COMPLETE SOLUTION | 2025/2026 UPDATE | GRADED
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What muscles are elevator muscles and help close the jaw during mastication?
Answer - Masseter
Medial pterygoid
Temporalis
What muscles are depressor muscles and help open the jaw? Answer - Lateral
pterygoid
Suprahyoid (digastric)
What are the two components to the masseter muscle? Answer - Superficial
and deep masseter
What is the origin and insertion of the Masseter muscle? Answer - Origin - the
outer surface of the zygoma
Insertion - Lower boarder of the ramus
What is the action of the masseter muscle? Answer - Elevation of mandible
and aids in protrusion
What are the three components of the temporalis muscle? Answer - Anterior,
Middle and Posterior
,What is the origin and insertion of the temporalis muscle? Answer - Origin -
Temporal fossa and lateral surface of the skull
Insertion - Coronoid process and anterior ascending ramus
What is the action of the temporalis muscle? Answer - elevates and retrudes
the mandible
What is the origin and insertion of the medial pterygoid muscle? Answer -
Origin - pterygoid fossa
Insertion - medial surface of the mandibular angle
What is the action of the medial ptyergoid? Answer - Elevates the mandible,
aids in protrusion.
Acts like a sling with the masseter muscle.
If a unilateral contractions happens of the medial pterygoid, what do you get?
Answer - Medio-trusive movement.
One condyle translates while the other rotates.
Balancing side movement
What are the two components of the lateral ptyergoid? Answer - Superior and
Inferior
What is the origin and insertion of the superior lateral ptyergoid? Answer -
Origin - Infratemporal surface of the greater wing of the sphenoid bone
Insertion - Medial portion of the articular disc (30-40%), Neck of the condyle
,What is the origin and insertion of the inferior lateral ptyergoid? Answer -
Origin - outer surface of lateral pterygoid plate
Insertion - neck of condyle
What is the function of the lateral ptyergoid? Answer - Protrudes the mandible
Aids in opening or depressing the mandible
If you get a lateral ptyergoid spasm, which side of the mouth would you have
an interference? Answer - •Discludes the dentition on the affected side
(posterior)
•Causes premature contact of the anterior teeth on the contralateral side
What is the origin and insertion of the anterior belly of the suprahyoid digastric
muscle? Answer - •Origin
-lingual surface of mandible at the midline
•Insertion
-intermediate tendon on hyoid bone
•Innervated by the 5th cranial nerve
What is the origin and insertion of the posterior belly of the suprahyoid
digastric muscle? Answer - •Origin
-mastoid notch
•Insertion
-intermediate tendon on the hyoid bone
•Innervated by the 7th cranial nerve
What is the action of the suprahyoid digastric muscle? Answer - Action
-depresses the mandible
, -accessory opening muscle
Which biomechanic movement of the condyle is a "hinge" movement? Where
does it occur? Answer - Rotational movement
-occurs between the condyle and the disc
Which biomechanic movement of the condyle is a "gliding" movement? Where
does it occur? Answer - Translational movement
- occurs between the disc and the fossa
If one joint is not translating, The mandible will deviate to the __________ side
Answer - affected
A slight translation in the horizontal plane of the "working side" of the condyle
is known as _________ movement. Answer - Bennett Movement
-Bodily shift of the mandible in the direction of the working condyle
- Just stating that when the jaw is moving right, the mandibular body of the left
is is moving over the horizontal plan.
In a left lateral movement, the right condyle moves ________ and the left
condyle shifts in a ________ _______ direction Answer - - forward
- lateral posterior
In a left lateral movement, which side is the "working" side? Answer - Left
In a left lateral movement, which side is the "non-working" or "balancing side"
Answer - Right