Dental Anatomy: Chapter 17 Exam - Premolars

All Posterior Teeth have at least how many Cusps?

2 Cusps

The Occlusal Surface of Permanent Posteriors creates an inner what, bordered by the marginal ridges?

Occlusal Table

What is a Triangular Ridge?

Cusp Ridges that descend from the cusp tips towards the central part of the Occlusal Table

What is a Transverse Ridge?

A collective term given to the joining of two Triangular Ridges crossing the Occlusal Table transversely, moving from the labial to the lingual outline.

What else is found of the Occlusal Table?

Developmental Grooves

What is the most prominent Developmental Groove on Posterior Teeth?

The Central Groove

What do Marginal Grooves serve as?

A Spillway for food to escape during Mastication

What do Triangular Grooves do?

Separate a Marginal Ridge from the Triangular Ridge of a cusp and at their terminations form the Triangular Fossae

What do Supplemental Grooves appear as?

Shallow, more Irregular Linear Depressions

Where do Supplemental Grooves branch from?

The Developmental Grooves, but these grooves are not always present in the same pattern on the occlusal table of each different tooth type.

Where are Occlusal Pits located?

In the deepest parts of some of these fossae.

Each Developmental Pit is a sharp pinpoint depression where what occurs?

Where two or more grooves meet

For posterior premolars, where is the Height of Contour for the crowns BUCCAL surface?

In the Cervical Third

For posterior premolars, where is the Height of Contour for the crowns LINGUAL surface?

In the Middle Third

The CEJ curvature on each proximal surface is what?

Less pronounced not he posteriors than on anteriors. In fact, the CEJ is often quite straight for posteriors.

Multirooted premolars and molars originate as a single root on the base of the crown called what?

The Root Trunk

What is it called when a tooth has two roots?

Bifurcated

What is it called when a tooth has three roots?

Trifurcated

An area between two or more of these root branches before they divide from the root trunk is called what?

A Furcation

What are the spaces between the roots called?

Furcation Crotches

Each dental arch has how many premolars?

4 Premolars, 2 in each Quadrant

How many types of Premolars are there?

2- First Premolar, and Second Premolar

Where are the types of Premolars located?

The First Premolar is closer to the Midline, and the Second Premolar is next to the First Premolar

Why are Permanent Premolars Succedaneous?

Because the First and Second Premolars replace the Primary First and Second Molars

What is the Premolars MAIN function?

The assist the molars in Grinding Food during mastication.

What do Premolars ALSO function as?

Assistance to the Canines in Piercing and Tearing food with their cusps.A

An older term for a Premolar was?

Bicuspid

As posterior teeth, Premolars have a shorter what than anterior teeth?

Shorter Crown

The Buccal Surface is rounded and has a prominent centrally located vertical what?

Buccal Ridge

Most Premolars usually have ONE root, except for the Permanent Maxillary First Premolarm, which has how many?

TWO

Whether ONE or TWO roots are present, they all have what?

Proximal Root Concavities

Both types of Maxillary Premolars WHAT each other more than Mandibular Premolars do?

RESEMBLE each other more

A what is smaller than a Mandibular Second Premolar

A Mandibular First Premolar

The crown of a Maxillary First Premolar is what than a Maxillary Canine?

Smaller Occlusally

Both Maxillary Premolars have how many cusps of almost equal size?

TWO Cusps

The roots of Maxillary Premolars may penetrate the anterior part of the maxillary sinus as a result of what?

Accidental Trauma, or during tooth extraction because of close relation to these roots to the sinus walls.

When do Maxillary First Premolars erupt?

Between 10 and 11 years of age

What tooth numbers are Maxillary First Premolars?

#5 and #12

What shape is the crown of a Maxillary First Premolar?

An Angular Shape, with Sharp Outlines

The Buccal Cusp is typically about how much higher than the Lingual Cusp?

1 mm

Most Maxillary First Premolars a

What is an Apical Third?

Where a Buccal Root and Lingual Root meet

Other Premolars (Besides the Maxillary First’s) have how many roots?

ONE (Single Rooted)

The Crown of a Maxillary First Premolar is the what of all the Premolars?

The WIDEST MD

The Lingual Surface of a Maxillary First Premolar is what in all directions, but smaller than the Buccal Surface?

Is ROUNDED

The SHORTER Lingual Cusp is sharp, but not as sharp as the what?

As the Buccal Cusp, and is offset toward the mesial

The concavity on the root of a Maxillary First Premolar is possibly at risk for Periodontal Disease because?

It allows and INCREASED DEPOSIT LEVEL

What does Surgical Access by Flap Procedure do?

facilities Periodontal Debridement of root surface of medial root concavity of a Maxillary First Premolar

The Distal Surface of a Maxillary First Premolar is similar to the Mesial, but does not have a what?

A Depression, and more Occlusal Surface shows because the Distal Marginal Ridge is more cervically located than is the Mesial Marginal Ridge