Ch. 307 - Development and Developmental Anomalies of the Teeth

Question 1

Primary teeth form in dental crypts by ___ weeks of fetal life

Answer 1

12

Question 2

The permanent 1st, 2nd, and 3rd molars arise from buds that develop at approximately __, ___, and ___

Answer 2

4 mos of gestation, 1 yr of age, 4-5 yr of age

Question 3

Lay down an organic matrix that forms enamel

Answer 3

Ameloblast

Question 4

Calcification of primary teeth begins at ___ and concludes at ___ with mineralization of the 2nd primary molars

Answer 4

3-4 months in utero; postnatally at approximately 12 months

Question 5

Primary dentition: Earliest to calcify

Answer 5

Maxillary central incisor at 3-4 month in utero

Question 6

Primary dentition: Last to calcify

Answer 6

Maxillary second molar at 6 months in utero

Question 7

Permanent dentition: Earliest to erupt

Answer 7

Mandibular central incisor at 6-7 years

Question 8

Permanent dentition: Last to erupt

Answer 8

Third molar at 17-21 years

Question 9

Occurs when no tooth buds form as in ectodermal dysplasia or when there is a disturbance of a normal site of initiation (e.g. area of a palatal cleft)

Answer 9

Anodontia

Question 10

Teeth that are most commonly absent

Answer 10

1) 3rd molars 2) Maxillary lateral incisors 3) Mandibular 2nd premolars

Question 11

Occurs when the dental lamina produces more than the normal number of buds

Answer 11

Supernumerary teeth

Question 12

MC location of supernumerary teeth

Answer 12

Between maxillary central incisors

Question 13

2 teeth joined together

Answer 13

Twinning

Question 14

Twinning is most often observed where

Answer 14

Mandibular incisors of the primary dentition

Question 15

Twinning can result from 3 phenomena

Answer 15

1) Gemination 2) Fusion 3) Concrescence

Question 16

Result of the division of 1 tooth germ to form a bifid crown on a single root with a common pulp canal

Answer 16

Gemination

Question 17

Joining of incompletely developed teeth that, owing to pressure, trauma, or crowding, continue to develop as 1 tooth

Answer 17

Fusion

Question 18

Single wide crown supported on 2 roots

Answer 18

Fusion

Question 19

Attachment of the roots of closely approximated adjacent teeth by an excessive deposit of cementum

Answer 19

Concrescence

Question 20

Type of twinning that is found most often in the maxillary molar region

Answer 20

Concrescence

Question 21

Group of hereditary conditions that manifest in enamel defects of the primary and permanent teeth without evidence of systemic disorder

Answer 21

Amelogenesis imperfecta

Question 22

Teeth are covered by only a thin layer of abnormally formed enamel through which yellow underlying dentin is seen

Answer 22

Amelogenesis imperfecta

Question 23

T/F Susceptibility to caries is low in Amelogenesis Imperfecta

Answer 23

T

Question 24

Main problem in amelogenesis imperfecta

Answer 24

Enamel is subject to destruction from abrasion

Question 25

Management of amelogenesis imperfecta

Answer 25

Complete coverage of the crown for dentin protection, to reduce tooth sensitivity, and for improved appearance

Question 26

Odontoblasts fail to differentiate normally resulting in poorly calcified dentin

Answer 26

Dentinogenesis imperfecta

Question 27

Enamel-dentin junction is altered, causing enamel to break away

Answer 27

Dentinogenesis imperfecta

Question 28

Opaque white patches or horizontal lines on the tooth

Answer 28

Hypocalcification

Question 29

Pitting or areas devoid of enamel

Answer 29

Hypoplasia

Question 30

Mottled enamel

Answer 30

Fluorosis

Question 31

Fluorosis can result from systemic fluoride consumption ___ amount during enamel formation

Answer 31

>0.05mg/kg/day

Question 32

Fluorosis can be caused by

Answer 32

1) Residing in an area of high fluoride content of drinking water >2.0ppm 2) Swallowing excessive fluoridated toothpaste 3) Inappropriate fluoride prescriptions

Question 33

Fluorosis presents clinically as

Answer 33

Inconspicuous white, lacy patches on the enamel to severe brownish discoloration and hypoplasia

Question 34

Severe brownish discoloration and hypoplasia in severe fluorosis are usually seen with fluoride concentrations in the drinking water > ___

Answer 34

5.0ppm

Question 35

Neonatal condition that can produce blue to black discoloration of the primary teeth

Answer 35

Hyperbilirubinemia

Question 36

Produces red-brown discoloration of teeth

Answer 36

Porphyria

Question 37

If administered during the period of enamel formation, this can result in brown-yellow discoloration and hypoplasia of enamel

Answer 37

Tetracyclines

Question 38

Cause teeth to fluoresce under UV light

Answer 38

Tetracyclines

Question 39

Period at risk for discoloration and hypoplasia due to tetracycline use

Answer 39

4 months of gestation to 7 years of life

Question 40

Conditions associated with delayed eruption of the 20 primary teeth

Answer 40

1) Familial 2) Hypopituitarism 3) Hypothyroidism 4) Cleidocranial dysplasia 5) Trisomy 21

Question 41

Premature loss of primary teeth is MCC by

Answer 41

Premature eruption of permanent teeth

Question 42

If the entire dentition is advanced for age and sex, ___ or ___ should be considered

Answer 42

1) Precocious puberty 2) Hyperthyroidism

Question 43

Natal teeth are observed in approx 1 in 2000 newborns in the position of the

Answer 43

Mandibular central incisors

Question 44

Teeth that are present at birth

Answer 44

Natal teeth

Question 45

Teeth that erupt in the 1st month of life

Answer 45

Neonatal teeth

Question 46

Teeth whose attachment are limited to the gingival margin, with little root formation or bony support

Answer 46

Natal and neonatal teeth

Question 47

T/F A radiograph can differentiate between a supernumerary and prematurely erupted primary tooth

Answer 47

T

Question 48

T/F A family history of natal or premature eruption is present in affected children

Answer 48

T

Question 49

Exfoliation failure occurs most commonly in what region

Answer 49

Mandibular incisor