TMJ Lecture Flashcards
What type of joint is the TMJ?
Hinge Joint
What movements do the TMJ allow the Mandible to have?
Flexion/extension or elevation/depression of the mandible
How many articular discs does the TMJ have?
2 which creates 2 synovial cavities a superior and an inferior
What is the role of the Superior compartment of the TMJ?
to allow for protrude/retrude
What is the role of the Inferior compartment of the TMJ?
To allow for elevation/ depression
What is the name of the ligament that limits the range of motion?
Sphenomandibular ligament
Name the 6 components that make up the joint.
o Mandibular fossa of the temporal bone with articular cartilage
o Articular tubercle and postglenoid tubercle of the temporal bone
o Head of the mandible with articular cartilage
o Intraarticular disc- fibrocartilage
o Superior and inferior synovial cavities
o Articular capsule
What are the four muscles that act on the TMJ?
Temporalis, Masseter, Lateral Pterygoid, Medial Pterygoid
What is the definition of a TMJ dislocation?
When the head/condyle of the mandible is dislocated anterior to the articular tubercle
If someone has an Acute TMJ Dislocation what is the most likely cause?
Trauma
A patient presents with a TMJ dislocation which happens multiple times a year to the patient. What is the most likely cause of this?
Structural malformation of some sort
Where is the infratemporal fossa located?
- Deep and inferior to zygomatic arch
* Deep to ramus of mandible and posterior to maxilla
Describe the boundaries of the infratemporal fossa
o Lateral: Ramus of mandible o Medial: Lateral pterygoid plate o Anterior: Posterior aspect of maxilla o Posterior: Tympanic plate/ mastoid-styloid o Superior: Greater wing of sphenoid o Inferior: Angle of mandible
Name the 6 contents of the infratemporal fossa
o Inferior part of temporalis muscle o Lateral and medial pterygoid muscles o Maxillary artery o Pterygoid venous plexus o Nerves: mandibular, inferior alveolar, buccal, chorda tympani, lingual o Otic ganglion
Name the origin, Insertion, Action and nerve supply of the temporalis muscle.
Origin: Temporal Fossa
Insertion: Coronoid process
Action: Elevate mandible, closes jaw, retract protruded
mandible
Nerve Supply: CN VName the origin, Insertion, Action and nerve supply of the lateral pterygoid muscle.
Origin: Superior head (Greater Wing) Inferior Head
(Lateral pterygoid plate)
Insertion: Neck of the mandible
Action: Protrude mandible, depress chin, side to side
movement
Nerve Supply: CN V (Lateral Pyterigoid Nerve)
Name the origin, Insertion, Action and nerve supply of the medial pterygoid muscle.
Origin deep head: Lateral pterygoid plate, pyramidal
process of palatine bone
Origin Superficial Head: Tuberosity of Maxilla
Insertion: Ramus of Mandible
Action: Elevate, protrude mandible, close jaw
Nerve Supple: Middle Pterygoid Nerve
What is the relationship between the maxillary artery and the external Carotid?
It is a terminal branch of the External Carotid and arises posterior to the neck of the mandible
Where is the location of the 1st part of the artery?
It passes anterior deep to the neck of the mandibular condyle.
What are the 5 branches of the 1st part of the maxillary artery?
- Deep auricular artery
- Anterior tympanic artery
- Middle meningeal artery
- Accessory meningeal artery
- Inferior alveolar artery
Where would you find the 2nd part of the Maxillary artery?
It passes superficially to the lateral pterygoid muscle.
Name the 4 branches of the 2nd part of the Maxillary artery.
- Deep temporal artery
- Pterygoid artery
- Masseteric artery
- Buccal artery
Where is the 3rd part of the Maxillary artery found?
Through the pterygoidmaxillary fissure to enter the infratemporal fissure.
Name the 6 branches of the 3rd part of the maxillary artery.
- Posterior superior alveolar artery
- Infraorbital artery
- Descending palatine artery
- Artery of pterygoid canal
- Pharyngeal artery
- Sphenopalatine artery
What is the pathway the Mandibular nerve travels?
From trigeminal ganglion through foramen ovale to infratemporal fossa with trigeminal motor fibers
What are the 4 branches of the mandibular nerve?
auriculotemporal, inferior alveolar, buccal (sensory), lingual
Where does the auriculotemporal nerve arise from and what type of nerve fibers does it carry?
It arises from the mandibular nerve and carries postganglionic parasympathetic fibers from the otic ganglion to the parotid ganglion
What does the inferior alveolar nerve innervate and where does it get its fibers from?
The nerve to the mylohyoid branches off before it enters the mandibular foramen. it supplies all the mandibular teeth on the ipsilateral side.
Where does the Inferior Alveolar nerve end on the mandible?
Ends as mental nerve through mental foramen to lower lip, chin, vestibular gingiva of mandibular incisors
What is the main function of the lingual nerve?
Sensory to anterior 2/3 of tongue, floor of mouth, and lingual gingiva
What type of nerve fibers does the lingual nerve carry to the anterior 2/3rds of the tongue?
SVA exiting from the lingual nerva and chorda tympani courses with the proximal portions of the facial nerve
What type of nerve fibers does the lingual nerve carry to the submandibular and sublingual glands?
Parasympathetic Preganglion.
Where is the Chorda Tympani?
It is at the junction of the facial nerve and the lingual nerve.
What types of nerve fibers make up the Chorda Tympani?
SVA fibers for taste to the anterior 2/3 of tongue.
Preganglionic Parasympathetic to submandibular ganglion.
