What does TMJ stand for?
What is the TMJ?
the Articulation between the Condyle of the Mandible Bone
Glenoid (Mandibular) fossa of the Temporal Bone
Where does the Mandibular condyles actually articulate with, which is found anterior to the glendoid fossa?
Each condyle of the Mandible has two parts what are they and waht's it designed for?
1- medial pole
2- lateral pole
for muscular attachment
The TMJ is designated as a ___________, bi-__________ joint
What sort of fine motor is TMJ involved in?
Name the two accessory TMJ strucutres.
1- Fibrocartilagenous disc
2- Bilaminar Retrodiscal Pad
What does the Fibrocartilagenous disc separate the joint into (2)?
1- superior cavity
2- inferior cavity
Where is the Inferior cavity related inferior joint formed?
Inferior Joint is formed:
between Condyle of Mandible
Inferior aspect of the Fibrocartilagenous Disc
Where is the superior cavity related Superior Joint located?
Superior Joint is formed:
between Temporal Articular Eminence
Superior Aspect of the Fibrocartilagenous Disc
What is the Bilaminar Retrodiscal Pad?
Fat pad that attaches to the posterior aspect of the TM disc
What is the Bilaminar Retrodiscal Pad made of(2)?
2- inferior lamina
What does the Superior Lamina contain a large quantity of and what is the function of that substance?
Allows deformation and recoil
What happens when there's an issue with the superior lamina?
Results in an anterior translation of the TM disc
What is a physical propery of the Inferior Lamina and what is the function realted to its physical property?
Inferior lamina is stiff
It is stiff to resist excessive Anterior translation of TM disc
In the Upper TMJ the ______ __________ is lax allowing for more mobility.
The _________ __________ is tight which keeps the disc firmly attached to the Mandibular Condyles
Name the three ligaments related to TMJ.
What is the TM ligament?
a Ligament that attaches from the
Inferior portion of the Condyle of the Mandible
What is the function of the TM ligament?
limiting of the downward, posterior, and rotary movement of the Mandibular condyle
What is unique about the Stylomandibular LIgament out of all three TMJ related ligaments?
Sylomandibular ligament is the weakest
What is the function of Sphenomandibular Ligament?
Sphenomandibular LIgament serves to limit Anterior translation of Mandibular condyle
What are the 5 TMJ movements?
5- Lateral excursion aka deviation
Functionally, Mastication requires how many 'mm's of ROM?
Describe briefly what happens during Depression?
Lateral Pterygoid aka Superior Head applies anterior force to the disc
this is to ensure adequate Anterior translation of Condyle/Disc occurs
Describe briefly what occurs during Elevation.
Lateral Pterygoid aka Superior Head controls Posterior translation of the disc until the condyle has reached its max Posterior rotation
Where does Protusion and Retrusion motion occur?
What action causes Anterior and Inferior slide of the condyle and disc along the 'sloping articular eminence'?
What action involves Posterior and Superior slide?
What allows for the anterior translation of the disc needed for full Protrusion ROM?
compliance of the Bilaminar Retrodiscal Pad
What is the Normal ROM of Lateral Excursion?
During Lateral Excursion the Ipsilateral condyle spins around what axis?
During Lateral Excursion the Contralateral condyle slides anteriorly along what?
along the articular eminence
a small degree of ____ and _____ _______ ______ are required on the contralateral side to obtain full ROM of Lateral Excursion
ipsilateral lateral glide
What are the primary Muscles of Mastication?
What is the function of Temporalis?
Elevation and Retrusion
What are the two attachment site for Temporalis?
Attaches to temporal fossa and coronoid process
What innervates the Temporalis?
Mandibular branch of Trigeminal nerve
Which muscle involved in Mastication causes elevation and protrusion?
what is the attachment site of Masseter?
Zygomatic arch angle of Mandible
What innervates the Masseter muscle in Mastication?
Innervated by Mandibular branch of Trigeminal nerve
The inferior head involved in Mastication is aka Lateral Pterygoid. What is it's function?
Depression and Protrusion
What are the attachment sites for Lateral Pterygoid aka inferior head?
pteragoid plate to Neck of mandible
What innervates the inferior head aka Lateral Pterygoid?
innervated by mandibular branch of Trigeminal nerve
What is the function of the Medial Pterygoid?
Elevation and Protrusion
What are all the attachment sites of Medial Pterygoid
Lateral pteragoid plate
What is Medial Pterygoid innervated by?
Mandibular branch of Trigeminal nerve
What are the two secondary muscles of Mastication?
What is the function of Suprahyoids and name all four of them
What is the function of Infrahyoid and name all four muscles.
Stablizes the Hyoid
Between the Condyles of the mandible and glenoid (Mandibular) fossa of the temporal bone, does it or does it not move in the fossa?
It doesn't move in the fossa
How many degrees of freedom does the TMJ offer?
What does phonation and deglutinition mean?
All human movement is rotary movements on an axil but one where is it and what sort of motion it it?
TMJ some lateral sliding movement
Where is the location where the mandible moves?
anteriorly on the articular eminence
What sort of structure is the BIlaminar retrodiscal pad?
they are laminar which means layered and it has two layers therefore bilaminar in name. One is superior and the other is inferior
What does the elastin fibers in the Bilaminar Retrodiscal pad what to do?
recoil back to postion
Why allows for the superior capsule to be lax in the upper TMJ?
the lack of ligaments
Which Trigeminal Cranial Nerve innervates Temporalis, Lateral Pterygoid, Medial Pterygoid and Messeter?
What muscle is parallel to Masseter?