Oral Anatomy Quiz 2

Maintaining vertical dimensions of face, mastication, commissure, shear/cut food

What are the functions of the premolars?

Vertical height at rest (VDR) minus vertical height at occlusion (VDO)

How do you calculate the freeway space (FWS)?

2 (buccal and lingual)

How many cusps do premolars normally have?

Mandibular second premolars

Which premolars are known to sometimes have 3 cusps (one buccal and two lingual)?

4

How many lobes do 2-cusp premolars have?

5

How many lobes do 3-cusp premolars have?

Cervical

Similar to anterior teeth, premolar crowns taper to __________.

Shorter

Compared to anterior teeth, premolars have crowns that are shorter or longer?

Mesial marginal ridge of mandibular first premolar

Compared to anterior teeth, premolars have marginal ridges more horizontal except for...

Cervical third

What is the facial height of contour for all premolars?

Middle third

Where is the lingual height of contour for all premolars?

Buccal

What is the functional cusp of mandibular premolars?

Lingual

What is the functional cusp of maxillary premolars?

Pentagon

From the buccal view, what is the shape outline of crowns on premolars?

Maxillary first premolar

From the buccal view, which premolars have a longer mesial cusp ridge than distal?

Shorter

Besides maxillary first premolars, the mesial cusp ridge is __________ than the distal from the buccal view.

Cervical

From the buccal view, most premolar contact areas are convex and the distal contact is more ____________.

Mandibular first premolar

Which premolar has a distal contact not more cervical than mesial?

Lingual

Most premolar crown outlines narrow toward __________ so some proximal surfaces are visible.

Three cusp mandibular second premolars

Which premolars do not have a crown that tapers toward the lingual?

Buccal

All premolars have a longer buccal or lingual cusp?

Mesial

On most premolars, lingual cusp is mesial or distal to the mid root axis?

Mandibular first premolars

Which premolars have lingual cusp tips distal to the midroot axis?

Mesial

Do most premolars have mesial or distal marginal ridges that are more occlusal?

Mandibular first premolar

Which premolar has a distal marginal ridge that is more occlusal than the mesial?

Faciolingually

Are all premolars wider faciolingually or mesiodistally?

Marginal and cusp ridges

What is the occlusal table of premolars bound by?

Buccal

Are proximal contacts of premolars located more buccal or lingual to the buccolingual midline?

Lingual

Are buccal or lingual embrasures larger on premolars?

Between the maxillary canine and lateral incisor

Where is the largest incisal embrasure located in the mouth?

Transverse ridges

In most premolars, triangular ridges join to form what?

Facial embrasure between the mandibular second premolar and mandibular first molar

In an ideal intercuspal position, the facial cusp tip of the permanent maxillary second premolar opposes the...

Three cusp mandibular second premolars

Which premolars do not have triangular ridges that connect to form transverse ridges?

Central groove

In most premolars, what describes the groove that extends from the mesial fossa to distal fossa?

Mandibular first premolars

Which premolars are most likely to not have a central groove?

Transverse ridges

Mandibular first premolars might not have central grooves because of how prominent what ridges are?

Mandibular

Do mandibular or maxillary premolars have a more noticeable lingual crown tilt?

Lingual

The central groove of mandibular premolars is where in relation to the mid root axis?

Centered

The central groove of maxillary premolars is where in relation to the mid root axis?

Maxillary

Do mandibular or maxillary premolars have a sharper buccal ridge?

Mandibular

Do mandibular or maxillary premolars have buccolingual/faciolingual dimensions closer to square?

Rectangular

Maxillary premolars are shaped how buccolingual/faciolingual?

First

Is the maxillary first or second premolar larger?

First

Does the maxillary first or second premolar have more convergence from the proximal contact to cervical?

Junction of occlusal and middle third

Where is the mesial contact for maxillary premolars?

Middle third

Where is the distal contact for maxillary premolars?

Mesial

In maxillary second premolars, is the mesial or distal cusp ridge shorter?

Mesial

In maxillary second premolars, is the buccal tip located more mesial or distal to the midroot axis?

Mesial

In maxillary first premolars, is the mesial or distal cusp ridge longer?

Distal

In maxillary first premolars, is the buccal cusp tip distal or mesial to the mid root axis?

First

Is the buccal cusp sharper on maxillary first or second premolars?

First

The buccal ridge is more prominant on maxillary first or second premolars?

Mesial

Is the PKT notch located more mesial or distal on maxillary first premolars?

Distal

Is the PKT notch located more mesial or distal on maxillary second premolars?

To allow food to escape during mastication

What is the function of the PKT notch on maxillary premolars?

Maxillary first premolar

Which premolar is most likely to have two roots?

Buccal

Does the buccal or lingual root of a maxillary first premolar point more distal?

Lingual

On maxillary first premolars, is the lingual or buccal root shorter?

Lingual

On the maxillary premolars, the lingual or buccal cusp is shorter?

Second

Do maxillary first or second premolars have buccal and lingual cusps almost the same length?

Second

Does the maxillary first or second premolar have a sharper lingual cusp?

Mesial

Is the lingual cusp of both maxillary premolars located mesial or distal to the midroot axis?

Distal

On maxillary premolars, is the distal or mesial marginal ridge located more cervically?

Second

Is the root crown ratio greater for maxillary first or second premolars?

Second premolar

Which tooth has the largest root crown ratio in the maxillary arch?

Trapezoid

From the proximal view, what shape outline do maxillary premolars have?

Maxillary first premolar

What is the only premolar to have a crown depression?

Mesial

Maxillary first premolars have a crown depression on the mesial or distal?

Same

The distance between the buccal/lingual cusp tips for both maxillary premolars is what?

First

On first or second maxillary premolar would you find a marginal groove?

Mesial (extends into crown depression)

First maxillary premolars have a marginal groove located mesial or distal?

Mesially

Do premolars have more CEJ curvature mesially or distally?

Maxillary first premolar (crown depression joins with root depression)

Which premolar has a mesial root depression more pronounced than its distal root depression?

Second

Do maxillary first or second premolar have a more defined distal root depression?

First

Is the central groove longer on maxillary first or second premolars?

Second

Does the maxillary first or second premolars have more supplemental grooves?

Junction of buccal/middle thirds

For maxillary premolars, where are the distal and mesial contacts located?

First

Is the mandibular first or second premolar longer?

First

Is the buccal cusp apex sharper on mandibular first or second premolars?

Mesial

Is the PKT notch located mesial or distal on the mandibular first premolar?

Distal

Is the PKT notch located mesial or distal on the mandibular second premolar?

Mesial (where PKT notch is)

Is the buccal developmental groove located mesial or distal on mandibular first premolars?

Distal (where PKT notch is)

Is the buccal developmental groove located mesial or distal on mandibular second premolars?

First

Is the buccal developmental groove deeper on mandibular first or second premolars?

Mandibular (ON EXAM)

Are mandibular or maxillary premolars more likely to have PKT notches?

Mesial

On mandibular premolars, are mesial or distal cusp ridges shorter?

First (curve decreases on teeth as they get more posterior in mouth)

Is the facial CEJ more curved on mandibular first or second premolars?

Mandibular first premolar

What is the only tooth in the mouth that has a mesial contact more cervical than the distal?

Occlusal third

Where is the distal contact located for the first mandibular premolar?

Junction of occlusal and middle third

Where is the mesial contact located for the first mandibular premolar?

Second

Is the root crown ratio larger for mandibular first or second premolars?

Distal

Both mandibular premolar roots taper to apex with a mesial or distal bend of apex being more common?

Lingual

Most mandibular premolars taper narrower toward lingual or buccal?

Three cusp mandibular second premolar

Which premolar might have a wider lingual half than buccal half?

Three cusp mandibular second premolars (because its contacts are in the middle third buccolingually)

Which premolar has equally sized buccal and lingual embrasures?

Mesial, distal, or central

Where could the lingual cusp of the mandibular first premolar be located in relation to the mid root axis?

Mesial (if 3-cusp, larger cusp points mesial)

Where is the lingual cusp of mandibular second premolar located mesial, central, or distal to the mid root axis?

First (second premolar cusps are roughly same height)

Is there a larger difference in height between buccal and lingual cusps on mandibular first or second premolars?

Mesiolingual

In a three cusp mandibular second premolars, is the mesiolingual or distolingual cusp typically wider and longer?

Mandibular first premolar

What premolar has a mesial marginal ridge more cervical than the distal marginal ridge?