TMJ

Question 1

What type of joint is the TMJ?

Answer 1

modified hinge

Question 2

Label

Answer 2

Anteriorly is articular tubercle

posteriorly is post glenoid tubercle

Question 3

label

Answer 3

anteriorly is articular aminence

middle is articular tubercle

posteriorly is post glenoid tubercle

Question 4

Borders of mandibular fossa

Answer 4

Lateral: zygomatic process of temporal bone

Medial: spine of sphenoid bone

Anterior: articular eminence

Posterior: squamotympanic and petrotypanic fissures

Question 5

what passes through petrotympanic fissure?

Answer 5

chorda tympani

Question 6

What’s more medial: squamotympanic fissure or petrotympanic fissure?

Answer 6

pertrotympanic fissure is the more medial half

Question 7

How are the condyles of the mandible formed?

Answer 7

intramembranous ossification

Question 8

What attaches to external oblique line?

Answer 8

depressor anguli oris

Question 9

What is found on each side (laterally) of the mental spine of the interior mandible?

Answer 9

digastric fossae

Question 10

What attaches to the digastric fossae?

Answer 10

origin of the anterior belly of the digastric

Question 11

What attaches to the mental spine?

Answer 11

genioglossus muscle attaches to superior aspect of mental spine

geniohyoid attaches to lower aspect

Question 12

What passes through mandibular canal?

Answer 12

inferior alveolar nerve and artery

Question 13

what passes through mental foramen?

Answer 13

cutaneous branches of inferior alveolar nerve and artery

Question 14

What attaches to the lingula?

Answer 14

sphenomandibular ligament

Question 15

what runs along mylohyoid sulcus/groove and where is it located?

Answer 15

runs downward and forward from inferior border of mandibular foramen

nerve to mylohyoid muscle runs along it

Question 16

What’s the shape of the articualr disc?

Answer 16

biconcave

Question 17

Where are superior and inferior lamellae found?

Answer 17

inner periphery of articulator capsule

Question 18

primary composition of superior and inferior lamellae

Answer 18

Superior is ELASTIC

inferior is COLLAGEN

Question 19

two regions of joint capsule of TMJ

Answer 19

capsular ligament and lateral/temporomandibular ligament

Question 20

what does the capsular ligament prevent?

Answer 20

excessive lateral movement and posterior dislocation

Question 21

what does lateral/temporomandibular ligament prevent?

Answer 21

excessive lateral movement and posterior dislocation

Question 22

attachments of stylomandibular ligament

Answer 22

styloid process to angle of mandible

Question 23

function of stylomandibular ligament

Answer 23

limits protrusion

Question 24

sphenomandibular attachments

Answer 24

from spine of sphenoid to lingula of mandible

Question 25

function of sphenomandibular ligament

Answer 25

supports weight of mandible prevents excessive lateral movement of mandible

Question 26

fulcrum of elevation and depression of the mandible

Answer 26

approx. at mandiblar foramen

Question 27

Locations of hinge movement and gliding at TMJ

Answer 27

hinge at lower joint compartment gliding/translation at upper joint compartment

Question 28

attachments of temporalis muscle

Answer 28

temporal fossa tip of coronoid process, ramus of mandible

Question 29

action of temporalis muscle

Answer 29

elevation, retrusion of mandible (bilaterally) also holds resting position of mandible

Question 30

innervation of temporalis muscle

Answer 30

deep temporal branches

Question 31

attachments of masseter muscle

Answer 31

outer and inner surfaces of zygomatic bone and arch angle and lateral surface of ramus of mandible

Question 32

action of masseter muscle

Answer 32

bilateral elevation and protrusion of the mandible

Question 33

innervation of masseter muscle

Answer 33

masseteric nerve

Question 34

attachments of lateral pterygoid muscle

Answer 34

Sup head: greater wing of sphenoid Inf head: lateral pterygoid plate both: capsule, disc, condyle

Question 35

action of lateral pterygoid muscle

Answer 35

bilateral mandibular depression (only muscle of mastication that does this), protracts mandible

Question 36

innervation of lateral pterygoid muscle

Answer 36

lateral pterygoid nerve

Question 37

attachments of medial pterygoid muscle

Answer 37

lateral pterygoid plate, tuberoisity of maxilla medial ramus of mandible, inferior to mandibular foramen

Question 38

action of medial pterygoid muscle

Answer 38

bilateral elevation, protrusion

Question 39

innervation of medial pterygoid muscle

Answer 39

medial pterygoid nerve

Question 40

what gives sensory information to TMJ?

Answer 40

auriculotemporal nerve (also small anterior portion by masseteric branches of V3) pain from posterior and posterolateral regions of capsule retrodiscal inferior lamella contains proprioceptive mechanoreceptors for condyle movement

Question 41

what gives blood supply to TMJ?

Answer 41

articular branches from superficial temporal artery also arterial twigs from muscular branches of maxillary artery for anterior aspect