Muscles of Mastication

Question 1

Orbicularis Oris

Answer 1

Origin: Fibers of other fascial muscles
Insertion: skin at angle of mouth (modiolus)
Function: closes and protrude’s lips

Question 2

Zygomaticus major

Answer 2

Origin: zygomatic bone
Insertion: orbicularis oris, depressor anguli oris, modiolus
Function: draws angle of mouth laterally and upward

Question 3

Zygomaticus minor

Answer 3

Origin: zygomatic bone
Insertion: subcutaneous tissue of upper lip, modiolus
Function: draws upper lip outward and upward

Question 4

Levator labii superioris

Answer 4

Origin: zyg, frontal process of maxilla, inferior margin of orbit
Insertion: skin of upper lip
Function: raises upper lip and moves it forward

Question 5

Levator labii superioris alaeque nasi

Answer 5

Origin: frontal process of maxilla
Insertion: alar cartilage and levator labii superioris
Function: raises upper lip

Question 6

Levator anguli oris

Answer 6

Origin: canine fossa of maxilla
Insertion: angle of the mouth, modiolus
Function: raises angle of the mouth

Question 7

Mentalis

Answer 7

Origin: circular area that extends from central incisor to the canine eminence, on the anterior lateral mandible
Insertion: into the skin, chin and lip
Function: tightens the lower lip

Question 8

Buccinator

Answer 8

Origin: buccal alveolar processes of maxilla and mandible
Insertion: orb oris to anterior, modiolus, and forms pterygomandibular raphe posteriorly as it inserts into the superior constrictor
Function: compresses cheeks

Question 9

Depressor anguli oris

Answer 9

Origin: lower border of the lateral body of the mandible, just above platysma
Insertion: risorius, orb oris, modiolus
Function: draws angle of mouth downward and laterally

Question 10

Risorius

Answer 10

Origin: fascia of masseter
Insertion: modiolus, skin at angle of mouth
Function: retracts angle of the mouth

Question 11

Platysma

Answer 11

Origin: fascia of pactoralis major and deltoid
Insertion: mandible inferior surface and skin of lower face
Function: depresses lower mandible

Question 12

Deep masseter

Answer 12

Origin: zygomatic arch
Insertion: lateral border of the ramus of mandible
Function: raises mandible

Question 13

Superficial masseter

Answer 13

Origin: zygomatic arch
Insertion: ramus of mandible
Function: raises mandible

Question 14

Temporalis

Answer 14

Origin: temporla fossa and temporal fascia
Insertion: mandible, coronoid process and anterior of ramus
Function: elevates and retracts mandible

Question 15

Medial pterygoid

Answer 15

Origin: medial surface of lateral pterygoid plate
Insertion: ramus and angle of the mandible, medial surface
Function: draws mandible forward, and aids in the closure of the mandible

Question 16

Superior lateral pterygoid

Answer 16

Origin: sphenoid bone, superior part of lateral pterygoid plate
Insertion: disc and capsule of the TMJ, neck of condyle
Function: draws mand forward, positions disc over head of condyle during movement, active only with elevator muscles (closure of mandible)

Question 17

Inferior lateral pterygoid

Answer 17

Origin: inferior part of the lateral pterygoid plate
Insertion:neck of condyle
Function: draws mandible forward

Question 18

sternocleidomastoid

Answer 18

Origin: upper and anterior manubrium superor and anterior medial third of clavicle
Insertion: lateral surface of mastoid process, nuccal line of occipital bone
Function: unilateral draws head to shoulder of same side and rotates head to opposite side, bilateral flexes head

Question 19

Digastric

Answer 19

Origin: anterior-lower border of anterior mandible lingual side, posterior-mastoid notch of temporal bone medial to mastoid process
Insertion: hyoid bone, the anterior body originates from the intermediate tendon
Function: elevates hyoid, depresses mandible

Question 20

Stylohyoid

Answer 20

Origin: styloid process of temporal bone
Insertion: body of hyoid
Function: elevates hyoid

Question 21

Mylohyoid

Answer 21

Origin: interior surface of mandible, mylohyoid line, from last molar to mandibular symphasis
Insertion: body of hyoid
Function: raises floor of mouth, elevates hyoid, depresses mandible

Question 22

Geniohyoid

Answer 22

Origin: inferior mental spine of mandible, genial tubercle
Insertion: tongue and anterior body of hyoid bone
Function: elevates hyoid, depresses mandible

Question 23

Superior constrictor of pharynx

Answer 23

Origin: lower 1/3 of posterior border of medial pterygoid plate, pterygoid hammulus, posterior end of mylohyoid line of mandible
Insertion: posteriorlateraly and medially to a medial raphe with the contralateral muscle and the pharyngeal tubercle on the base of the skull
Function: on constriction, will push food into alimentary canal, on constriction will close off the nasopharynx to prevent food or liquid from entering the nasopharynx

Question 24

Genioglossus

Answer 24

Origin: mental tubercle or spine, on the inner surface of the mandible
Insertion: the tongue and the body of the hyoid bone, spreading fanlike from origin
Function: moves tongue

Question 25

Muscle of Uvula

Answer 25

Origin: posterior nasal spine and the posterior surface of the palatine aponeurosis Insertion: back to the levator muscle and the tip of the uvula into the mucous membrane Function: moves uvula to close off the nasopharynx

Question 26

Tensor Veli Palatini

Answer 26

Origin: medial pterygoid plate of the sphenoid Insertion: palatine aponeurosis (soft palate) Function: tenses the soft palate

Question 27

What do all of the mandibular depressor muscles have in common?

Answer 27

the hyoid bone

Question 28

What are the suprahyoid depressors of the mandible?

Answer 28

Mylohyoid, geniohyoid, and digastric muscles

Question 29

In an inferior alveolar nerve block, you will pierce the __________, go lateral to the ____________, and find the ____________ foramen. The _______________ will be your landmark.

Answer 29

1. superior connector 2. medial pterygoid muscle 3. mandibular 4. pterygomandibular raphe

Question 30

Platysma

Answer 30

Origin: over the pectoralis major and deltoid muscles Insertion: inferior border of the mandible and skin of lower face Function: draw the corners of the mouth down and aids in depression of the mandible