Lecture 24: Infratemporal Fossa Flashcards
Slicing: mastication
sharp edges coming together or shearing past each other
Eating meat
Grinding: mastication
Sliding of rough or textured surfaces
Circular, side to side movements
Temporomandibular joint
formed by the condyle (head) of the mandible
and the mandibular (glenoid) fossa of the temporal bone
Functions of lateral ligament in TMJ (2)
Prevent lateral displacement of condyle
Prevent excessive Rostral displacement when mouth is open
Movement prevented by retroarticular process in TMJ
Prevent posterior/caudal displacement
Movement prevented by joint capsule, surrounding muscles and proper use of mandible: TMJ
Ventral displacement (so condyle doesn’t pop out)
Are anterior/Rostral movements at TMJ restricted
No
2 types of lateral excursions of mandible
Ipsilateral
Contralateral
Ipsilateral excursion (chewing) of mandible
lateral movement of anterior mandible and tooth due to muscles that move on the same side (i.e. lateral pterygoid and medial pterygoid)
Contralateral excursion of mandible
Anterior mandible and tooth row move opposite side from muscle
How are lateral movements of anterior mandible and tooth row produced
Retractors of same side = Ipsilateral
Protruders of opposite side = Contralateral
4 muscles of mastication
Temporalis
Masseter
Medial pterygoid
Lateral pterygoid
Muscles of mastication all cross ______ and are innervated by what nerve
TMJ
V3/mandibular nerve
Temporalis: OINA (2 actions)
O - temporal fossa
I - coronoid process
N - V3
A - bilateral jaw closing
Unilateral: some retraction of mandible
Masseter: OINA (2 actions)
O - zygomatic arch
I - Masseteric fossa and angular process of mandible
N - V3
A - bilateral jaw closing
Unilateral - superficial fibers protract mandible, deep fibers retract mandible
Medial pterygoid: OINA
O - pterygopalatine fossa
I - medial surface of mandibular ramus and angular process
N - V3
A - bilateral jaw closing
Unilateral - protraction
Lateral pterygoid: OINA
O - pterygopalatine fossa
I - Capsule of TMJ and articular disk
N - V3
A - control position of articular disk during jaw movement
Primary mastication functions of carnivores and Omnivores
Slicing and crushing
Largest jaw closer muscle in carnivores
Temporalis
Which muscles predominate in herbivores
Masseter and medial pterygoid
Zygomatic arch: carnivores vs herbivores
Carnivores = wide
Herbivores = less prominent
TMJ: herbivores vs carnivores
Carnivores = more hinge like joint to restrict unilateral protraction and retraction
Herbivores = flatter, less restricted to unilateral protraction and retraction
Mylohyoid: OINA
O - medial aspect of mandibular body
I - midline rap he with fibers from opposite muscle and basihyoid (muscular hammock)
N - mylohyoid nerve from V3
A - raise floor of oral cavity to support tongue and draw basihyoid Rostrally
Digastric: unique feature
Digastric = 2 bellies
Split muscle with caudal and Rostral bellies separated by tendon
Digastric: OIN(2)A
O - paracondylar process
I - ventral and medial aspect of mandible
N - Rostral: mylohyoid nerve from V3
Caudal: facial nerve
A - active depression of mandible to open jaw
Unique innervation in Digastric (2)
Rostral = mylohyoid nerve
Caudal = facial nerve
Occipitomandibularis: definition, species
Accessory belly of caudal Digastric found in horses
Mandibular nerve: types of innervation
Motor - muscles of mastication
Sensory - skin and mucosa of mandibular region (ear, cheek, jawline, lower lip, tongue, mandibular teeth)
Sensory branches of mandibular nerve (5)
Buccal
Auriculotemporal
Inferior alveolar
Mylohyoid
Lingual
Buccal nerve: branch of mandibular
From skin of cheek and underlying oral mucosa
Auriculotemporal nerve: mandibular
Stuck underneath parotid tissue
Parts of external ear
Most of skin over Temporalis, masseter, zygomatic arch
Inferior alveolar nerve: mandibular
Enters mandibular foramen
Mandibular teeth
Mental nerve is branch of what nerve
Inferior alveolar
Mental nerve: mandibular branch
Branch of inferior alveolar
Exits mental foramen
From skin of chin
Mylohyoid nerve: mandibular nerve
Mostly motor to mylohyoid and Rostral Digastric muscles
Sensory to skin below mandibular body
Lingual nerve: mandibular
Parallel to inferior alveolar nerve
Sensory from anterior 2/3 of tongue and lingual mucosa
Special sensory and preganglionics from facial nerve
3 parts of maxillary artery
Mandibular
Pterygoid
Pterygopalatine
Inferior alveolar artery runs with what nerve
Inferior alveolar
Which nerve and artery art part of the mandibular portion of maxillary artery
Inferior alveolar
Middle meningela
Artery and nerve that’s part of pterygopalatine portion of maxillary
Buccal artery and buccal nerve from V3
