Oral Anatomy: Function/Occlusion

Question 1

T/F: A compensating curve is used to create balanced occlusion for artificial teeth.

Answer 1

True

Question 2

Describe a working side (laterotrusive) movement.

Answer 2

The side of the mouth that the mandible moves to

Question 3

Descibe a nonworking side (mediotrusive) contact.

Answer 3

Contacts on the side away from which the mandible has moved

Question 4

_________ is the vertical overlapping of mandibular incisors by maxillary incisors.

Answer 4

Overbite

Question 5

_________ is the horizontal overlapping of mandibular incisors by maxillary incisors.

Answer 5

Overjet

Question 6

T/F: Angle’s classification is based on molars only.

Answer 6

False

Molars and canines

Question 7

What is the molar relationship that defines Class I occlusion?

Answer 7

MB cusp of max M1 occludes with MB groove of mand M1

Question 8

Where is the max canine occluding in a Class I relationship?

Answer 8

Max canine occludes between mand canine and PM1

Question 9

What is the difference between Division I and Division II Class II occlusion?

Answer 9

Division I - all max incisors proclined

Division II - max centrals retroclined, laterals proclined

Question 10

In Class II occlusion, the MB cusp of max M1 occludes _________ to the MB groove of mand M1.

Answer 10

mesially

canine also occludes more mesially

Question 11

In class III occlsuion, the MB cusp of M1 occludes _______ to the MB groove of mand M1.

Answer 11

distally

canine also occludes more distally

Question 12

What are the working cusps of maxillary and mandibular teeth?

Answer 12

Max lingual and mand buccal

functional cusps

Question 13

What do working cusps oppose?

Answer 13

central fossae and marginal ridges

Question 14

T/F: Working cusps are sharper than nonworking cusps.

Answer 14

False

Broader and rounder

Question 15

T/F: Nonworking cusps support the vertical dimension of the face.

Answer 15

False

Working cusps

Question 16

What do nonworking cusps oppose?

Answer 16

Embrasure spaces and grooves

Question 17

In ideal CO, every tooth in one arch contacts two teeth in the opposite arch except for which teeth?

Answer 17

Max 3rd molars and mand central incisors

Question 18

Where do the ML cusps of max molars teeth occlude?

Answer 18

In the central fossa of their counterpart

Question 19

Where do the DL cusps of max molars and the lingual cusps of max premolars occlude?

Answer 19

Distal marginal ridge of counterpart and mesial marginal ridge of distal tooth

Question 20

The mandible acts as a _______ lever.

Answer 20

class III

Question 21

Although there are a couple exceptions, where do most buccal cusps of mandibular posterior teeth occlude?

Answer 21

Mesial marginal ridge of maxillary counterpart and distal marginal ridge of mesial tooth

Question 22

Which cusp of mand molars occludes in the central fossa of their counterparts?

Answer 22

DB cusps

Question 23

Where does the distal cusp of mand M1 occlude?

Answer 23

Triangular fossa of max M1

Question 24

Where does the MB cusp of max molars occlude?

Answer 24

Buccal groove of counterpart

Question 25

Where does the DB cusp and oblique ridge of the max M1 occlude?

Answer 25

DB groove of mand M1 Because of the distal cusp of mand M1

Question 26

Where do the DL cusps of mand molars occlude?

Answer 26

Lingual groove of counterpart

Question 27

Which nonworking cusp in the mandible opposes nothing?

Answer 27

L cusp of PM1

Question 28

_________ is the most anterior and superior position of the condyles.

Answer 28

Centric relation

Question 29

What is the terminal hinge position?

Answer 29

Position of the condyles in CR

Question 30

______ is a tooth-guided position. ______ is a ligament-guided position.

Answer 30

CO; CR

Question 31

T/F: During swallowing, the mandible meets the maxilla in centric occlusion.

Answer 31

True

Question 32

Posselt’s envelope of motion illustrates the mandible’s motion in which planes?

Answer 32

Sagittal, horizontal, frontal

Question 33

T/F: The side that the mandible moves to is the working side.

Answer 33

True

Question 34

The ____________ occurs during lateral excursive movements in which the working side condyle shifts laterally.

Answer 34

Bennett movement

Question 35

Protrusive movements are caused by contraction of _______________.

Answer 35

Both lateral pterygoids

Question 36

What muscle causes a lateral excursive movement?

Answer 36

Contraction of the lateral pterygoid on the non working side

Question 37

In which directions does the non working condyle move during a lateral excursive?

Answer 37

Anteriorly and medially

Question 38

Which muscles of mastication work for retrusion of the mandible? Protrusion?

Answer 38

Retrusion - temporalis and masseter Protrusion - Medial and lateral pterygoid

Question 39

Which is the only MoM that depresses the mandible?

Answer 39

Lateral Pterygoid

Question 40

All MoM are innervated by ______.

Answer 40

V3

Question 41

Which are the 5 suprahyoid muscles and how are they innervated?

Answer 41

1. Anterior digastric - V3 2. Posterior digastric - VII 3. Mylohyoid - V3 4. Geniohyoid - C1 via XII 5. Stylohyoid - VII

Question 42

T/F: Both the suprahyoid and infrahyoid muscles assist in depression of the mandible.

Answer 42

True

Question 43

The ___________ elevate the hyoid, especially during swallowing.

Answer 43

suprahyoid

Question 44

_____________ muscles depress the hyoid and larynx, especially after swallowing.

Answer 44

Infrahyoid

Question 45

What are the four infrahyoid muscles and their innervation?

Answer 45

1. Omohyoid - ansa cervicalis 2. Sternohyoid - a.c. 3. Sternothyroid - a.c. 4. Thyrohyoid - C1 via XII

Question 46

Which infrahyoid muscle is not innervated by the ansa cervicalis?

Answer 46

Thyrohyoid

Question 47

T/F: If the hypoglossal nerve is injured, the tongue will deviate towards the side of the injury.

Answer 47

True

Question 48

What are the four extrinsic muscles of the tongue?

Answer 48

Genioglossus - protrusion Hyoglossus - depression Styloglossus - elevation, retrusion Palatoglossus - elevation

Question 49

Which is the only tongue muscle not innervated by CN XII?

Answer 49

Palatoglossus - CN X (pharyngeal plexus)

Question 50

Which ligament prevents posterior and inferior displacement of the condyles and provides direct support to the TMJ capsule?

Answer 50

Temporomandibular (lateral) ligament