Embryology- Ch 6 Tooth Dev Questions

Front 1

when does odontogenesis begin

Back 1

6th and 7th weeks

Front 2

when does the initiation stage of odontogenesis occur?

Back 2

6th and 7th weeks

Front 3

what physiological process occurs during the initiaion stage?

Back 3

induction (interaction between the ectoderm cells and the mesenchyme cells- this must occur before odontogenesis can begin)

Front 4

from where is oral epithelium derived?

Back 4

ectoderm

Front 5

from where do neural crest cells originate?

Back 5

from the neuroectoderm and the ectoderm before that

Front 6

during which week is the stomodeum lined with ectoderm (which will give rise to oral epithelium)?

Back 6

week 6

Front 7

what is directly under the oral epithelium?

Back 7

a type of mesenchyme that originally came from the ectoderm called ectomesenchyme- this is influenced by neural crest cells that have migrated to the area

Front 8

what seperates the oral epithelium and mesenchyme?

Back 8

basement membrane

Front 9

During the end of week 7, the OE grows deeper into the ectomesenchyme and is induced to create a layer called.......?

Back 9

Dental lamina

Front 10

What is the cause of adontia?

Back 10

LACK of initiation within the dental lamina during the initiation stage

Front 11

Which teeth are most commonly affected by partial adontia?

Back 11

permanent max lat insicors, 3rd molars, mand 2nd premolars

Front 12

ABNORMAL initiation during the initiation stage results in what developmental disturbance?

Back 12

supernumerary teeth (hyperdontia)

Front 13

what are the most common areas for supernumary teeth to form?

Back 13

between max centrals (mesiodens), distal to max 3rd molars (distomolar or 4th molar), in premolar regions of both arches

Front 14

ectodermal dysplasia is associated with which developmental disturbance?

Back 14

adontia. many parts of the tooth are indirectly or directly of ectodermal origin

Front 15

ectodermal displasia causes defects in which areas?

Back 15

hair, nails, sweat glands, teeth, lens of eye, parts of inner ear, fingers and toes, nerves

Front 16

where are supernumary teeth initiated from?

Back 16

dental lamina

Front 17

When does the bud stage occur?

Back 17

week 8

Front 18

what physiological process occurs during the bud stage?

Back 18

proliferation (of dental lamina buds penetrating into the mesenchyme) (underlying mesenchyme also undergoes proliferation)

Front 19

The tooth bud surrounding the mesenchyme will develop into what during the bud stage?

Back 19

a tooth germ and its associated supporting tissues

Front 20

all teeth and their associated structures develop from what?

Back 20

ectoderm and mesenchyme (specifically ectomesenchyme which is influenced by neural crest cells)

Front 21

At the end of the proliferation process of the bud stage what is in place?

Back 21

10 buds each on the future max and mand arches

Front 22

what structure seperates the buds and the ectomesenchyme during the bud stage?

Back 22

basement membrane

Front 23

proliferation of which tissue types occurs during the bud stage?

Back 23

dental lamina (from the oral epithelium which comes from the ectoderm) and ectomesenchyme

Front 24

what STRUCTURAL changes occur in the cells of the ecotmesenchyme and the dental lamina during the bud stage?

Back 24

no structural changes occur during the bud stage, ONLY proliferation

Front 25

what developmental disturbances occur during the bud stage?

Back 25

macrodontia and microdontia

Front 26

what causes microdontia and macrodontia?

Back 26

abnormal proliferation during the bud stage

Front 27

what causes macrodontia?

Back 27

too much proliferation during the bud stage

Front 28

what causes microdontia?

Back 28

not enough proliferation during the bud stage

Front 29

which teeth are commonly affected by microdontia?

Back 29

perm max laterals (peg laterals) and perm 3rd molars (peg molars)

Front 30

when does the cap stage occur?

Back 30

weeks 9-10

Front 31

what physiological processes occur during the cap stage?

Back 31

proliferation, differentiation, morphogenesis

Front 32

what is the PREDOMINANT physiological process to occur during the cap stage?

Back 32

morphogenesis

Front 33

What are the 3 parts of the tooth germ?

Back 33

tooth germ= enamel organ, dental papilla, dental sac. tooth germs develop during the cap stage

Front 34

from what is the enamel organ derived?

Back 34

ectoderm

Front 35

from what is the dental papilla derived?

Back 35

mesenchyme

Front 36

what will the dental papilla produce?

Back 36

dentin and pulp

Front 37

from what is the dental sac (AKA dental follicle) derived?

Back 37

mesenchyme (specifically ectomesenchyme which is influenced by neural crest cells)

Front 38

what will the dental sac produce?

Back 38

the periodontium- cementum, PDL, alveolar bone

Front 39

during what stage of odontogenesis does the enamel organ, dental papilla, and dental sac form?

Back 39

cap stage (weeks 9-10)

Front 40

where is the basement membrane during the cap stage and what will it become?

Back 40

between enamel organ and dental papilla and will be the future site of the DEJ. basement membrane also seperates enamel organ from the dental sac

Front 41

evidence of a developing permanent tooth can be seen during which week?

Back 41

week 10

Front 42

developing perm teeth are where in relation to developing primary teeth?

Back 42

lingual, they appear as an extension of the dental lamina into the ectomesenchyme

Front 43

what developmental disturbances occur during the cap stage (weeks 9-10)?

Back 43

dens in dente, gemination, fusion, tubercles

Front 44

what causes dens in dente?

Back 44

enamel organ invaginates into dental papilla during the cap stage (weeks 9-10)

Front 45

what causes gemination?

Back 45

a single tooth germ attempts to divide during the cap stage (weeks 9-10)

Front 46

what causes fusion?

Back 46

union of 2 adjacent tooth germs during the cap stage (weeks 9-10)

Front 47

what causes a tubercle?

Back 47

defect in the enamel organ during the cap stage (weeks 9-10)

Front 48

when does the bell stage occur?

Back 48

weeks 11-12

Front 49

what are the 4 parts of the enamel organ apparent in the bell stage (weeks 11-12)?

Back 49

inner enamel epithelium, outer enamel epithelium, stellate reticulum, stratum intermedium

Front 50

which parts of the enamel organ support the producton of enamel?

Back 50

stellate reticulum and stratum intermedium

Front 51

what physiological processes occur during the bell stage?

Back 51

proliferation, differentiation, morphogenesis

Front 52

what part of the enamel organ will differentiate into ameloblasts?

Back 52

inner enamel epithelium

Front 53

what part of the enamel organ protects the enamel organ during enamel production?

Back 53

outer enamel epithelium

Front 54

the dental papillla undergoes extensive differentiation during the bell stage (weeks 11-12) to form which 2 tissue types?

Back 54

outer cells of the dental papilla and central cells of the dental papilla

Front 55

what will the outer cells of the dental papilla differentiate into?

Back 55

odontoblasts

Front 56

what will the central cells of the dental papilla differentiate into?

Back 56

pulp

Front 57

what occurs during the apposition stage?

Back 57

induction, proliferation

enamel, dentin and cemetum are secreted

Front 58

when is the stage of maturation reached?

Back 58

when the matrices of the hard deposits are fully mineralized

Front 59

what is the function of the basement membrane during the apposition stage?

Back 59

communicates between ectoderm of enamel and mesenchyme of dental papilla and dental sac to allow for induction needed for production of tooth structures

Front 60

what is the process of ameloblast and odontoblast formation?

Back 60

inner enamel epithelium of enamel organ differentiate into preameloblasts, preameloblasts induce outer cells of the dental papilla to diff. into odontoblasts, odontoblasts secrete predentin, basement membrane disintegrates, predentin induces preameloblasts to diff. into ameloblasts, ameloblasts secrete enamel

Front 61

where is the enamel matrix secreted from?

Back 61

Tomes process (terminal end of ameloblast)

Front 62

what developmental disturbances occur during apposition and maturation stages?

Back 62

enamel pearls, enamel dysplasia, enamel hypoplasia (hutchinsons incisors, mulberry molars), enamel hypocalcification, amelogenesis imperfecta, dental fluorsis, dentinal dysplasia, concresence,