primary tooth morphology

Question 1

what early problems can occcur?

Answer 1

gingival cysts
congenital epulis
natal/neonatal teeth
eruption cysts

Question 2

describe a gingival cyst

Answer 2

white
on gingivae
keratin

Question 3

what should you do if you see a gingival cyst?

Answer 3

reassure parents
no tx needed
keep under observation

Question 4

when should you treat congenital epulis?

Answer 4

only if large and interferes with feeding

Question 5

describe natal/neonatal teeth

Answer 5

before/in first few weeks of life
primary central incisors
ectopic position=early eruption
can cause ulcer under tongue
no tx unless ulcer causing or if very mobile
root not formed
danger to airway
smooth down/may extract

Question 6

what is an eruption cyst?

Answer 6

blue
overlying developing tooth about to erupt
filled with blood
resolves as tooth erupts

Question 7

when do teeth start to form?

Answer 7

week 5 of IUL

Question 8

when does hard tissue formation begin?

Answer 8

week 13 IUL

can be detected on ultrasound

Question 9

describe the formation of the central incisors

Answer 9

start cal. 13-16 wk IUL
crown complete 1.5 months after birth
eruption 8-12 months
root complete 33 months

Question 10

describe the formation of the second primary molar

Answer 10

hart tissue formation 16-23 wks IUL
crown formation complete at 11 months after birth
eruption 25-33 months
complete root formation 47 months

Question 11

what can cause defects in enamel?

Answer 11

systemic disturbances during calcification - enamel formed at that time

Question 12

what amount of each tooth is calcified at birth?

Answer 12

1/2 central incisors
1/3 lateral incisors
tip of canines
1/2 first primary molars
1/3 second molars
tip of cusps 1st permanent molars

Question 13

what is the order of eruption?

Answer 13

lowers first except lateral incisors
ABDCE
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Question 14

what is usually the first tooth to erupt?

Answer 14

lower central incisor 4-6months

Question 15

when does the lateral incisor erupt?

Answer 15

7-12 months

Question 16

when does the 1st molar erupt?

Answer 16

13-19 months

Question 17

when does the canine erupt?

Answer 17

16-22 months

Question 18

when does the 2nd molar erupt?

Answer 18

15-33 months

Question 19

what are the differences between primary and permanent teeth (crowns)

Answer 19

primary incisors smaller
primary molars wider mesiodistally than premolars
primary molar crowns more bulbous
primary teeth whiter

Question 20

what is an anatomical feature of the 1st molar?

Answer 20

prominent mesiobuccal tubercle

Question 21

how many buccal cusps are there in the 2nd primary molars

Answer 21

3

Question 22

what are the root differences between the primary and permanent teeth?

Answer 22

narrower
molars longer and more slender
flare apically

Question 23

describe the pulp differences between primary and permanent teeth

Answer 23

large in proportion to crowns
extend high occlusally
-closer to enamel

Question 24

describe primary root canals

Answer 24

ribbon shaped with multiple interconnecting and accessory canals

Question 25

describe the difference in enamel

Answer 25

primary relatively thin and consistent depth

Question 26

describe difference in dentine

Answer 26

coronal dentine much thinner than in permanent teeth

Question 27

what is leeway space?

Answer 27

extra mesio-distal space occupied by primary molars which are wider than the premolars which will replace them

Question 28

when does the mixed dentition stage occur?

Answer 28

begins from 1st permanent tooth erupts until exfoliation of last primary tooth
usually 6-11 years

Question 29

what is the eruption sequence of upper permanent teeth?

Answer 29

6,1,2,4,5,3,7,8

Question 30

what is the eruption sequence of the lower permanent teeth?

Answer 30

6,1,2,3,4,5,7,8

Question 31

why does transient spacing occur?

Answer 31

upper 1s due to close proximity of roots to 2&3’s

self corrects after canines erupt