primary tooth morphology Flashcards
what early problems can occcur?
gingival cysts
congenital epulis
natal/neonatal teeth
eruption cysts
describe a gingival cyst
white
on gingivae
keratin
what should you do if you see a gingival cyst?
reassure parents
no tx needed
keep under observation
when should you treat congenital epulis?
only if large and interferes with feeding
describe natal/neonatal teeth
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
what is an eruption cyst?
blue
overlying developing tooth about to erupt
filled with blood
resolves as tooth erupts
when do teeth start to form?
week 5 of IUL
when does hard tissue formation begin?
week 13 IUL
can be detected on ultrasound
describe the formation of the central incisors
start cal. 13-16 wk IUL
crown complete 1.5 months after birth
eruption 8-12 months
root complete 33 months
describe the formation of the second primary molar
hart tissue formation 16-23 wks IUL
crown formation complete at 11 months after birth
eruption 25-33 months
complete root formation 47 months
what can cause defects in enamel?
systemic disturbances during calcification - enamel formed at that time
what amount of each tooth is calcified at birth?
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
what is the order of eruption?
lowers first except lateral incisors
ABDCE
12435
what is usually the first tooth to erupt?
lower central incisor 4-6months
when does the lateral incisor erupt?
7-12 months
when does the 1st molar erupt?
13-19 months
when does the canine erupt?
16-22 months
when does the 2nd molar erupt?
15-33 months
what are the differences between primary and permanent teeth (crowns)
primary incisors smaller
primary molars wider mesiodistally than premolars
primary molar crowns more bulbous
primary teeth whiter
what is an anatomical feature of the 1st molar?
prominent mesiobuccal tubercle
how many buccal cusps are there in the 2nd primary molars
3
what are the root differences between the primary and permanent teeth?
narrower
molars longer and more slender
flare apically
describe the pulp differences between primary and permanent teeth
large in proportion to crowns
extend high occlusally
-closer to enamel
describe primary root canals
ribbon shaped with multiple interconnecting and accessory canals
describe the difference in enamel
primary relatively thin and consistent depth
describe difference in dentine
coronal dentine much thinner than in permanent teeth
what is leeway space?
extra mesio-distal space occupied by primary molars which are wider than the premolars which will replace them
when does the mixed dentition stage occur?
begins from 1st permanent tooth erupts until exfoliation of last primary tooth
usually 6-11 years
what is the eruption sequence of upper permanent teeth?
6,1,2,4,5,3,7,8
what is the eruption sequence of the lower permanent teeth?
6,1,2,3,4,5,7,8
why does transient spacing occur?
upper 1s due to close proximity of roots to 2&3’s
self corrects after canines erupt
