MUSCLES OF MASTICATION (quick and dirty version)

Question 1

origin of masseter

Answer 1

zygomatic arch

Question 2

insertion of masseter

Answer 2

• lateral surface of ramus
• angle of the mandible

Question 3

action of masseter

Answer 3

• elevates the mandible
• provides the force for chewing
• superficial head aids in chewing

Question 4

origin of temporalis

Answer 4

temporal fossa and lateral surface of skull

Question 5

insertion of temporalis

Answer 5

coronoid process and anterior border of ascending ramus

Question 6

action of temporalis

Answer 6

retrusion

Question 7

origin of inferior lateral pterygoid

Answer 7

outer surface of the lateral pterygoid plate

Question 8

insertion of inferior lateral pterygoid

Answer 8

neck of condyle

Question 9

action of inferior lateral pterygoid

Answer 9

bilateral contraction: protrusion & depression
unilateral contraction: mediotrusive movement

Question 10

origin of superior lateral pterygoid

Answer 10

infratemporal surface of the greater sphenoid wing

Question 11

insertion of superior lateral pterygoid

Answer 11

disk, capsule, and neck of condyle

Question 12

action of superior lateral pterygoid

Answer 12

*inactive during mandibular opening
- active with elevator muscles (chewing or clenching)

Question 13

origin of medial pterygoid

Answer 13

pterygoid fossa

Question 14

insertion of medial pterygoid

Answer 14

medial surface of the mandibular angle

Question 15

action of medial pterygoid

Answer 15

• elevation
• protrusion
• unilateral contraction: mediotrusion

Question 16

what forms the muscular sling?

Answer 16

masseter and medial pterygoid

Question 17

what is the function of the suprahyoids?

Answer 17

elevate the hyoid bone and depress the mandible when the hyoid bone is fixed

Question 18

contraction of what muscles causes depression of the mandible?

Answer 18

• inferior lateral pterygoid
• digastric

Question 19

contraction of what muscles causes elevation of the mandible?

Answer 19

• masseter
• medial pterygoid
• temporalis
  (some sources also include superior lateral pterygoid)

Question 20

contraction of what muscles cause lateral movement?

Answer 20

inferior lateral pterygoid (opposite of direction of movement)

Question 21

contraction of what muscles causes protrusion?

Answer 21

• inferior lateral pterygoid
• masseter
• medial pterygoid

Question 22

contraction of what muscles causes retrusion?

Answer 22

temporalis