PEDO pt 1 Flashcards
(138 cards)
initiation (bud stage) of primary teeth occurs in week ___ of embryonic life
6
which teeth arise from the dental lamina? where do the other teeth arise from?
- all primary teeth and permanent molars
- all permanent incisors, canines, and premolars arise from their primary predecessor
failure of what stage of development results in congenitally missing teeth?
- initiation (bud stage)
- alternatively, excessive budding results in supernumerary teeth
what are the stages, in order, of tooth development?
- initiation (bud stage)
- proliferation (cap stage)
- histodifferentiation and morphodifferentiation (bell stage)
- apposition
- calcification
during the proliferation (cap) stage, peripheral cells of the cap form the ___ and ___
inner and outer enamel epithlium
failure in the proliferation results in ___
congenitally missing teeth
excessive proliferation results in ___
a cyst, odontoma, or supernumerary tooth, depending on the amount of cell differentiation
during the histodifferentiation and morphodifferentiation (bell) stage, cells of the dental papilla differentiate into ___, and cells of the inner enamel epithelium differentiate into ___
- odontoblasts
- ameloblasts
failure in histodifferentiation results in ___, and failure in morphodifferentiation results in ___
- structural abnormalities of the enamel and dentin (amelogenesis imperfecta, dentinogenesis imperfecta)
- size and shape abnormalities, such as peg lateral incisors and macrodontia
what happens during the apposition stage?
ameloblasts and odontoblasts deposit a layerlike matrix
disturbances in apposition result in ___
- incomplete tissue formation
- for example, an intrusive injury to a primary incisor may disrupt enamel apposition and result in an area of enamel hypoplasia
enamel is composed of ___% inorganic material and ___% organic material and water
96%, 4%
where does calcification begin?
begins at cusp tips and incisal edges and proceeds cervically
what can cause hypocalcification?
localized infection, trauma, and excessive systemic fluoride ingestion
what are the approximate calcification times for primary teeth?
- central incisor 14 weeks in utero
- first molar 15 weeks in utero
- lateral incisor 16 weeks in utero
- canine 17 weeks in utero
- second molar 18 weeks in utero
what are the approximate maxillary eruption times for primary teeth?
- central incisor 10 months
- lateral incisor 11 months
- first molar 16 months
- canine 19 months
- second molar 29 months
- a 6 month variation in eruption time is considered normal
what are the approximate mandibular eruption times for primary teeth?
- central incisor 8 months
- lateral incisor 13 months
- first molar 16 months
- canine 20 months
- second molar 27 months
- a 6 month variation in eruption time is considered normal
what are the approximate calcification times for permanent maxillary teeth (excluding 3rd molars)?
- first molar birth
- central incisor 3-4 months
- canine 4-5 months
- lateral incisor 10-12 months
- first premolar 1.5 years
- second premolar 2 years
- second molar 2.5 years
what are the approximate calcification times for permanent mandibular teeth (excluding 3rd molars)?
- first molar birth
- central incisor 3-4 months
- lateral incisor 3-4 months
- canine 4-5 months
- first premolar 1.75 years
- second premolar 2.25 years
- second molar 2.75 years
what are the average eruption times for maxillary permanent teeth?
phone number: 781-0062
what are the average eruption times for mandibular permanent teeth?
phone number: 679-0161
eruption of a tooth begins when the crown has completed ___
calcification
typically, it takes ___ years for most crowns to complete formation except for first molars and cuspids, which take how long?
- 4-5 years
- first molars take 3 years
- cuspids take 6 years
it takes approximately ___ years from start of calcification to root completion, except for canines, which take how long?
- 10 years
- canines take 13 years