Lecture 12 - Mastication Flashcards
What attaches to the angle of the mandible?
muscles
What passes through the mandibular notch?
neurovasculature
What is the hole on the chin called?
mental foramen
What two parts make up the condylar process of the mandible?
head and neck of mandible
Which process articulates with the temporomandibular joint?
condylar process
What are the two processes on the ramus of the mandible?
condylar and coronoid process
How many teeth does a typical adult have?
32 (if wisdom teeth are in tact)
What are the 4 mandibular dentitions?
- incisors
- canines
- premolars
- molars
How many pairs of incisors are there?
4
How many pairs of canines are there?
2
How many pairs of premolars are there?
4
How many pairs molars are there?
6
What sits within the temporomandibular joint?
articular disk
What is the function of the articular disk?
reduces friction in the TMJ and facilitates movement
What are the 2 bones of the temporomandibular joint?
mandible and temporal bone
What part of the mandible contributes to the TMJ?
head
What 2 parts of the temporal bone contributes to the TMJ?
mandibular fossa and articular tubercle
What are the 3 ligaments that support the TMJ?
- lateral ligament
- stylomandibular
- sphenomandibular
Which ligament is a thickening of the joint capsule?
lateral ligament
What kind of joint is the TMJ?
modified synovial hinge joint
What 3 movements happen at the TMJ?
rotational (saggital + horizontal plane) and anteroposterior translational
What axis does rotational movement in saggital plane of the TMJ happen?
transverse axis
What axis does anteroposterior translational movement of the TMJ happen?
no axis
What axis does the rotational movement in horizontal plane of the TMJ happen?
vertical axis
Protrusion is ___ translation of the mandible.
anterior
Retraction is ___ translation of the mandible.
posterior
Depression is ___ rotation about the transverse axis.
downward
What 2 actions happen during opening of the mouth?
protrusion and depression
What 2 actions happen during closing of the mouth?
retraction and elevation
What are the articular surfaces of the head of the mandible and mandibular fossa lined with?
fibrocartilage
What is the TMJ joint cavity filled with?
synovial fluid
When opening the mouth >15 degrees, the articular disc and head of mandible slide anteriorly beneath the ___.
articular tubercle
When does TMJ dislocation occur?
when the head of the mandible passes anterior to the articular tubercle
What can TMJ dislocation be related to?
excessive contraction of the lateral pterygoid muscle
What actions can cause a TMJ dislocation?
big yawn, trying to eat a huge sandwich
What kind of dislocation is uncommon?
posterior dislocation
What are the 4 muscles of mastication?
masseter, temporalis, lateral pterygoid, medial pterygoid
What is the action of the masseter muscle?
elevation and protrustion
What is the innervation of the masseter?
CN V3 (masseteric nerve)
What is the attachment of the masseter?
zygomatic arch to angle / lateral surface of ramus of mandible
What is the action of the temporalis muscle?
elevation and retraction
What is the attachment of the temporalis?
temporal fossa -> coronoid process of mandible
What is the innervation of the temporalis?
CN V3 (deep temporal nerves)
What is the action of the lateral pterygoid?
bilateral: protrusion
unilateral: lateral movement of contralateral side
What is the attachment of the lateral pterygoid?
lateral surface of lateral pterygoid plate -> condylar process of mandible and articular disc of TMJ
What is the innervation of the lateral pterygoid?
CN V3 lateral pterygoid nerve
What is the action of the medial pterygoid?
elevation and protrustion
What is the attachment of the medial pterygoid?
medial surface of lateral pterygoid plate and maxillary tuberosity -> angle and medial surface of ramus of mandible
What is the innervation of the medial pterygoid?
CN V3 lateral pterygoid nerve
What nerve provides motor innervation to the muscle of mastication?
mandibular division of the trigeminal nerve
What foramen does CN V3 pass through to enter the infratemporal fossa?
the foramen ovale
What is the temporal fossa connected inferiorly with?
the infratemporal fossa
Where is the infratemporal fossa located?
deep to the ramus of the mandible
What are the 6 boundaries of the temporal fossae?
- Lateral: ramus of the mandible
- Medial: lateral pterygoid plate
- Anterior: posterior aspect of maxilla
- Posterior: tympanic part of temporal bone + styloid process
- Superior: inferior surface of greater wing of sphenoid
- Inferior: attachment of medial pterygoid (angle of mandible)
Adult dentition follows the same pattern of 8 teeth in each ___ of the mouth.
quadrant
Where does the mandibular canal start and end?
mandibular foramen to mental foramen
Where does maxillary neurovasculature travel through?
maxillary sinus
Where does mandibular neurovasculature travel?
mandibular canal
What nerve innervates the gums?
lingual nerve
What nerve innervates mandibular teeth and gums?
inferior alveolar nerve
What does the mental nerve innervate?
gums and skin of chin
What do the superior alveolar nerves innervate?
maxillary teeth
What artery branches into the inferior alveolar artery?
maxillary
What are the 5 superficial structures of the ITF?
Superficial temporal a. + v.
Deep temporal a. + n.
Lateral pterygoid muscle
(superior & inferior heads)
Inferior alveolar a. + n.
Lingual n.
What are the 5 deep structures of the ITF?
- superficial temporal artery and vein
- deep temporal nerve
- medial pterygoid muscle
- lingual nerve
- maxillary artery
