**Tooth Morphology/Anatomy

Question 1

Define morphology

Answer 1

the branch of biology that deals with the form and structure of organisms

Question 2

Define dentition

Answer 2

the makeup of a set of teeth; their type, number, and position

Question 3

Define periodontium

Answer 3

the structures that surround and support the teeth

Question 4

Is the alveolar process considered part of the dentition or the periodontium?

Answer 4

periodontium

Question 5

What does PDL stand for?

Answer 5

periodontal ligament

Question 6

Define deciduous dentition

Answer 6

the primary dentition (“baby teeth”)

Question 7

Define succedaneous dentition

Answer 7

the permanent dentition

Question 8

Define nonsuccedaneous dentition

Answer 8

Permanent teeth that are not preceded by a primary tooth

This includes molars

Question 9

What permanent teeth are considered “non-succedaneous”

Answer 9

molars

Question 10

What is the term for the the type of dentition where both permanent and primary teeth are present?

Answer 10

mixed dentition

Question 11

How many sextants are in the adult dentition?

Answer 11

six

They are: maxillary right posterior, maxillary left posterior, maxillary anterior, mandibular right posterior, mandibular left posterior, and mandibular anterior

Question 12

What is the socket within the jawbone in which the root(s) of a tooth are set?

Answer 12

alveolus or lamina dura

Question 13

What is the highest point of alveolar bone between the adjacent teeth?

Answer 13

the alveloar crest

Question 14

Does the periodontal ligament allow for slight movement of the tooth?

Answer 14

Yes

The periodontal ligament serves as a cusion between the tooth and the bone when pressure is exerted or when biting, and therefore must allow for some movement.

Question 15

What is the fibrous connective tissue that makes up the space between the cementum and the alveolus?

Answer 15

periodontal ligament (PDL)

Question 16

Which of the following describes how healthy attached gingiva appears:
a) thick, stippled
b) smooth, red, shiny
c) enlarged, red, swollen
d) flat, pointed between the teeth

Answer 16

a) thick, stippled

Unhealthy attached gingiva will appear smooth, red, and shiny

Question 17

Which of the following describes how healthy free gingiva appears:
a) thick, stippled
b) smooth, red, shiny
c) enlarged, red, swollen
d) flat, pointed between the teeth

Answer 17

d) flat, pointed between the teeth

Unhealthy free gingiva will appear enlarged, red, and swollen

Question 18

Describe the difference between the anatomical crown and the clinical crown?

Answer 18

The anatomical crown is the part of the tooth covered by enamel, and the clinical crown is the part of the tooth that is showing in the oral cavity

Question 19

What would be a potential cause for seeing the clinical root in the oral cavity?

Answer 19

recession or bone loss

The clinical root is the part of the root surface that is showing in the oral cavity

Question 20

Describe the difference between the clinical root and the anatomical root?

Answer 20

The clinical root is the part of the root that is showing in the oral cavity, and the anatomical root is the part of the rooth that is covered in cementum

Question 21

Name the four parts of a tooth

Answer 21

Enamel, dentin, cementum, pulp

Question 22

What is the name of the hard tissue that covers the anatomical crown?

Answer 22

enamel

Question 23

What is the hardest tissue in the human body?

Answer 23

enamel

Question 24

True or False:
Enamel is thinner at the incisal/occlusal area of a tooth, and becomes thicker as it progresses toward the root

Answer 24

False

Enamel is thicker at the incisal/occlusal area of a tooth, and becomes thinner as it progresses toward the root

Question 25

What is the hard tissue that makes up the majority of a tooth?

Answer 25

dentin

Question 26

What part of the tooth provides support for the enamel, and provides insulation to the pulp?

Answer 26

dentin

Question 27

True or False: The bulk of the tooth is the enamel.

Answer 27

False ## Footnote The bulk of the tooth is dentin.

Question 28

What is the second hardest tissue in the human body?

Answer 28

dentin

Question 29

Name the three types of dentin

Answer 29

1) Primary dentin 2) Secondary dentin 3) Tertiary/reparative dentin

Question 30

What type of dentin forms before the tooth erupts? a) primary dentin b) secondary dentin c) tertiary dentin d) reparative dentin

Answer 30

a) primary dentin

Question 31

True or False: Reparative dentin is also known as tertiary dentin.

Answer 31

True

Question 32

True or False: Certain restorative materials can be designed to encourage the formation of reparative dentin

Answer 32

True

Question 33

Name the type of dentin that forms as a result of stimuli like trauma or deep caries

Answer 33

tertiary/reparative dentin

Question 34

What part of the tooth has the highest fluoride content?

Answer 34

Cementum

Question 35

When looking at a moderate depth cavity preparation, what is an identifying way to tell the difference between enamel and dentin tooth structure?

Answer 35

The dentin will be darker in color than the enamel.

Question 36

What is the hard tissue that covers the anatomical root of a tooth?

Answer 36

cementum

Question 37

Name the two types of cementum

Answer 37

1) acellular cementum 2) cellular cementum

Question 38

Which type of cementum forms at the apex of a tooth as in a response to the loss of enamel? a) primary cementum b) acellular cementum c) vital cementum d) cellular cementum

Answer 38

d) cellular cementum

Question 39

What provides the vitality and nutrition to the tooth?

Answer 39

pulp

Question 40

What part of the pulp is located in the coronal portion of the tooth?

Answer 40

Pulp horns and pulp chamber

Question 41

Define convex

Answer 41

a surface that curves outward

Question 42

True or False: An example of a convex anatomical landmark would be a ridge

Answer 42

True

Question 43

Define this anatomical landmark: a major developmental convexity on or near the occlusal surface of a posterior tooth or the the incisal edge of a canine

Answer 43

cusp

Question 44

What is the possible fifth cusp on the lingual surface of the mesiolingual cusp on maxillary first molars?

Answer 44

cusp of Carabelli

Question 45

On what tooth would you find the cusp of Carabelli?

Answer 45

Maxillary first molars ## Footnote The cusp of Carabelli is the possible fifth cusp on the lingual surface of the mesiolingual cusp on maxillary first molars.

Question 46

Define mamelon

Answer 46

a raised area on the incisal edges of newly erupted teeth

Question 47

What is a raised lobe of enamel on the lingual surface found on anterior teeth?

Answer 47

cingulum

Question 48

Name the three major ridges on posterior teeth

Answer 48

1) triangular ridge 2) transverse ridge 3) oblique ridge ## Footnote They are further identified according to their location on the tooth surface and direction in which they transverse the occlusal surface.

Question 49

What is the rounded border of enamel that forms on the mesial and distal boundaries of the occlusal surfaces of posterior teeth and the lingual surfaces of anterior teeth?

Answer 49

marginal ridge

Question 50

Define this anatomical term: ridge

Answer 50

any narrow, linear, elevation on the surface of a tooth

Question 51

Define concave

Answer 51

a surface that curves inward

Question 52

What are the irregular concavities on the surface of a tooth?

Answer 52

fossa

Question 53

Define this anatomical landmark: pit

Answer 53

small pinpoint depressions located at the junction of developmental grooves or at the termination of those grooves

Question 54

What forms as a result of faulty or the incomplete formation of developmental grooves?

Answer 54

a pit

Question 55

What is the name of a groove that is less distinct?

Answer 55

supplemental grooves

Question 56

On posterior teeth, what is the anatomical concavity that separates the cusps of a tooth?

Answer 56

developmental groove

Question 57

Which of the following provides an escape for food from the occlusal surface during the mastication process? a) marginal ridge b) fossa c) spillway d) mamelon

Answer 57

c) spillway

Question 58

Define this anatomical term: fissure

Answer 58

developmental or supplemental grooves with incomplete closure of enamel

Question 59

Where is the most common area to find imbrication lines on a tooth?

Answer 59

the cervical third on the facial of anterior teeth

Question 60

What anatomical feature appears as horizontal, wavelike ripples on anterior teeth?

Answer 60

imbrication lines

Question 61

Define: height of contour

Answer 61

the greatest bulge on the anatomical crown of a tooth

Question 62

True or False: Each tooth has only one height of contour

Answer 62

False

Question 63

What are some reasons that a contact area may be eliminated on a tooth?

Answer 63

tooth movement, loss of adjacent teeth, open contacts in restorations

Question 64

Define: contact areas

Answer 64

the area where approximating teeth in the same arch touch each other

Question 65

Where is the only area of the dentition where two mesial surfaces contact each other?

Answer 65

central incisors

Question 66

Define: embrasure

Answer 66

the spaces adjacent to and surrounding the contact of the teeth in the same arch; named according to the surface of the tooth they approximate

Question 67

How many embrasures surround the proximal contact area?

Answer 67

4

Question 68

What embrasure is made up of interdental papilla?

Answer 68

gingival embrasure

Question 69

What is the term for roots that are divided into two?

Answer 69

bifurcated

Question 70

What is the term for roots that are divided into three?

Answer 70

trifurcated

Question 71

What are the only premolars in the permanent dentition to be bifurcated?

Answer 71

maxillary first premolars

Question 72

Define: furcation

Answer 72

the area of the tooth where the roots divide

Question 73

Define: furrow

Answer 73

a concavity located coronal to the furcation of multi-rooted teeth

Question 74

What is the area called where the crown and the root meet?

Answer 74

cementoenamel junction (CEJ)

Question 75

On multi-rooted teeth, what is the section of the root that extends from the CEJ to the furcation area?

Answer 75

root trunk

Question 76

What tooth has the shortest root in the permanent dentition?

Answer 76

maxillary central incisors

Question 77

Which of the anterior teeth typically have a mesioincisal line angle shaped like a right angle?

Answer 77

maxillary central incisors

Question 78

What is a common area for decay on the lingual surface of permanent maxillary lateral incisors?

Answer 78

lingual pit

Question 79

What are the two most common teeth to be congenitally missing?

Answer 79

third molars and maxillary lateral incisors

Question 80

Define: congenitally missing

Answer 80

a condition present at birth where the teeth are not formed

Question 81

What is the term for a malformation caused by the only two lobes forming a tooth, instead of the normal four?

Answer 81

peg laterals

Question 82

Define: diastema

Answer 82

a space separating anterior teeth

Question 83

What permanent teeth are referred to as the "cornerstones" of the mouth

Answer 83

maxillary canines

Question 84

What teeth have the longest roots in the permanent dentition?

Answer 84

maxillary canines

Question 85

Why does the cervical third of a tooth appear darker than the incisal/occlusal third?

Answer 85

the enamel is thinner at the cervical aspect, and so the darker shade of the dentin is more visible

Question 86

Define: canine eminence

Answer 86

a bulge on the surface of the jawbone where it covers the root of a canine tooth

Question 87

Which tooth is the largest of the permanent maxillary molars?

Answer 87

maxillary first molars

Question 88

Which of the roots on a permanent maxillary first molar is the largest and longest of the three?

Answer 88

palatal root

Question 89

On what tooth would you find a cusp of carabelli?

Answer 89

maxillary first molars

Question 90

Each permanent maxillary first molar has _#__ transverse ridge(s) and __#__ oblique ridge(s)

Answer 90

one transverse ridge and one oblique ridge

Question 91

Would you find an oblique ridge on the permanent maxillary or mandibular molars?

Answer 91

maxillary

Question 92

When looking at the trifurcated roots of the permanent maxillary first and second molars, which have the roots spread further apart?

Answer 92

maxillary first molars

Question 93

What is the smallest tooth in the permanent dentition?

Answer 93

mandibular central incisors

Question 94

Which direction do the roots of teeth typically point?

Answer 94

distally

Question 95

Are the anatomical features of the permanent maxillary or mandibular canines less pronounced?

Answer 95

mandibular canines

Question 96

On the permanent mandibular canine, the anatomical crown is __(shorter or longer)__ and the anatomical root is __(shorter or longer)__ than the maxillary canine?

Answer 96

longer anatomical crown, shorter anatomical root

Question 97

Which cusp on the permanent mandibular first premolars is the largest?

Answer 97

buccal

Question 98

Which is the only premolar on the in the permanent dentition that has a mesiolingual groove?

Answer 98

mandibular first premolars

Question 99

List the three common types of occlusal anatomy on the permanent mandibular second premolars.

Answer 99

H-type Y-type U- or C-type

Question 100

List the names of the buccal cusps on the permanent mandibular first molars.

Answer 100

-mesiobuccal -distobuccal -distal

Question 101

Are the roots bifurcated or trifurcated on permanent mandibular first molars?

Answer 101

bifurcated

Question 102

What is the major difference in the enamel in permanent and primary dentition?

Answer 102

the enamel is much thinner on primary teeth

Question 103

Fill in the blank: The number of cusps on the primary molars is ____ in comparison to the permanent molars.

Answer 103

reversed

Question 104

What is the benefit of primary teeth not having tight contact areas?

Answer 104

it helps to provide a space for the permanent dentition to erupt

Question 105

What is a major anatomical quality of the roots on primary maxillary molars?

Answer 105

the trifucated roots are very spread out

Question 106

How many teeth are in the adult dentition?

Answer 106

32

Question 107

How many teeth are in the primary dentition?

Answer 107

20