TMJ Flashcards
what type of joint is TMJ?
Hinge joint
three components of TMJ
articular eminence and tubercles or temporal bone, mandibular fossa of temporal bone, condyle of mandible.
what passes through the petrotympanic fissure?
chorda tympani
what separates the mandibular fossa of the squamous portion of the temporal bone from the tympanic plate of the temporal bone
squamotympanic fissure
medial half of the squamotympanic fissure becomes what?
petrotympanic fissure
articular surface of condyle covered by what?
dense fibrous tissue with isolated groups of chondrocytes
what kind of bone formation used to form condyle/mandibular bones?
intramembranous ossification
what attaches at the external oblique line?
depressor anguli oris
What muscle is attached to the upper aspect of the mental spine?
genioglossus
What muscle attaches to the lower aspect of mental spine?
geniohyoid
mandibular canal carries what?
alveolar nerve and artery
What is the tonguelike projection of bone guardiang the superoanterior border of mandibular foramen?
lingula
What muscle attaches to the Lingula?
sphenomandibular ligament
internal oblique line divides into what two regions?
retromolar triangle and retromolar fossa
disc is attached to the
inner periphery of the articular
capsule by what?
superior and inferior sheets or lamellae
Lamellae blend with what?
capsular ligament
superior lamella is mostly what?
elastic
inferior lamella is mostly what?
collagen
what are the two intrinsic ligaments of the TMJ, and what do they do?
capsular and lateral ligament or tmj ligament. prevent excessive lateral movement and posterior dislocation.
what are the 2 extrinsic ligaments?
stylomandibular and sphenomandibular.
stylomandibular attaches where and limits what?
styloid process to the angle of the mandible. limits protrusion
sphenomandibular
spine of sphenoid to the lingula of the mandible. supports weight of the mandible, and prevents excessive lateral movement of mandible.
movement of the mandible includes what?
hinge and gliding movement
where does hinge take place?
in lower joint compartment
where does gliding take place?
in upper compartment
What is the temporalis muscle innervated by?
deep temporal branches
attachments of temporalis muscle
temporal fossa, tip of coronoid process, ramus of mandible
action of temporalis muscle
bilateral: elevation, retrusion of mandible. unilateral: ipsilateral deviation. holds resting position of mandible.
innervation of masseter muscle
masseteric nerve
attachments of masseter muscle?
outer and inner surfaces of the zygomatic bone and arch, angle and lateral surface of ramus of mandible.
action of masseter muscle?
bilat: elevation, protrusion of mandible. uni: ipsilateral deviation
Innervation of lateral pterygoid muscle
lateral pterygoid nerve
attachments of lateral pterygoid muscle
sup head: greater wing of sphenoid. inf head: lateral pterygoid plate. both: capsulee, disc, condyle
action of lateral pterygoid muscle?
bilat: depresses, protracts mandible. uni: contralateral deviation
innervation of medial pterygoid muscle?
medial pterygoid muscle
action of medial pterygoid muscle
bilat: elevation,protrusion. uni: contralateral deviation
attachments of medial pterygoid ?
lateral pterygoid plate, tuberosity of maxilla. medial ramus of mandible, inferior to mandibular foramen
most of the nerve supply to TMJ supplied by what?
sensory articular branches of auriculotemporal nerve
small anterior portion of TMJ is supplied by what?
masseteric branches of V3
what does the posterior regions of joint capsule contain nerve wise?
free nerve endings conducting pain impulses
retrodiscal inferior lamella contain what ?
prprioreceptive mechanoreceptors that detect condylar movement and position.
Articular branches arise from the___________________ artery to supply most of the joint.
superficial temporal artery
there are small arterial twigs from muscular branches of the ________ artery that supply the anterior aspect of the joint.
maxillary
