Development/Eruption

Question 1

When do primary maxillary central incisors erupt? When are they shed?

Answer 1

Erupt 8-12 months Shed 6-7 yrs

Question 2

When do primary maxillary lateral incisors erupt? When are they shed?

Answer 2

Erupt 9-13 months Shed 7-8 yrs

Question 3

When do primary maxillary canines erupt? When are they shed?

Answer 3

Erupt 16-22 months Shed 10-12 yrs

Question 4

When do primary maxillary first molars erupt? When are they shed?

Answer 4

Erupt 13-19 months Shed 9-11 yrs

Question 5

When do primary maxillary second molars erupt? When are they shed?

Answer 5

Erupt 25-33 months Shed 10-12 yrs

Question 6

When do primary mandibular central incisors erupt? When are they shed?

Answer 6

Erupt 6-10 months Shed 6-7 yrs

Question 7

When do primary mandibular lateral incisors erupt? When are they shed?

Answer 7

Erupt 10-16 months Shed 7-8 yrs

Question 8

When do primary mandibular canines erupt? When are they shed?

Answer 8

Erupt 17-23 months Shed 9-12 yrs

Question 9

When do primary mandibular first molars erupt? When are they shed?

Answer 9

Erupt 14-18 months Shed 9-11 yrs

Question 10

When do primary mandibular second molars erupt? When are they shed?

Answer 10

Erupt 23-31 months Shed 10-12 yrs

Question 11

What are succedaneous teeth?

Answer 11

Permanent teeth that replace exfoliated deciduous teeth

Question 12

Describe how the root of anterior and posterior teeth are divided into thirds

Answer 12

Apical third (root tip) Middle third Cervical third

Question 13

Describe how the crown of anterior and posterior teeth are divided into thirds

Answer 13

-incisal/occlusal, middle, cervical -mesial, middle, distal -labial/buccal, middle, lingual

Question 14

Name the 6 line angles found in anterior teeth

Answer 14

1. Mesiolabial
2. Distolabial
3. Mesiolingual
4. Distolingual
5. Labioincisal
6. Linguoincisal

Question 15

Name the 8 line angles found in posterior teeth

Answer 15

1. Mesiobuccal
2. Distobuccal
3. Mesiolingual
4. Distolingual
5. Mesio-occlusal
6. Disto-occlusal
7. Bucco-occlusal
8. Linguo-occlusal

Question 16

Name the 4 point angles found in anterior teeth

Answer 16

1. Mesiolabioinscisal
2. Distolabioincisal
3. Mesiolinguoincisal
4. Distolinguoincisal

Question 17

Name the 4 point angles found in posterior teeth

Answer 17

1. Mesiobucco-occlusal
2. Distobucco-occlusal
3. Mesiolinguo-occlusal
4. Distobucco-occlusal

Question 18

What are mamelons and in which teeth are they found?

Answer 18

• Small bumps on the incisal ridge of maxillary and mandibular central and lateral incisors (permanent only)
• Ridge wears into an edge over time, so mamelons are more common in children than adults

Question 19

Name the depression outlined by the colored lines, and name the protrusion circled in green

Answer 19

Lingual fossa and cingulum

Question 20

What are 4 ways that maxillary lateral incisors exhibit variation?

Answer 20

1. Peg shaped laterals sometimes seen
2. May be missing
3. May have a palato-radicular groove-see
4. May see a large pointed tubercle

Question 21

What is perikymata?

Answer 21

parallel ridges formed by cyclic deposition of enamel

Question 22

What 3 characteristics can chronolgy play a role in?

Answer 22

form, color, and arrangements

Question 23

what 3 teeth are anomolies most often seen in?

Answer 23

maxillary laterals, third molars, and mandibular 2nd premolars

Question 24

when does enamel hypoplasia develop?

Answer 24

during enamel formation

Question 25

Name the amount of time it takes for primary crown formation to continue after birth for the centrals, laterals, canines, 1st molars, and 2nd molars

Answer 25

centrals - 3 months laterals - 4 months canines - 8.5 months 1st molars - 7 months 2nd molars - 10.5 months

Question 26

Is the cementum of permanent teeth thicker or thinner than that of primary teeth?

Answer 26

thicker in permanent teeth

Question 27

When does root formation occur in relation to crown formation?

Answer 27

root formation occurs after crown formation

Question 28

What is a function of continued root formation in relation to eruption?

Answer 28

continued root formation aids in the tooth erupting and contacting opposites

Question 29

what happens to the roots of primary teeth in the absense of a permanent successor?

Answer 29

the root may only partially resorb, possibly resultng in prolonged retention of the primary tooth

Question 30

what happens to alveolar bone height during development in relation to formation of teeth?

Answer 30

the alveolar bone height will increase to accomodate the increasing length of the teeth

Question 31

Name the sequence of eruption of the primary teeth

Answer 31

1) central incisor 2) lateral incisor 3) 1st molar 4) canine 5) 2nd molar

Question 32

around what age is the emergence of primary dentition usually completed?

Answer 32

around 30 months

Question 33

what event marks the beginning of mixed dentition? what event marks the end?

Answer 33

the emergence of the mandibular 1st permanent molar marks the beginning of mixed dentition, and the loss of the last primary tooth marks the end (around 11-12 years of age)

Question 34

T or F: permanent teeth do not begin eruptive movement until the crown is completed

Answer 34

true

Question 35

considering 1st molars are not succedaneous teeth (they do not have primary teeth as predecessors), how is their eruption guided?

Answer 35

by the distal surface of the primary 2nd molars

Question 36

T or F: the premature loss of primary teeth due to caries does not effect the development of permanent dentition

Answer 36

false

Question 37

T or F: the premature loss of primary teeth leads to a lack of space for permanent teeth

Answer 37

true

Question 38

T or F: premature loss of primary teeth may lead to occlusion, loss of arch length, and crowding

Answer 38

true

Question 39

what are developmental lobes?

Answer 39

centers of formation of permanent teeth; there are 4 lobes in each tooth

Question 40

T or F: follicles of developing incisors and canines are labial to deciduous roots

Answer 40

false they are lingual to deciduous roots

Question 41

in relation to primary molars, where are follicles of permanent premolars located?

Answer 41

in the bifurcation of deciduous roots

Question 42

what do permanent incisors, canines, and premolars have in common?

Answer 42

they are all succedaneous teeth; they take place of their primary predeccessors

Question 43

in general, do teeth in the mandibular arch emerge before or after those of the maxilla?

Answer 43

before

Question 44

T or F: size of teeth are not genetically or racially determined

Answer 44

false

Question 45

what does pulp get smaller with age?

Answer 45

due to deposition of secondary dentin

Question 46

4 types of cementoenamel junction

Answer 46

1) enamel overlaps cementum 2) end to end 3) gap exposing dentin 4) cementum overlaps enamel

Question 47

T or F: while teeth are forming, very little environmental influences will affect teeth

Answer 47

true, BUT: tetracycline can cause brown-bluish color, and fluoride can either make enamel less susceptible to caries or cause fluorosis (excess fluoride)

Question 48

T or F: mandibular incisors have the smallest mesiodistal dimensions of all teeth

Answer 48

true

Question 49

in what direction is masticatory stress in the mandibular central?

Answer 49

labio-lingual direction

Question 50

T or F: mandibular central incisor root is wide mesiodistal and narrow labiolingual

Answer 50

false the root is narrow mesiodistal and wide labiolingual

Question 51

is the length of the mandibular central incisor root longer than the maxillary central incisor?

Answer 51

it is as long, and sometimes longer than the maxillary central incisor

Question 52

T or F: in the mandibular central incisor, the mesial cervical line curvature is almost 1/2 the length of the crown

Answer 52

false curvature is almost 1/3 the length of the crown

Question 53

what is an important identification mark to separate the mandibular central and lateral incisors?

Answer 53

the mandibular central incisor's incisal edge is almost at right angles with labiolingual bisecting line

Question 54

T or F: in the mandibular central incisor, the labiolingual dimension is always greater than the mesiodistal dimension

Answer 54

true

Question 55

T or F: in mandibular central incisor roots, two canals may be present

Answer 55

true the root section is often ribbon-like, and sometimes two canals may be present

Question 56

relative to the mandibular central incisor, is the mandibular lateral incisor root longer or shorter?

Answer 56

longer

Question 57

in the mandibular lateral incisor, why does the crown appear to be twisted from an incisal view?

Answer 57

the incisal edge is curved to follow the curvature of the arch

Question 58

at what age is the peak attack of caries most common?

Answer 58

around age 13 when there are only about 5% of primary teeth left

Question 59

after primary teeth are completely finished, about how long is it before tooth resorption begins?

Answer 59

1-2 years

Question 60

T or F: primary teeth are usually more yellow than permanent teeth

Answer 60

false primary teeth are less pigmented than permanent teeth, giving them a whiter appearance

Question 61

describe characteristics of roots of primary molars

Answer 61

they are longer and flare more so that permanent premolars can develop between them

Question 62

compare enamel, dentin, and pulp of primary teeth to permanent teeth

Answer 62

enamel in primary teeth is thin with a consistent depth dentin in thin pulp horns are high and chamber is large

Question 63

compare the mesiodistal vs cervicoincisal measurements in maxillary central incisors of primary and permanent dentition

Answer 63

primary dentition: mesioincisal length is longer than cervicoincisal length permanent dentition: mesioincisal length is shorter than cervicoincisal length

Question 64

T or F: cervical ridges are more pronounced in permanent maxillary central incisors than in primary maxillary central incisors

Answer 64

false cervical ridges are more pronounced in primary maxillary central incisors

Question 65

T or F: the primary maxillary lateral incisor's mesiodistal length is shorter than its cervicoincisal length

Answer 65

true

Question 66

which primary tooth has an appearance of a tooth on steroids?

Answer 66

maxillary canine

Question 67

what is the purpose of the primary mandibular central incisor labiolingual measurement being only 1mm smaller than that of the primary maxillary central incisor?

Answer 67

for strength