Occlusion I - Anatomy of Mastication

Define mastication

act of chewing accomplished by coordinated activity of both skeletal hard tissue and soft tissue components

What is the masticatory system?

structures involved in chewing, speaking, and swallowing

What are the 4 major components of the masticatory system?

skeletal component, ligament component, articular component, muscular component

All of the following make up the skeletal component of the masticatory system EXCEPT one. Which one is the exception?

A) maxilla

B) mandible

C) temporal bone

D) parietal bones

D) parietal bones

All of the following ligaments make up the ligament component of the masticatory component EXCEPT one. Which one is the exception?

A) collateral ligaments

B) capsular ligaments

C) temporamandibular ligaments

D) lateral collateral ligaments

D) lateral collateral ligaments

What are the ligaments of the masticatory system?

collateral ligaments, capsular ligaments, temporoamandibular ligaments

What type of joint is the TMJ?

A) ginglymoid

B) arthrodial

C) ginglymoarthrodial

D) neither ginglymoid nor arthrodial

C) ginglymoarthrodial

What are the main muscles of the masticatory system?

masseter, temporalis, medial pterygoids, lateral pterygoids

All of the following are considered the main muscles of mastication EXCEPT one. Which one is the exception?

A) medial pterygoid

B) lateral pterygoid

C) stylohyoid

D) masseter

E) temporalis

C) stylohyoid

The condyle of the mandibular articulates with fossa on the temporal bone?

mandibular fossa

What are the parts of the articular component of the TMJ?

mandibular condyle, mandibular fossa, articular disk

All of the following are parts of the articular component of the TMJ EXCEPT one. Which one is the exception?

A) mandibular condyle

B) mandibular fossa

C) articular disk

D) mandibular coronoid process

D) mandibular coronoid process

The disc is tightly bound to the condyle by what ligaments?

A) collateral ligaments

B) capsular ligaments

C) lateral + medial discal ligaments

D) temporomandibular ligaments

C) lateral + medial discal ligaments

What is the movement of the condyle-articular disc complex?

A) hinge

B) gliding

C) both hinge and gliding

A) hinge

What is the movement of the condylar-articular disc complex on the mandibular fossa?

A) hinge

B) gliding

C) both hinge and gliding

B) gliding

True/False: the muscles of elevation help stabilize the TMJ

True

What is the function of the medial and lateral collateral ligaments?

A) divide joint into superior + inferior joint cavities / restrict movement of disk away from the condyle

B) resists medial, lateral, + inferior forces / provides proprioception

C) limits normal rotational opening movement

D) limits posterior movement of condyle and disk

A) divide joint into superior + inferior joint cavities / restrict movement of disk away from the condyle

What are the functions of the capsular ligament?

A) divide joint into superior + inferior joint cavities / restrict movement of disk away from the condyle

B) resists medial, lateral, + inferior forces / provides proprioception

C) limits normal rotational opening movement

D) limits posterior movement of condyle and disk

B) resists medial, lateral, + inferior forces / provides proprioception

What ligament surrounds the entire TMJ?

A) collateral ligaments

B) capsular ligament

C) temporoamandibular ligament

D) discal ligaments

B) capsular ligament

What is the function of the outer oblique portion of the temporomandibular ligament?

A) divide joint into superior + inferior joint cavities / restrict movement of disk away from the condyle

B) resists medial, lateral, + inferior forces / provides proprioception

C) limits normal rotational opening movement

D) limits posterior movement of condyle and disk

C) limits normal rotational opening movement

What is the function of the inner horizontal portion of the temporomandibular ligament?

A) divide joint into superior + inferior joint cavities / restrict movement of disk away from the condyle

B) resists medial, lateral, + inferior forces / provides proprioception

C) limits normal rotational opening movement

D) limits posterior movement of condyle and disk

D) limits posterior movement of the condyle and disk

What are accessory ligaments of the masticatory system?

stylomandibular and sphenomandibular ligament

All of the following are accessory ligaments of the masticatory system EXCEPT one. Which one is the exception?

A) collateral ligament

B) stylomandibular ligament

C) sphenomandibular ligament

A) collateral ligament

What is the function of the stylomandibular ligament?

A) limits excessive protrusion of the jaw

B) prevents excessive inferior movements of mandible

C) encompasses the TMJ

D) limits posterior movement of the condyle and disk

A) limits excessive protrusion of the jaw

What is the function fo the sphenomandibular ligament?

A) limits excessive protrusion of the jaw

B) prevents excessive inferior movements of mandible

C) encompasses the TMJ

D) limits posterior movement of the condyle and disk

B) prevents excessive inferior movements of mandible

What are other important muscles in the head/neck region?

digastric, buccinator, pharyngeal constrictors

What is the origin of the temporalis?

A) temporal fossa

B) zygomatic arch

C) pterygoid fossa on sphenoid bone

D) outer surface of lateral pterygoid plate

E) infratemporal surface of the greater wing of the sphenoid

A) temporal fossa

What is the origin of the masseter?

A) temporal fossa

B) zygomatic arch

C) pterygoid fossa on sphenoid bone

D) outer surface of lateral pterygoid plate

E) infratemporal surface of the greater wing of the sphenoid

B) zygomatic arch

What is the origin of the medial pterygoid?

A) temporal fossa

B) zygomatic arch

C) pterygoid fossa on sphenoid bone

D) outer surface of lateral pterygoid plate

E) infratemporal surface of the greater wing of the sphenoid

C) pterygoid fossa on sphenoid bone

What is the origin of the inferior lateral pterygoid?

A) temporal fossa

B) zygomatic arch

C) pterygoid fossa on sphenoid bone

D) outer surface of lateral pterygoid plate

E) infratemporal surface of the greater wing of the sphenoid

D) outer surface of lateral pterygoid plate

What is the origin of the superior lateral pterygoid?

A) temporal fossa

B) zygomatic arch

C) pterygoid fossa on sphenoid bone

D) outer surface of lateral pterygoid plate

E) infratemporal surface of the greater wing of the sphenoid

E) infratemporal surface of the greater wing of the sphenoid

What is the insertion of the temporalis?

A) coronoid process and anterior portion of ramus

B) lateral aspect of lower border of the mandibular ramus

C) medial surface of mandibular angle

D) neck of condyle and TMJ capsule

E) articular capsule, articular disk, neck of condyle

A) coronoid process and anterior portion of ramus

What is the insertion of the masseter?

A) coronoid process and anterior portion of ramus

B) lateral aspect of lower border of the mandibular ramus

C) medial surface of mandibular angle

D) neck of condyle and TMJ capsule

E) articular capsule, articular disk, neck of condyle

B) lateral aspect of lower border of the mandibular ramus

What is the insertion of the medial pterygoid?

A) coronoid process and anterior portion of ramus

B) lateral aspect of lower border of the mandibular ramus

C) medial surface of mandibular angle

D) neck of condyle and TMJ capsule

E) articular capsule, articular disk, neck of condyle

C) medial surface of mandibular angle

What is the insertion of the inferior lateral pterygoid?

A) coronoid process and anterior portion of ramus

B) lateral aspect of lower border of the mandibular ramus

C) medial surface of mandibular angle

D) neck of condyle and TMJ capsule

E) articular capsule, articular disk, neck of condyle

D) neck of condyle and TMJ capsule

What is the insertion of the superior lateral pterygoid?

A) coronoid process and anterior portion of ramus

B) lateral aspect of lower border of the mandibular ramus

C) medial surface of mandibular angle

D) neck of condyle and TMJ capsule

E) articular capsule, articular disk, neck of condyle

E) articular capsule, articular disk, neck of condyle

What is the innervation of the temporalis?

A) V3, deep temporal nerve

B) V3, masseteric nerve

C) V3, medial pterygoid branch

D) V3, lateral pterygoid nerve

A) V3, deep temporal nerve

What is the innervation of the masseter?

A) V3, deep temporal nerve

B) V3, masseteric nerve

C) V3, medial pterygoid branch

D) V3, lateral pterygoid nerve

B) V3, masseteric nerve

What is the innervation of the medial pterygoid?

A) V3, deep temporal nerve

B) V3, masseteric nerve

C) V3, medial pterygoid branch

D) V3, lateral pterygoid nerve

C) V3, medial pterygoid branch

What is the innervation of the lateral pterygoid?

A) V3, deep temporal nerve

B) V3, masseteric nerve

C) V3, medial pterygoid branch

D) V3, lateral pterygoid nerve

D) V3, lateral pterygoid nerve

What is the action of the temporalis?

A) elevates mandible

B) elevates + protrudes mandible

C) protrudes and depresses mandible

D) active during power stroke

A) elevates mandible

What is the action of the masseter?

A) elevates mandible

B) elevates + protrudes mandible

C) protrudes and depresses mandible

D) active during power stroke

A) elevates mandible

What is the action of the medial pterygoid?

A) elevates mandible

B) elevates + protrudes mandible

C) protrudes and depresses mandible

D) active during power stroke

B) elevates + protrudes mandible

What is the action of the inferior lateral pterygoid?

A) elevates mandible

B) elevates + protrudes mandible

C) protrudes and depresses mandible

D) active during power stroke

C) protrudes and depresses mandible

What is the action of the superior lateral pterygoid?

A) elevates mandible

B) elevates + protrudes mandible

C) protrudes and depresses mandible

D) active during power stroke

D) active during power stroke

What is the origin of the anterior belly of the digastric?

A) fossa on lingual surface of mandible

B) angle of mandible

C) mastoid notch

D) mandibular fossa

A) fossa on lingual surface of mandible

What is the origin of the posterior belly of the posterior belly of the digastric?

A) fossa on lingual surface of mandible

B) angle of mandible

C) mastoid notch

D) mandibular fossa

C) mastoid notch

What is the insertion of the anterior belly of the digastric?

A) intermediate tendon attached to the hyoid

B) temporal fossa

C) angle of mandible

D) fossa on lingual surface of mandible

A) intermediate tendon attached to the hyoid

What is the insertion of the posterior belly of the digastric?

A) intermediate tendon attached to the hyoid

B) temporal fossa

C) angle of mandible

D) fossa on lingual surface of mandible

A) intermediate tendon attached to the hyoid

What is the function of the digastric?

A) elevates mandible

B) depresses mandible

C) protrudes mandible

D) retrudes mandible

B) depresses mandible

True/False: ligament participate in normal TMJ function

False

True/False: ligament stretch

False

True/False: the articular surfaces of the TMJ must be maintained in constant contact

True

True/False: contact of the articular surfaces of the TMJ are produced teeth occlusion

False

True/False: contact of the articular surfaces of the TMJ are produced by the muscles of mastication

True