ant/post
Lateral deviation includes what
axial rotation on the ipsilateral side
ant translation on contralateral side
Chewing stroke
depression
lateral deviation (toward working side)
elevation
shear action = compress and shift food up and medial
Temporomandibular ligament
two parts - oblique and horizontal
oblique - neck of condyle to articular condyle - resists downward/post motion
horizontal - lat condyle to post disc - resists post motion of condyle
Stylomandibular ligament
styloid process to post ramus of mandible
limits protrusion
Sphenomandibular ligament
spine of sphenoid to middle surface of ramus
resists excessive forward translation
Mouth opening - early and late phases
early - spin at lower joint space
late - glide at upper joint space
MM that do elevation
massater
temporalis
medial pterygoid
MM that do protrusion
lat pterygoid
masseter
med pterygoid
MM that do lateral deviation
ipsilateral temporalis
ipsilateral masseter
contralateral med/lat pterygoids
MM that do retrusion
post temporalis
digastrics
stylohyoid
sphenomandibular ligament
Buccal
surface next to cheek
Lingual
next to tongue
Labial
next to lips
Mesial
front (center)
Maximal intercuspation
ligual cusps of maxillary premolars and molars rest in deepest parts of occlusal sulci of mandibular premolars and molars
Central occlusion
point of initial teeth contact on closing
ideally is maximal intercuspation
Angles classes of occlusion - class 1
straight profile
Angles classes of occlusion - class II
convex profile
protracted maxilla or retracted mandible
Angles classes of occlusion - class III
concave profile
retracted maxilla
Numbering system - permanent
L to R: 16 to 1 (top)
L to R: 17 to 32 (bottom)
Numbering system - deciduous teeth
L to R: J - A (top)
L to R: K - T (bottom)
Close packed
ant - max opening
post - max retrusion
