Teeth and Mastication 2 Flashcards
1
Q
What is mastication?
A
- chewing to break food down prior swallowing
2
Q
What is the difference between carnivore herbivores’ and omnivores?
A
- Carnivore - carnassial teeth, notched, trap food for effective cutting, rely on canines for tearing
- Herbivores - well- developed cutting ridges and horizontal movement of chewing
- omnivores - variable
3
Q
Mastication mechanics - What are the process’ and what joint do they articulate at (the jaw)?
A
- coronoid process (on top)
- condylar process (on bottom) - articulates at the temporomandibular joint (TMJ)
4
Q
What components make up the canine jaw?
A
- coronoid process
- ramus
- condylar process
- masseteric fossa
- body
5
Q
What is the temporomandibular joint?
A
- articulation between condylar process of mandible and mandibular process of the skull
6
Q
Jaw articulation involves what 2 things?
A
- TMJ
- Mandibular symphysis
7
Q
What is the mandibular process?
A
- Fibrous joint between left and right 1/2s of the mandible
- allows fine commentary adjustment - precise occlusion
- independent rotation of each mandibular bone - move apart
8
Q
What are the muscles of the jaw?
A
- masseter muscle
- temporal muscle
- pterygoid muscle
- digastric muscle
9
Q
Digastricus muscle:
- function
- origin
- insertion
- innervation
A
- function - opening of jaws
- origin - paracondylar process of the occipital bone
- insertion - at the angle of the mandible
- innervation - branches of facial nerve and trigeminal nerve
10
Q
Masseter muscle:
- function
- origin
- insertion
A
- Function - closing of jaw - contraction protrudes jaw
- origin - maxillary region - zygomatic arch
- insertion - caudal mandible
11
Q
Temporal muscle:
- function
- origin
- insertion
A
- Function - closing of the jaw - pulls mandible dorsally (also rostrally and/or caudally)
- origin - lateral surface - cranium
- Insertion - coronoid process
12
Q
Lateral pterygoid muscle:
- function
- origin
- insertion
A
- Function - closes jaw - protrudes jaw
- origin - pterygopalatine part of skull
- inserts - lateral mandible
13
Q
Medial pterygoid muscle:
- function
- origin
- insertion
A
- Function - closes jaw (one-sided contraction)
- origin - pterygopalatine part of skull
- inserts - medial mandible
14
Q
What muscles are involved in lateral translation of the mandible?
A
- masseter muscle and contralateral medial and lateral pterygoids
15
Q
Describe herbivores mastication mechanics?
A
- large masseter and pterygoid for extensive chewing - lateral movement
- limited digastricus muscle
- horse - muscle insertion site for masseter is large - snaps shut
