Tooth Development

Question 1

What is the tooth anatomy structures

Answer 1

Enamel
Dentin
Cementum
pulp

Question 2

What is periodontium made of?

Answer 2

Gingiva
Periodontal ligament
Cementum
Alveolar bone proper

Question 3

Initiation ->
Bud stage ->
Cap stage -> 
Bell stage ->
Apposition ->
Maturation ->

Answer 3

Cellular induction
Cellular proliferation
Proliferation, differentiation, and morphogenesis
Proliferation, differentiation, and morphogenesis
Induction and proliferation
Maturation

Question 4

Epithelium (ectoderm) plays an “instructional” role during what stage of tooth formation

Answer 4

Pre-tooth bud stage

Question 5

Epithelium specifies the “dental mature” of what

Answer 5

the mesenchyme

Question 6

The mesenchyme specifies the ____ ____ and nature of the product produced by the epithelium (enamel matrix)

Answer 6

Tooth type (incider vs. molar)

Question 7

Steps to tooth development starting with primitive oral ectoderm

Answer 7

primitive oral ectoderm -> enamel organ -> outer dental epithelium -> stellate reticulum -> stratum intermedium -> inner dental epithelium -> ameloblasts -> enamel

Question 8

Lamina is separated from the surrounding mesenchyme by

Answer 8

A basement membrane

Question 9

Ectoderm invaginate into the mesenchyme and is now called the

Answer 9

Dental lamina

Question 10

During induction what is working?

Answer 10

Oral ectoderm (epithelium)
Early dental lamina

Question 11

During bud stage what is working?

Answer 11

8th wk
Apoptosis
Oral ectoderm
Dental lamina

Question 12

During early cap stage what is working?

Answer 12

Apoptosis resulting in creation of buccal vestibule.
Dental lamina
Outer dental epithelium
Early stellate reticulum

Question 13

During cap stage what is working?

Answer 13

Dental lamina
Enamel organ 
- Outer enamel epithelium
- Stellate reticulum (loosely packed cells): holds shape
- Inner enamel epithelium

Question 14

During cap stage what is working?

Answer 14

Oral ectoderm
Dental lamina
Stellate reticulum
Outer enamel epithelium
Inner enamel epithelium
Dental papilla
Dental follicle (aka dental sac)
Cervical loop

Question 15

During bell stage what is working?

Answer 15

All layers of the enamel organ can be differentiated

Question 16

O.E.E - Outer epithelium

Answer 16

Cuboidal cells

Protective barrier

Question 17

I.E.E - inner epithelium

Answer 17

Cuboidal cells

Differentiate into ameloblatsts

Question 18

Stellate reticulum

Answer 18

Star-shaped cells forming network inside enamel organ

Supportive function in enamel production

Question 19

Stratum Intermedium

Answer 19

Compressed layer of flat cuboidal cells

Supportive function in enamel production

Question 20

Dental sac

Answer 20

Collagen fibers around enamel organ

Differentiate into cementum, PDL and bone

Question 21

Dental papilla

Answer 21

Cells nearest IEE have basement membrane separation

Outer cells differentiate into odontoblasts, whereas inner cells differentiate into pulp tissue

Question 22

Cervical loop

Answer 22

Junction of the outer & inner enamel epithelia.

Site of cemento-enamel junction (CEJ) in the adult tooth (aka cervix)

Question 23

Root Development

Answer 23

Cervical loop
Stellate reticulum
stratum intermedium
pre-odontoblasts

Question 24

Hertwigs epithelial root sheath

Answer 24

Fusion and apical extension of the outer and inner enamel epithelia. Determines the outline of the root dentin and the number of roots a tooth will have. It is removed before the cementum is laid down

Question 25

Enamel formation stops at the termination of the

Answer 25

enamel organ, although dentin formation centimes and pushes the tooth occlusally

Question 26

Root length is not complete until

Answer 26

1-4 yrs after the tooth has emerged into the oral cavity. The pulp chamber narrows and the apical opening constricts

Question 27

Apposition stage

Answer 27

Stellate reticulum Stratum intermedium (produces alkaline phosphatase) Inner enamel epithelium -> ameloblasts -> enamel Peripheral cells of dental papillae -> odontoblasts -> dentin

Question 28

Mantle dentin

Answer 28

``` 1st formed dentin 30-50mM thick Contains both type 1 and 3 collagen Collagen fiber in the matrix are oriented perpendicular to the DEJ Stimulates amelblasts to make enamel ```

Question 29

Migration of ameloblasts moves _____ | Migration of odontoblasts moves ______

Answer 29

Peripherally | Inward (centrally)

Question 30

What is actively secreting ameloblasts

Answer 30

tall columnar cells

Question 31

After completion, inactive (aka reduced) ameloblasts are _____ __ _____ _____ ____

Answer 31

Short columnar or elongated cuboidal cells

Question 32

What happens at the final stage of mineralization

Answer 32

the reduced amelblasts with the remaining cells of the outer enamel epithelium, stellate reticulum and stratum intermedium form a membrane on the surface of the enamel - primary cuticle

Question 33

Anodontia

Answer 33

refers to the total lack of tooth development - no teeth at all

Question 34

Hypodontia

Answer 34

denotes the lack of development of one of more teeth

Question 35

Oligodontia

Answer 35

indicates the lack of formation of six or more teeth (a subdivision of hypodontia)

Question 36

Hyperdontia

Answer 36

the development of an increased number of teeth (the additional teeth are termed supernumerary)

Question 37

Supernumerary teeth

Answer 37

Defect that originates during initiation stage that results in development of one or more extra teeth

Question 38

Unilateral supernumerary bicuspids can be within families

Answer 38

brother had it and brother

Question 39

Mesodens

Answer 39

the most common manifestation of supernumerary tooth formation - btw central incisors

Question 40

Odontoma

Answer 40

originates during initiation stage and results in multiple small fragments of tooth structure consisting of dentin, enamel, cementum or any combination - extra growth with no distinct pattern

Question 41

Complex odontoma

Answer 41

Comprised of a conglomerate mass of enamel and dentin that bears no anatomic resemblance to a tooth - have to remove bc they tend to grow

Question 42

Compound odotoma

Answer 42

Comprised of multiple, small tooth-like structures

Question 43

Taurodontism

Answer 43

an enlargement of the body and pulp chamber of multicoated teeth with apical displacement of the bifurcation (an exceptionally long root trunk with very short roots)

Question 44

Dilaceration

Answer 44

defined as an abnormal angulation or bend in the root

Question 45

Gemination

Answer 45

Defect that originates during cap stage of development that results in large single-rooted tooth with one pulp cavity and exhibits "twinning" in crown area

Question 46

Gemination

Answer 46

Tooth count is normal when the double tooth is counted as one. 1 large single root, 1 pulp cavity, but "2 crowns" it tries to split and be 2

Question 47

Fusion

Answer 47

Refers to a double tooth in which the tooth count reveals a missing tooth when the double tooth is counted as one. 2 tooth: 2 RCs try to become 1

Question 48

How do you tell gemination and fusion apart

Answer 48

count all the teeth and if you are missing 1 = fusion and if normal = gemination

Question 49

Concrescence

Answer 49

Defet occurring during apposition and maturation stages that results in union of root structure of two or more tooth be cementum

Question 50

Tubercle formation

Answer 50

Defect occurring during cap stage of development that results in an extra cusp due to effects on enamel organ

Question 51

Dentigerous cyst (aka follicular cyst)

Answer 51

originates by separation of the dental follicle (dental sac) from the crown of an unerupted tooth. The cyst is attached to the CEJ. This cyst type comprises 20% of all jaw cysts

Question 52

Odontogenic Keratocyst (OKC)

Answer 52

Arises from the cells rests of the dental lamina (or rests of serres). Bone expanding cysts. Located in the posterior mandible often present as multilocular lesions. Surgical removal is the treatment of choice.

Question 53

Cyst wall consists of

Answer 53

a 6-8 cell layer of stratified squamous epithelium with parakeratosis at the luminal surface. The lumen is often filled with keratin. The presence of inflammation with generally cause epithelial proliferation and passisading of the basal cell layer

Question 54

Ameloblastoma

Answer 54

The most common neoplastic lesion arising from odontogenic epithelium. A slow growing, locally invasive tumor. Lesions have a multilocular or "soap bubble" appearance on radiographs. The tumors are radio-resistant - must be surgically removed.