DAT 118 Ch. 15 PPT

What does the term ‘dentition’ describe?

describe the natural teeth in the jaws.

How many dentitions does a person have during a lifetime?

primary dentition and permanent dentition.

What are the three dentition periods?

Primary; Mixed; Permanent

What tooth types are included in both arches within the permanent dentition?

8 incisors, 4 canines, 8 premolars, and 12 molar, for a total of 32 teeth

What numbering system designates the primary teeth and permanent teeth?

the Universal Numbering System (UNS)

Why is the Universal Numbering System widely used in the United States?

it is adaptable to electronic data

How are primary teeth designated in the Universal Numbering System?

Primary teeth use letters, A through T, starting with the maxillary right second molar, moving clockwise, and ending with the mandibular right second molar

What is the first dentition present?

The first dentition present is the primary dentition

What tooth types are included in both arches within the primary dentition?

8 incisors, 4 canines, and 8 molars, for a total of 20 teeth

What numbering system is used for the primary dentition?

Universal Numbering System

How are the permanent teeth numbered in the Universal Numbering System?

The permanent teeth- 1 through 32, starting with the maxillary right third molar, moving clockwise and ending with the mandibular right third molar

What number is the permanent maxillary right central incisor?

When speaking about a certain tooth such as the permanent maxillary right central incisor, the clinician calls it “number eight”

What is the permanent dentition?

The permanent dentition is the second dentition to develop

What is the primary dentition period?

The first dentition period

When does the primary dentition period begin?

Begins with the eruption of the primary mandibular central incisors

Between what ages does the primary dentition period occur?

Thus, this period occurs between approximately 6 months and 6 years of age

What teeth are present during the primary dentition period?

Only the primary teeth are present during this tim, with their full eruption completed at 30 months, usually when the primary second molars are in occlusion

What follows the primary dentition period?

Follows the primary dentition period

Between what ages does the mixed dentition period occur?

This period occurs between approximately 6 and 12 years of age

What teeth are present during the mixed dentition period?

Both primary and permanent teeth are present during this transitional stage

What happens during the mixed dentition period?

During this time, both shedding of primary teeth and eruption of permanent teeth begin after their crowns are completed

Why is the mixed dentition period sometimes considered an ugly duckling stage?

The mixed dentition period is sometimes considered an ugly duckling stage because of the different tooth colors, disproportionately sized teeth, and various clinical crown heights

What happens to the patient’s smile during the mixed dentition period?

The patient’s smile shows temporary edentulous areas and crowding

What can happen to the surrounding gingiva during the mixed dentition period?

Additionally, in many cases, the surrounding gingiva responds to all these changes, as well as hormonal fluctuations, by becoming inflamed.

What surrounds and supports each tooth?

Each tooth is surrounded and supported by the bone of the tooth socket, or known as alveolus (plural, alveoli)

Where is each alveolus located?

Each alveolus is located in the alveolar process, or tooth-bearing part of each jaw

What is each alveolar process of the jaws also considered?

Each alveolar process of the jaws is also considered a dental arch—either the maxillary arch or mandibular arch

What are the teeth in the maxilla called?

The teeth in the maxilla are the maxillary teeth

What are the teeth in the mandible called?

The teeth in the mandible are the mandibular teeth

What is occlusion?

Occlusion is the method by which the teeth of the mandibular arch come into contact with those of the maxillary arch

What is the midline of a dental arch?

Each dental arch has a midline, an imaginary vertical plane that divides the arch into two equal halves- a right and left

Which teeth are considered anterior teeth?

The incisors and canines are considered anterior teeth because they are closer to the midline

Which teeth are considered posterior teeth?

In the contrast, the molars (and premolars, if present) are considered posterior teeth because they are farther from the midline

How is each dental arch divided?

Each dental arch can be further divided into two quadrants, with four quadrants in the entire oral cavity

What is the correct sequence of words when describing an individual tooth using a D-A-Q-T System?

The correct sequence of words when describing an individual tooth using a D-A-Q-T System is based on the tooth within its quadrant: D for dentition, A for arch, Q for quadrant, and T for tooth type

What is an example of a D-A-Q-T description?

An example- the written description of the permanent (D) mandibular (A) left (Q) first premolar (T)

What does D represent in the D-A-Q-T System?

Dentition- permanent or primary

What does A represent in the D-A-Q-T System?

Arch- maxillary or mandibulae

What does Q represent in the D-A-Q-T System?

Quadrant- right or left

What does T represent in the D-A-Q-T System?

Tooth- central incisor, lateral incisor, canine, first premolar, second premolar, first molar, second molar, or third molar

What are examples of tooth descriptions using the D-A-Q-T System?

Example: permanent maxillary right canine (6) or primary mandibular left dental (O)

What are sextants?

Some dental treatment plans also include the use of sextants, which further divide each dental arch into three parts according to the relationship to the midline: right posterior sectant, anterior sextant, and left posterior sextant

What does each tooth consist of?

Each tooth consists of a crown and one or more roots

What covers the dentin of the crown?

The crown has dentin covered by enamel

What covers the dentin of the root?

Each root has dentin covered by cementum

What does the inner part of the dentin of both crown and root cover?

The inner part of the dentin of both crown and root also covers the pulp cavity of the tooth

What structures does the pulp cavity have?

The pulp cavity has a pulp chamber, pulp canal (or canals) with an apical foramen (or foramina), and possibly a pulp horn (or horns)

What is the anatomic crown?

The anatomic crown is the part covered by enamel

How does the anatomic crown change throughout the life of the tooth?

It remains mostly constant throughout the life of the tooth, except for attrition and other physical wear

What is the clinical crown?

The clinical crown is that part of the anatomic crown that is visible and not covered by the gingiva

What determines the height of the clinical crown?

Its height is determined by the location of the marginal gingiva

How can the clinical crown change over time?

The clinical crown of a tooth can change over time, especially with gingival recession as the marginal gingiva recedes toward the root

What is the anatomic root?

Similarly, the anatomic root is that part of the root covered by cementum

What is the clinical root?

The clinical root of a tooth is that part of the anatomic root that is visible, subject to variability over time, again related to gingival recession

What are the five surfaces of each tooth?

Each tooth has five surfaces: facial, lingual, masticatory, mesial, and distal surfaces

How are some tooth surfaces identified?

Some of the surfaces of the tooth are identified by the orientational relationship to other orofacial structures, similar to the designation of the soft tissue of the oral cavity

What is the facial tooth surface?

The tooth surface closest to the surface of the face is termed facial

What is the labial tooth surface?

The facial tooth surface closest to the lips is termed labial

What are buccal tooth surfaces?

Those facial tooth surfaces closest to the inner cheek are termed buccal

What is the lingual tooth surface?

The tooth surface closest to the tongue is termed lingual

What are palatal surfaces?

Those lingual surfaces closest to the palate on the maxillary arch are sometimes also termed palatal

What is the masticatory surface?

The masticatory surface is the chewing surface on the most superior surface of the crown

What is the masticatory surface called for anterior teeth?

This is the incisal surface for anterior teeth

What is the masticatory surface called for posterior teeth?

This is the occlusal surface for posterior teeth

Which teeth have at least one major elevation, the cusp?

The masticatory surfaces of both canines and posterior teeth also have at least one major elevation, the cusp; cusps contribute to a significant part of the tooth’s surface

What is the mesial surface?

The surface closest to the midline is considered the mesial

What is the distal surface?

The surface farthest away from the midline is considered the distal

What are the mesial and distal surfaces between adjacent teeth called?

Together, both the mesial and the distal surfaces between adjacent teeth are considered the proximal

What is the interproximal space?

The area between adjacent tooth surfaces is the interproximal space

What is the contact area?

The area where the crowns of adjacent teeth in the same arch physically touch on each proximal surface is the contact area,or, as referred to by clinicians, the contact

What is a line angle?

line angle is formed by the lines created at the junction of two crown surfaces, and the name is derived by combining the names of those two surfaces

What is a point angle?

A point angle is another way to determine a specific area of the crown

How is the name of a point angle determined?

The junction of three surfaces of the crown, the point angle takes its name from those three surfaces

How can a crown surface be divided to designate specific tooth areas?

Finally, a crown surface can be divided both horizontally and vertically into three parts, or thirds, to designate specific tooth area

What defines the front or face of a tooth when the design of a patient’s smile is considered?

The tooth’s angles, height of contour, and spaces define the front or face of a tooth when the design of a patient’s smile is considered, because these features are noted first when contemplating someone’s smile

What happens when the placement and shape of these features are altered?

Altering placement and shape of these features changes the face of a tooth and its perceived size and the appearance of the smile

How should the mesial part of the face and silhouette of a tooth ideally appear compared with the distal part?

Note that ideally the mesial part of the face and silhouette of a tooth is more angled vertically than the distal part of the face of a tooth

Does each tooth type have a specific form?

Each tooth type as already discussed has a specific form, no matter which dentition it is in

What is tooth form related to?

This tooth form is related to the function during mastication for the tooth type, as well as to its role in speech and esthetics

How are the form and function of each tooth type related between primary and permanent dentitions?

The form and function of each tooth type are similar for both the primary and permanent dentitions

What geometric relationship do tooth crowns have?

Tooth types also have tooth forms of the crown that roughly follow specific geometric shapes

How can the crown outline be viewed for each tooth type?

Certain general shapes of the crown outline can be seen for each tooth type when viewing from each of the four perspectives

What is the function of the incisors?

The incisors function as instruments for biting and cutting food during mastication, because of the triangular proximal form of their crowns

What is the function of the canines?

The canines, because of the tapered shape and the prominent cusp of their crowns, function to pierce or tear food during mastication

Where are premolars found?

The premolars, which are found only in the permanent dentition

How do premolars assist the canines?

The premolars, which are found only in the permanent dentition, assist the canines in piercing and tearing food because of prominent cusps of crowns during mastication

How do premolars assist the molars?

The premolars also assist the molars in grinding food during mastication because of the crown’s wide masticatory surface, the occlusal surface

What is the function of the molars?

Finally, as the teeth with the largest and strongest crowns, the molars function in grinding food during mastication, assisted by the premolars

What feature of the molars functions during mastication?

The wide masticatory surface, the occlusal surface of the molars, with the prominent cusps, function during mastication

How is variation of teeth within a particular tooth type viewed by clinicians?

Variation of teeth within a particular tooth type is a given and is always of interest to clinicians

How can individual tooth form and its related function be lost?

The individual tooth form and its related function can be lost as a result of attrition, caries, and trauma or even extraction and shedding with complete loss of the tooth

How can lost functional tooth form be approximated?

Functional tooth form that has been lost can be approximated by restorative treatment, in many cases, using artificial crowns as discussed earlier or replacement bridges, partial or complete and fixed or removable dentures, as well as implants

What are the three dentition periods?

Primary, Mixed, Permanent

How many permanent teeth are there?

32 teeth: 8 incisors, 4 canines, 8 premolars, and 12 molar

How many primary teeth are there?

20 teeth: 8 incisors, 4 canines, and 8 molars

What system is used to designate both primary and permanent teeth?

The Universal Numbering System (UNS)

What letters are used for primary teeth?

A through T, starting with the maxillary right second molar, moving clockwise, and ending with the mandibular right second molar

What numbers are used for permanent teeth?

1 through 32, starting with the maxillary right third molar, moving clockwise and ending with the mandibular right third molar

What are the three main dentition periods by approximate age?

The primary dentition period occurs between approximately 6 months and 6 years of age; the mixed dentition period occurs between approximately 6 and 12 years of age

What is the first dentition period?

The primary dentition period