TMJ Eval & Treat Flashcards
Components of TMJ
-mandibular condyle
– Articular eminence of temporal bone (mandibular fossa)
– fibrocartilage disc
TMJ Disc
-attaches to medial and lateral poles of the condyle
-Attached anteriorly to lateral prerygoid
Anterior band: middle thickness, atnterior to condyle, no vascular supply
Intermediate band: smallest thickness, on top of condyle
Posterior band: thickest, on top of condyle with full mouth closure, attaches to retrodiscal tissue
Inferior Joint
Functions as a hinge joint
-Rolls posterior during opening
Superior Joint
Functions as a plain joint
-Slides anterior during opening
Temporalmandibular ligament
Oblique: limits downward, and posterior motion
Horizontal: resist posterior motion
Both resist lateral displacement
Stylomandibular ligament
Weakest, may limit protrusion
Sphenomandibular ligament
May prevent forward translation
Normal depression
– 40-50 mm
-Two fingers are functional, three fingers are normal
Normal translation and rotation
First rotation: 11 to 25 mm of anterior rotation with a posteriorr roll
Translation: both condyle and disc have anterior slide
Normal protrusion
6-9 mm
Normal retrusion
3 mm
Passive Disc Control
-retrodisc laminate applies traction posterior
-sphenomandibular lig
Active Control of Disc
-superior lat pterygoid eccentrically contracts to control posterly
-Masseter attaches to anterolateral portion of disc to counteract lat pterygoid
-temporalis, med pterygoid, and masseter provide constant pressure on disc
Normal Lateral Excursion
-8-11mm
-Ipsilateral condyle spins
-Contralateral condyle translates anteriorly
Mandibular deviation
Mandible moves away from midline during depression, and stays there
Mandibular deflection
Mandible moves away from midline during depression, but returns
Muscles involved with depression
Digastric, suprahyoids, lower lateral pterygoid
Muscles involved with elevation
Temporalis, masseter, medial pterygoid, superior lateral pterygoid
Muscles of protrusion
Masseter, med and lat pterygoids
Muscles of retrusion
Temporalis, with anterior digastric
Muscles of lateral deviation
Contralateral Pterygoids, ipsilateral temporalis
Longus Colli
-flexion and side bending with contra rot
Longus Capitus
-flexion and side bending with ipsi rot
Dentition
-contact of upper and lower teeth
-normal rest position with 1.5-5mm of space
Anterior Disc Displacement: With reduction
-click during anterior translation with condyle stuck under disc
-2nd click when condyle slips from under disc when translating posteriorly
Anterior Disc Displacement: Without reduction
-no clicks
-ligaments stretches and prevent relocation
-pain with movement
TMJ Disc
-increases congruency, increases mobility, reduces friction, decreases stress
-Lower Part: allows depression and elevation
-Upper Part: Allows protrusion and retraction
Anterior Attachment: joint capsule and Superior lateral pterygoid
Posterior Attachment: Superior and inferior laminae
Medial and Lateral: ligamentous capsule complex