Form and Function

Question 1

The three major functions of the human teeth are

Teeth display certain ___ which ___ and____ the entire____, and protect the____ and their associated structures from ___ ____

Answer 1

Mastication - chewing

Esthetics - appearance

Phonetics - speech

Teeth display certain forms which align and stabilize the entire dentition, and protect the teeth and their associated structures from potential breakdown.

Question 2

Periodontium

Answer 2

the supporting tissues, both hard and soft, of a tooth.

The periodontium may suffer the consequences of anomalous natural tooth forms or dentist-induced (iatrogenic) imperfections.

Question 3

Comparative Vertebrate Anatomy

The most common _______ type of tooth crown is ____ in shape; it is composed of a _________________.

The conical type of tooth was common in _____ _____ and today is exhibited by many of the ____ ____, including the ________.

Answer 3

The most common primitive type of tooth crown is conical in shape; it is composed of a single cone or lobe.
The conical type of tooth was common in primitive vertebrates and today is exhibited by many of the lower vertebrates, including the reptiles.

Question 4

Comparative Dental Anatomy

These lower vertebrates are called _______ because ________________________.

These animals possess only__________ (_____________) ___ movements because

Answer 4

These lower vertebrates are called homodonts because they have similarly shaped teeth which differ only in size.

These animals possess only up and down (or hinge action) jaw movements because the single conical cusps lock together on closure, not allowing lateral movements.

Question 5

Purpose of conical teeth

Answer 5

The basic purpose of the conical teeth of these animals relates to the grasping of prey and combat. Food is not masticated, but swallowed whole.

Question 6

Mammals

The dental systems of mammals have evolved with much greater diversity. The evolutionary step which made this possible was the development of the ______________________.

From the tritubercular tooth, mammals have evolved _________, so mammals
Mammals exhibit differing tooth forms and are ________in nature.
nMammals are the only animals

Answer 6

The dental systems of mammals have evolved with much greater diversity. The evolutionary step which made this possible was the development of the tritubercular (three-lobed) tooth.

nFrom the tritubercular tooth, mammals have evolved additional lobes, so that most mammalian teeth exhibit four or more lobes.
nMammals exhibit differing tooth forms and are heterodont in nature.
nMammals are the only animals which may display more than a single root per tooth.

Question 7

Dog

Bear

A mammal which is fully ____, but still __________________ (due to its _________ ), is the ____.

This type of hinge movement is common to most other ____________

The bear has a dentition suited to its omnivorous diet. It has ______________________. This allows for __________

Answer 7

A mammal which is fully heterodont, but still lacks lateral jaw movements (due to its interlocking cusps), is the dog.

This type of hinge movement is common to most other carnivores (meat-eaters).

The bear has a dentition suited to its omnivorous diet. It has flattened posterior teeth. This allows for some lateral jaw movements.

Question 8

Primates

The most highly ___ and ____ teeth belong to those animals which are members of the order of mammals known as ____
The crowns of these teeth are normally composed of ____ ____ ____lobes.
This order includes ___________________

Most primates, excluding man, exist in a _____ climate with a basically_______diet of fruits.
The ________ ____ have ____ _____ identical to man.

However, these apes have ____ _____ _____ from an evolutionary past that was ____ and _________________.

Answer 8

The most highly developed and complex teeth belong to those animals which are members of the order of mammals known as primates.
The crowns of these teeth are normally composed of four or more lobes.
This order includes man, apes and monkeys.

Most primates, excluding man, exist in a tropical climate with a basically herbivorous diet of fruits.
The anthropoid apes have dental formulae identical to man. However, these apes have retained elongated canines from an evolutionary past that was carnivorous and do not have the latitude of jaw movement found in man.

Question 9

Man

Man has evolved the most complex dental mechanism of all animals.
Man is _____ and has developed teeth to function in the _______of both meat and plant foods.
In man the ____ _____canines have been ___________ so that they function with the_____________

The individual teeth of man differ both in____ and _____
All teeth in the human dentition are _________________.

Answer 9

Man has evolved the most complex dental mechanism of all animals.
Man is omnivorous and has developed teeth to function in the mastication of both meat and plant foods.
In man the elongated and interlocking canines have been reduced in size so that they function with the rest of the teeth in lateral movements.

The individual teeth of man differ both in size and development.
All teeth in the human dentition are comprised of three or more lobes.

Question 10

Lobes

Animal teeth developed evolutionally from a ____________________thru ____ to _____
A lobe is defined as a ____ ___ ___ __ ____

Lobes are considered only as ______ divisions of a tooth, usually separated by____ _____.
The lobe pattern in the human dentition plays a part in the ___and ____ of each individual tooth.

Answer 10

Animal teeth developed evolutionally from a one-lobed, conical crown, through the tritubercular or three-lobed form, to the four or more lobed crowns found in the primates.
A lobe is defined as a primary division of the tooth.

Lobes are considered only as anatomical divisions of a tooth, usually separated by primary grooves.
The lobe pattern in the human dentition plays a part in the form and function of each individual tooth.

Question 11

Lobes - Anterior Teeth

Anterior teeth are composed of _____ lobes.

The ____ labial lobes are named the ________________
The remaining lobe is named the _________ and _________ the________

Evidence for the presence of the ____ labial lobes is sometimes found on the ____ edge of___ ____ ____in the form of ____(slightly ____ incisal ______ of of the ____ lobes).
When the incisors are in functional occlusion, the mamelons are abraded away soon after eruption.

Answer 11

Anterior teeth are composed of four lobes.

The three labial lobes are named the mesiolabial, middle labial and distolabial lobes.
The remaining lobe is named the lingual lobe and encompasses the cingulum.

Evidence for the presence of the three labial lobes is sometimes found on the incisal edge of newly erupted incisors in the form of mamelons (slightly rounded incisal terminations of of the labial lobes).
When the incisors are in functional occlusion, the mamelons are abraded away soon after eruption.

Question 12

Lobes

Anterior

Further evidence of separation of the labial lobes of____ _____ teeth is found in the form of____ _____ _____found in the ____ portion of the____ surface.
These ___,_______ _______ are named the ______________________

Answer 12

Further evidence of separation of the labial lobes of all anterior teeth is found in the form of two shallow depressions found in the incisal portion of the labial surface.
These linear, vertical depressions are named the mesiolabial and distolabial developmental depressions.

Question 13

Lobes - Premolars

Most premolars exhibit ____ lobes, ___ buccal and ____ lingual. They are named the ________

The exception is a _____________ with ____ lingual cusps. It has ____lobes, ___ buccal and ___ lingual. The lingual lobes are named the _______

Answer 13

Most premolars exhibit four lobes, three buccal and one lingual. They are named the mesiobuccal, middle buccal, distobuccal and lingual lobes.

The exception is a mandibular second premolar with two lingual cusps. It has five lobes, three buccal and two lingual. The lingual lobes are named the mesiolingual and distolingual lobes.

Question 14

Lobes - Molars

Maxillary molars normally have ____ lobes, which are named the ________________
Evidence of lobe separation can be found in the________ ______ _______ ______.

_______________________ are not found.

There is one maxillary molar that exhibits ____________. That is a maxillary ___ or ____ “Heart” shaped molar. This tooth has _buccal lobes and _ lingual lobe.

Answer 14

Maxillary molars normally have four lobes, which are named the mesiobuccal, distobuccal, mesiolingual and distolingual lobes.
Evidence of lobe separation can be found in the central, buccal and lingual grooves. Facial developmental depressions are not found.

There is one maxillary molar that exhibits less than four lobes. That is a maxillary 2nd or 3rd “Heart” shaped molar. This tooth has 2 buccal lobes and 1 lingual lobe.

Question 15

Exception

Answer 15

There is one maxillary molar that exhibits less than four lobes. That is a maxillary 2nd or 3rd “Heart” shaped molar. This tooth has 2 buccal lobes and 1 lingual lobe.

Question 16

Mandibular Molars

\
Mandibular first molars normally have )___cusps and____lobes. They are named like the lobes of the maxillary molars. The lobe for the fifth cusp is named the ____ lobe.

Most other mandibular molars exhibit___ cusps and ___ lobes, with the terminology the same as for the maxillary molars.

Answer 16

Mandibular first molars normally have five cusps and five lobes. They are named like the lobes of the maxillary molars. The lobe for the fifth cusp is named the distal lobe.

Most other mandibular molars exhibit four cusps and four lobes, with the terminology the same as for the maxillary molars.

Question 17

General Occlusal Curvatures and Axial Position

The general arrangement of the_____and the ______ of the individual teeth are arranged in such a way as to allow

(1)

2)

Answer 17

The general arrangement of the arches and the inclination of the individual teeth are arranged in such a way as to allow

(1) the most efficient uses of the forces of mastication and
2) to stabilize and protect the dental arches.

Question 18

Curve of Spee

Curve of Spee - this _________ curvature begins at the______ and follows the

___ ___ ___ of the ___ and ___
The Curve of Spee curves ____ from ____ to _____ and is best viewed from the ____ aspect.

Based on the Curve of Spee, the crowns of molars tilt towards the ____ and the roots towards the ____.
Note - the _____ are the most upright or vertical teeth in the dental arches.

Answer 18

Curve of Spee - this anteroposterior curvature begins at the canines and follows the buccal cusp tips of the premolars and molars.
The Curve of Spee curves upward from anterior to posterior and is best viewed from the facial aspect.

Based on the Curve of Spee, the crowns of molars tilt towards the mesial and the roots towards the distal.
Note - the premolars are the most upright or vertical teeth in the dental arches.

Question 19

Curve of Wilson

The Curve of Wilson is the__________curvature of the _____ plane of the _____teeth.
The purpose of this arc of occlusal curvature is to____ the paths of the _____ during _____ movements and to allow for____movements.

For the occlusal surfaces of posterior teeth to conform to this curve, (1) crowns of _______ posterior teeth incline to the_____ and (2) crowns of ______ posterior teeth incline to the______
This curve is deeper _______and the_____’s inclination is greater than that of the ______.

Because of the Curve of Wilson and its associated tooth inclinations, the ____ cusps of _____ molars and the____ cusps of_____molars appear to be longer.

Answer 19

The Curve of Wilson is the medio-lateral curvature of the occlusal plane of the posterior teeth.
The purpose of this arc of occlusal curvature is to complement the paths of the condyles during mandibular movements and to allow for lateral movements.

For the occlusal surfaces of posterior teeth to conform to this curve, (1) crowns of mandibular posterior teeth incline to the lingual and (2) crowns of maxillary posterior teeth incline to the buccal.
This curve is deeper posteriorly and the molar’s inclination is greater than that of the premolars.

Because of the Curve of Wilson and its associated tooth inclinations, the buccal cusps of mandibular molars and the lingual cusps of maxillary molars appear to be longer.

Question 20

Compensating Occlusal Curvature

Compensating Occlusal Curvature - the ____ ____curvature of the ____ plane, which is the ____ of the curve of ____ and the Curve of____.

Synonym -
This curvature is ____ for the mandibular arch and ____ for the maxillary arch.

Answer 20

Compensating Occlusal Curvature - the three dimensional curvature of the occlusal plane, which is the combination of the curve of Spee and the Curve of Wilson. Synonym - Sphere of Monson
This curvature is concave for the mandibular arch and convex for the maxillary arch.

Question 21

Axial Position

Axial Position - the inclination of a tooth from a ____ axis. This inclination is normally described in ____ and _____ directions.
Axial position is normally described in terms of the ____’s inclination, which means that the __________
These inclinations are necessary for the proper ______________.
There is a wide range of axial positions, as is evident from the following descriptions for individual permanent teeth.

Answer 21

Axial Position - the inclination of a tooth from a vertical axis. This inclination is normally described in mesiodistal and faciolingual directions.
Axial position is normally described in terms of the root’s inclination, which means that the crown is normally inclined in the opposite direction.
These inclinations are necessary for the proper occlusal and incisal function of the teeth.
There is a wide range of axial positions, as is evident from the following descriptions for individual permanent teeth.

Question 22

Maxillary anterior teeth Axial Position

The faciolingual dimension:

The mesiodistal direction:

incisors’

canine

Answer 22

Maxillary anterior teeth

The faciolingual dimension:

the maxillary anterior teeth exhibit great inclination of the root toward the lingual, when considering the faciolingual dimension.

The mesiodistal direction:

the maxillary incisors’ roots incline very slightly toward the mesial and the canine root inclines toward the distal.

Question 23

Maxillary premolars

Root inclinatiosn are ____.

Fl

Mesiodistal

Answer 23

nmaxillary premolars’ root inclinations are slight: toward the lingual in the faciolingual dimension and toward the distal in the mesiodistal dimension.

Question 24

Maxillary molars

FL

MD

Answer 24

the roots of maxillary molars display great lingual inclination and moderate mesial or distal inclination.

Question 25

Mandibular anterior teeth

Answer 25

The mandibular incisors and canines exhibit great lingual root inclination in the faciolingual direction.
Mesiodistally, the incisors are nearly straight or display only minor mesial root inclination, while the canines have slight distal root inclination.

Question 26

Mandibular premolars

Question 27

Mandibular molars

Answer 27

the mandibular molars exhibit moderate to great buccal and distal root angulations.

Question 28

Crown Surface Form - Introduction

The geometric configuration of all the crown surfaces of the teeth, except for the incisal and occlusal, can be placed in one of three general categories:

Answer 28

The geometric configuration of all the crown surfaces of the teeth, except for the incisal and occlusal, can be placed in one of three general categories: (1) triangular, (2) trapezoidal or (3) rhomboidal.

Question 29

Crown Surface Form -
Facial and Lingual Surfaces

From the facial and lingual aspects, the crowns of all permanent teeth can be roughly described as ___ in shape.
The incisal or occlusal side forms the____ of the trapezoid, while the _____ represents the

Arrangement of these trapezoidal shaped crowns side by side in the dental arches creates ___________ between the teeth and________between each pair of adjacent teeth.

Since the shorter parallel side of the trapezoid is at the cervical, there is

Answer 29

From the facial and lingual aspects, the crowns of all permanent teeth can be roughly described as trapezoidal in shape.
The incisal or occlusal side forms the base of the trapezoid, while the cervical represents the shorter parallel side.

Arrangement of these trapezoidal shaped crowns side by side in the dental arches creates interproximal spaces between the teeth and one contact area between each pair of adjacent teeth.

Since the shorter parallel side of the trapezoid is at the cervical, there is plenty of space available for bony support around the root(s) of each tooth.

Question 30

Crown Surface Form -
Mesial and Distal Surfaces

In a proximal view, the crowns of the permanent anterior teeth exhibit a ____ shape.

Note - the base of the triangle is at the ______; the apex of the triangle is at the_____
This shape fits into the prescribed function of the anterior teeth, since the incisal functions as a ____ in ____, ____and _____ food material.

Answer 30

In a proximal view, the crowns of the permanent anterior teeth exhibit a triangular shape. Note - the base of the triangle is at the cervical; the apex of the triangle is at the incisal.
This shape fits into the prescribed function of the anterior teeth, since the incisal functions as a wedge in tearing, biting and incising food material.

Question 31

Crown Surface Form -
Mesial and Distal Surfaces

MaxillaryPosterior

The crowns of the maxillary posterior teeth have proximal surfaces which are roughly ______ in shape.

Note - the base of the trapezoid is at the ____; the buccal and lingual surfaces converge towards the _____.
This shape aids in the _____ ___ ____ during mastication and facilitates the _____________

Answer 31

The crowns of the maxillary posterior teeth have proximal surfaces which are roughly trapezoidal in shape. Note - the base of the trapezoid is at the cervical; the buccal and lingual surfaces converge towards the occlusal.
This shape aids in the distribution of the forces during mastication and facilitates the self-cleansing process of the teeth.

Question 32

Crown Surface Form -
Mesial and Distal Surfaces

Mandibuilar Posterior

From the proximal aspect, the crowns of the mandibular posterior teeth are roughly _______ in shape.
The crowns incline towards the _____
This form and inclination allows for the

Answer 32

From the proximal aspect, the crowns of the mandibular posterior teeth are roughly rhomboidal in shape.
The crowns incline towards the lingual.
This form and inclination allows for the proper interlocking of the mandibular and maxillary teeth during mastication.

Question 33

Contact Areas

The places where adjacent teeth touch are called contact areas. The mesial surface of one tooth normally contacts the distal surface of the adjacent tooth.
Each tooth normally contacts ____ adjacent teeth. The most posterior tooth in each quadrant only has a tooth on the mesial to contact.

The central incisors contact each other at the ____. __________________________.

Contact areas normally ____ in size with____
The initial contact after eruption is more of a “______” in size. With age the contact _____ and is called a _______________.

Answer 33

The places where adjacent teeth touch are called contact areas. The mesial surface of one tooth normally contacts the distal surface of the adjacent tooth.
Each tooth normally contacts two adjacent teeth. The most posterior tooth in each quadrant only has a tooth on the mesial to contact.

The central incisors contact each other at the midline. The adjacent mesial surfaces are in proximal contact.
Contact areas normally increase in size with age.
The initial contact after eruption is more of a “point” in size. With age the contact broadens and is called a contact area.

Question 34

Contact Areas - Continued

The broadening of contact is due to the ____ that occurs when the proximal surfaces of the teeth _______________.
As a result of this abrasive action, the ______ length of the dental arches slowly becomes _____.The teeth become____ _____and move_____ or closer to the midline (____ ____).

The proper location of contact areas aid in _____________
Proper contact areas also prevent __________. Chronic packing of food between the teeth may result in _________of the _____ ____ and lead to a ___________.

Answer 34

The broadening of contact is due to the abrasion that occurs when the proximal surfaces of the teeth rub against each other.
As a result of this abrasive action, the mesiodistal length of the dental arches slowly becomes shorter. The teeth become narrower mesiodistally and move mesially or closer to the midline (mesial drift).
The proper location of contact areas aid in stabilizing the dental arches.
Proper contact areas also prevent food material from packing between the teeth. Chronic packing of food between the teeth may result in inflammation of the supporting structures and lead to a breakdown of the bony component of the periodontium.

Question 35

Contact Areas - Continued

The _________________________ in dental restorations is of extreme importance.
The contact area must be ____ to ______
Its proper location, both in an__________________ direction and a__________ direction, is also important in the________________

Answer 35

The replacement of proper contact in dental restorations is of extreme importance.
The contact area must be tight to prevent food packing.
Its proper location, both in an inciso- (occluso)cervical direction and a facio-lingual direction, is also important in the food flow pattern.

Question 36

General Rules for Contact Areas

Answer 36

1. Contact areas become more cervically located from anterior to posterior in each quadrant.
2. The distal contact area of a tooth normally has a more cervical location than the mesial contact area.
3. The relative size of the contact areas increases from anterior to posterior in each quadrant.
4. Anterior teeth have contact areas which are normally centered in the faciolingual dimension.
5. Posterior teeth have contact areas which are normally located to the buccal of center in the faciolingual dimension

Question 37

Interproximal Space

Interproximal space - the ______shaped area between adjacent teeth that is _______ to the contact area.

The interproximal space is usually filled with ______________________.

This space can be described as a triangle, formed by

(1) ,

(2)

(3) .

The general triangular shape is important to the ______________ and aids in the ______________

Answer 37

Interproximal space - the triangular shaped area between adjacent teeth that is cervical to the contact area.
The interproximal space is usually filled with gingival tissue known as the interdental papilla.

This space can be described as a triangle, formed by (1) alveolar bone at its cervical base, (2) the proximal surfaces of adjacent teeth on its sides and (3) the contact area of the adjacent teeth at its apex.
The general triangular shape is important to the proper stimulation of the periodontium and aids in the self-cleansing process of the dentition.

Question 38

Embrasures

Embrasure -the open ______ between the proximal surfaces of adjacent teeth, where they diverge facially, lingually, incisally (occlusally) or cervically from the contact area.
When viewing the teeth from the facial or lingual aspects, the two embrasures which may be observed are the______________________.
The cervical (gingival) embrasure corresponds to the______ _____ and is normally _____in area than the incisal (occlusal) embrasure.
When viewing the teeth from the incisal or occlusal aspect, the two embrasures which are visible are named ________________________.
If an imaginary line is drawn to bisect any embrasure space, the two portions so prescribed should be approximately equal in- ____and _____,or in other words, they should be symmetrical.
Asymmetrical embrasure form may affect the ____________________.. In the anterior teeth, it may also compromise_______.

Answer 38

Embrasure -the open space between the proximal surfaces of adjacent teeth, where they diverge facially, lingually, incisally (occlusally) or cervically from the contact area.
When viewing the teeth from the facial or lingual aspects, the two embrasures which may be observed are the incisal (occlusal) and cervical embrasures.
The cervical (gingival) embrasure corresponds to the interproximal space and is normally larger in area than the incisal (occlusal) embrasure.
When viewing the teeth from the incisal or occlusal aspect, the two embrasures which are visible are named labial (buccal) and lingual embrasures.
If an imaginary line is drawn to bisect any embrasure space, the two portions so prescribed should be approximately equal in size and shape, or in other words, they should be symmetrical.
Asymmetrical embrasure form may affect the health of the periodontium. In the anterior teeth, it may also compromise esthetics.

Question 39

Embrasures
Proper embrasure form has two main physiological purposes:
(1)
(2)
These purposes complement each other in the _____ and ______ of the_______.

Answer 39

Proper embrasure form has two main physiological purposes:
(1) to serve as a spillway for food material during mastication
(2) to serve as an integral part of the self-cleansing process of the teeth.
These purposes complement each other in the protection and stimulation of the periodontium.

Question 40

Embrasures - General Rules

Answer 40

1. From the facial or lingual aspect, incisal (occlusal) embrasures increase in relative size from the anterior teeth toward the posterior.
2. From the facial or lingual aspect, cervical (gingival) embrasures decrease in relative size from anterior to posterior.
3. From the incisal aspect, the labial and lingual embrasures are nearly equal in size in anterior teeth.
4. From the occlusal aspect, the lingual embrasure is normally larger than the buccal embrasure in posterior teeth.
5. When one side of an embrasure (tooth outline) has a certain contour, the other side of the embrasure will normally have a similar contour.

Question 41

]Contact Areas & Embrasure Form

Answer 41

The contact area becomes more cervically located as you move posteriorly in the arch; the relative size of the incisal (occlusal) embrasure increases and the relative size of the cervical embrasure decreases.
As the contact area moves farther to the buccal in the posterior teeth, the lingual embrasure becomes relatively larger.

Question 42

Facial Line Angles

The ___ facial line angles of the _____ teeth and ______are normally quite ______ when compared to the more______ ______line angles of the same teeth.
Their outline is best seen from the_________aspect because they are seen in cross section.

These prominent line angles are actually the ____ ____of ____ _____
For any specific facial embrasure, the line angles are located ____ _____ to each other in the ____ _____.
This placement is consistent with the concept of ________ in embrasure form.

Answer 42

The two facial line angles of the anterior teeth and premolars are normally quite prominent, when compared to the more rounded lingual line angles of the same teeth.
Their outline is best seen from the incisal (occlusal) aspect because they are seen in cross section.

These prominent line angles are actually the facial termination of the facial embrasures.
For any specific facial embrasure, the line angles are located directly adjacent to each other in the faciolingual dimension.
This placement is consistent with the concept of symmetry in embrasure form.

Question 44

Heights of Contour

The height of contour or ___ __ _____ is the greatest_____ OF CONTOUR _____-______on the ___ and ____ surface and is best observed by viewing these surface outlines from a _____ aspect.
___ and ____lsurfaces also have heights of contour and they are normally located at the ___ ____ and are called ____ ____, ____ ____ ____
As with embrasure form, these contours aid in proper ____and _____ of the ____ tissue.
If the contour is ___, the flow of food material will be ______ ____ ___ ___ _____and _____ stimulation of these tissues may result in their ____.
When_____ contour does not provide adequate ____, the ______ or ____to the gingival tissues may also result in their _____.
Thus, it is very important for the dentist to restore correct facial and lingual heights of contour.

Answer 44

The height of contour or crest of contour is the greatest area of contour inciso(occluso)-cervically on the facial and lingual surface and is best observed by viewing these surface outlines from a proximal aspect.
Mesial and distal surfaces also have heights of contour and they are normally located at the contact areas and are called proximal ridges, mesial contact ridges
As with embrasure form, these contours aid in proper protection and stimulation of the gingival tissue.
If the contour is excessive, the flow of food material will be deflected away from the gingiva and inadequate stimulation of these tissues may result in their breakdown.
When insufficient contour does not provide adequate protection, the overstimulation or insult to the gingival tissues may also result in their deterioration.
Thus, it is very important for the dentist to restore correct facial and lingual heights of contour.

Question 45

Heights of Contour - Continued

The _____ height of contour of all teeth (anteriors and posteriors) is located in the ____ third.

The____ height of contour of all anterior teeth is located in the ____ third.
The____ height of contour of all posterior teeth is located in the ______________.

Answer 45

The facial height of contour of all teeth (anteriors and posteriors) is located in the cervical third.
The lingual height of contour of all anterior teeth is located in the cervical third.
The lingual height of contour of all posterior teeth is located in the middle or occlusal third.

Question 46

Cervical Line Curvatures

The cervical line or cemento-enamel junction is defined as the observable line around the tooth where the ________

The cervical line is a ____ entity, in contrast to the ____ line which may be ever changing.
On any individual tooth the amount (_____) of curvature of the cervical line seems to be related to (1)_______________ and (2) the __________

Answer 46

The cervical line or cemento-enamel junction is defined as the observable line around the tooth where the cementum and enamel meet.
The cervical line is a stable entity, in contrast to the gingival line which may be ever changing.
On any individual tooth the amount (depth) of curvature of the cervical line seems to be related to (1) the width and length of the crown and (2) the location of contact areas proximally.

Question 48

Rules of Cervical Line Contours

Rule #1 - the cervical line is normally curved (convex) toward the ____ on the ___/____surfaces of teeth.
Rule #2 - the cervical line is normally curved (convex) toward the ______ on the ___/______surfaces of teeth.
Rule #3 - the amount (depth) of curvature on any tooth is normally greater on the ____surface than on the ____ surface

Rule #4 - cervical lines on___ ____ _____ of adjacent teeth have approximately the ____ depth of curvature.

Rule #5 - the depth of curvature on all surfaces is____ on the____ ____ and _____ posteriorly.

.

Answer 48

Rule #1 - the cervical line is normally curved (convex) toward the apical on the facial and lingual surfaces of teeth.
Rule #2 - the cervical line is normally curved (convex) toward the incisal (occlusal) on the mesial and distal surfaces of teeth.
Rule #3 - the amount (depth) of curvature on any tooth is normally greater on the mesial surface than on the distal surface

Rule #4 - cervical lines on adjacent proximal surfaces of adjacent teeth have approximately the same depth of curvature.

Rule #5 - the depth of curvature on all surfaces is greatest on the central incisors and decreases posteriorly.

.

Question 49

Gingival Line

The gingival line is the imaginary line which marks the level of termination of the ___ ___surrounding the tooth.

It is also called the _________or ________
The level of the gingival line is____ and is usually ____ the cervical line early in life.
As the individual ages, the gingival line often ____ __ ___ _____ level.
The gingival line separates the ___ crown and root.
The cervical line separates the ____ crown and root.

Answer 49

The gingival line is the imaginary line which marks the level of termination of the soft tissue surrounding the tooth. It is also called the gingival margin or gingival crest.
The level of the gingival line is variable and is usually above the cervical line early in life.
As the individual ages, the gingival line often recedes to a lower level.
The gingival line separates the clinical crown and root.
The cervical line separates the anatomical crown and root.

Question 50

Epithelial Attachment

The epithelial attachment is the attachment of the____ to the____

The epithelial attachment can be distinguished from the periodontal ligament even though both structures are components of the ____ _____apparatus.
The epithelial attachment serves as the connection for the ____ _____tissue and is ____ in comparative area.
The periodontal ligament provides the attachment of the____ ____ and is much ____ ____ in area.

Answer 50

The epithelial attachment is the attachment of the gingiva to the tooth.
The epithelial attachment can be distinguished from the periodontal ligament even though both structures are components of the tooth’s attachment apparatus.
The epithelial attachment serves as the connection for the soft (gingival) tissue and is limited in comparative area.
The periodontal ligament provides the attachment of the hard tissue (bone) and is much more extensive in area.

Question 51

Epithelial Attachment

Since there is usually a ____ between the ___ ____ and the ___ ___, these two entities are not normally located at the ______________.
Like the gingival margin, the epithelial attachment has a tendency to _________________________.
Apical migration of the periodontal ligament often occurs in the presence of____ ____
The epithelial attachment is normally found close to the level of the_____

Answer 51

nSince there is usually a sulcus between the gingival margin and the epithelial attachment, these two entities are not normally located at the same level on the tooth.
nLike the gingival margin, the epithelial attachment has a tendency to migrate apically during a person’s lifetime.

Apical migration of the periodontal ligament often occurs in the presence of periodontal disease.
The epithelial attachment is normally found close to the level of the CEJ.

Question 52

Continuity of Marginal Ridges

Marginal ridges are the mesial and distal terminations of the ____ surfaces of posterior teeth and the ___ surfaces of anterior teeth.
Marginal ridges are normally _____on the_____ teeth.
The height of marginal ridges of adjacent teeth in the same arch should be at the_____________.

Adjacent marginal ridges are normally shaped so that they create a _________________.
The _____ and _____ of the adjacent marginal ridges directly affect the____ ____
Marginal ridges on adjacent teeth should be similar in ____ and ____

Answer 52

Marginal ridges are the mesial and distal terminations of the occlusal surfaces of posterior teeth and the lingual surfaces of anterior teeth.
Marginal ridges are normally bulkier on the posterior teeth.
The height of marginal ridges of adjacent teeth in the same arch should be at the same level.

nAdjacent marginal ridges are normally shaped so that they create a small occlusal embrasure on posterior teeth.
nThe heights and shapes of the adjacent marginal ridges directly affect the embrasure form.
nMarginal ridges on adjacent teeth should be similar in height and shape.

Question 53

Continuity of Central Grooves

The central grooves of ____ ___ are normally aligned into ____, more or less ____ valley.
This allows for a ___ through the centers of the occlusal surfaces of the posterior teeth, which results in more ___ ___ and ____ ____ during mastication.

Answer 53

The central grooves of posterior teeth are normally aligned into one, more or less continuous valley.
This allows for a trough through the centers of the occlusal surfaces of the posterior teeth, which results in more efficient function and food flow during mastication.

Question 54

Faciolingual Taper

Faciolingual taper - a tapering ____ in the ______ width of the teeth, which starts at the ____ ___ ____ surfaces and extends____

Note - this creates the _____ embrasures.
_______ and __________ may exhibit__________________.

Answer 54

Faciolingual taper - a tapering reduction in the mesiodistal width of the teeth, which starts at the center of the proximal surfaces and extends lingually. Note - this creates the lingual embrasures.
Mandibular second premolars and maxillary first molars may exhibit reverse faciolingual taper.

Question 55

Occlusal Anatomy

Another feature of ___ _____ is the___ and ____ pattern on the____ surface, or in other words, the occlusal anatomy.
In any dental restorative procedure, the occlusal anatomy of a tooth should be reproduced to preexisting ______ ______ ___/____

Answer 55

Another feature of posterior teeth is the groove and ridge pattern on the masticating surface, or in other words, the occlusal anatomy.
In any dental restorative procedure, the occlusal anatomy of a tooth should be reproduced to preexisting form, location, and relative height or depth.

Question 56

Root Shape & Number of Branches

The ___, ____ and ____ of root branches are also intimately related to a tooth’s form and function.
The canine, by virtue of its ____ in the arch, and its ____ ____ ___ ____ of ____, has the ___ and ____ root in both arches.
The molars are multirooted to complement the increased size of the _____, as they function in ____.
Root form is directly related to (1)____ ____, (2)___ ___ ___ _____and (3) ____

Answer 56

The shape, length and number of root branches are also intimately related to a tooth’s form and function.
The canine, by virtue of its location in the arch, and its evolutionary function as the fang of carnivores, has the longest and strongest root in both arches.
The molars are multirooted to complement the increased size of the occlusal table, as they function in grinding.
Root form is directly related to (1) crown form, (2) placement in the arch and (3) function.

Question 57

Roots - General Rules

Roots are normally widest towards the _____ ____and taper toward the ____
Anterior teeth and premolars normally have ____ roots. An exception is the____ ___ ___which normally exhibits ___ root branches, a ___ and a ___
Maxillary molars normally possess ___ roots, _____ and _____
Mandibular molars normally have ____ roots, ____ and ____ branch.

Answer 57

Roots are normally widest towards the cervical area and taper toward the apex.
Anterior teeth and premolars normally have single roots. An exception is the maxillary first premolar, which normally exhibits two root branches, a buccal and a lingual.
Maxillary molars normally possess three roots, one lingual and two buccal.
Mandibular molars normally have two roots, one mesial and one distal branch.

Question 58

Conclusions

Answer 58

Tooth form and function are directly related.
The potential for the breakdown of the periodontium is directly related to form and function.
The dentist is under an obligation to understand and apply the principles of form and function in all dental procedures.