Tooth Development

Question 1

Cell layer of the bell stage that plays a supportive function in enamel production

Answer 1

Stellate reticulum

Question 2

Stage of tooth development that includes maturation

Answer 2

Maturation

Question 3

____ is comprised of multiple, small tooth-like structures

Answer 3

Compound Odontoma

Question 4

_____ is the junction of the outer and inner enamel epithelia; site of cemento-enamel junction (CEJ) in the adult tooth

Answer 4

Cervical loop

Question 5

____ formations stops at the termination of the enamel organ

Answer 5

Enamel

Question 6

_____ is the most common neoplastic lesion arising from odontogenic epithelium; considered a slow growing, locally invasive tumor; lesions have a multilocular or soap bubble appearance on radiographs

Answer 6

Ameloblastoma

Question 7

Cell layer of the bell stage outer cells differentiate into odontoblasts, whereas inner cell differentiate into pulp tissue

Answer 7

Dental papilla

Question 8

Ectoderm invaginates into the mesenchyme and is now called _____; separated from the surrounding mesenchyme by a basement membrane

Answer 8

Dental lamina

Question 9

____ is the most common manifestation of supernumerary tooth formation

Answer 9

Mesodens

Question 10

Cell layer of the bell stage that forms a protective barrier

Answer 10

Outer enamel epithelium

Question 11

Actively secreting ameloblasts are _____ cells

Answer 11

tall columnar cells

Question 12

_____ is an enlargement of the body and pulp chamber of multirooted teeth with apical displacement of the bifurcation; exceptionally long root trunk with very short roots; epithelial diaphragm with Hertwig’s root sheath malfunction

Answer 12

Taurodontism

Question 13

______ root is due to accelerated ortho or hertwig’s root sheath

Answer 13

Shorted root

Question 14

____ specifies the dental nature of mesenchyme

Answer 14

Epithelium

Question 15

Stage of tooth development that includes induction and proliferation

Answer 15

Apposition

Question 16

Stage of tooth development that includes proliferation, differentiation, and morphogenesis; this stage is considered the most important

Answer 16

Bell stage

Question 17

Stage of tooth development that includes cellular proliferation (growth)

Answer 17

Bud Stage

Question 18

_____ is the 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

Answer 18

Hertwig’s Epithelial Root Sheath

Question 19

Inactive ameloblasts are _____ or ____ cells

Answer 19

short columnar or elongated cuboidal cells

Question 20

____ is when tooth count is normal when the double tooth is counted as one

Answer 20

Gemination

Question 21

Abnormal _____ formation is due to an issue with epithelial diaphragm with Hertwig’s root sheath

Answer 21

Abnormal root formation

Question 22

A _____ is lined with epithelial cells with an open lumen

Answer 22

Cyst

Question 23

____ is a 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

Answer 23

Gemination

Question 24

____ is considered undifferentiated pulp and odontoblasts

Answer 24

Dental papilla

Question 25

____ formation continues of the enamel organ and pushes the tooth occlusally

Answer 25

Dentin

Question 26

____ originates by separation of the dental follicle (sac) from the crown of the unerupted tooth; cyst is attached at the CEJ; this cyst type comprises 20% of all jaw cysts

Answer 26

Dentigerous cyst

Question 27

Cyst wall consists of a 6-8 cell layer of stratified squamous epithelium with parakeratosis at the luminal surface; lumen is often filled with keratin; presence of inflammation will generally cause epithelial proliferation and palisading of the basal cell layer

Answer 27

Keratocystic Odontogenic Tumor or (OKC)

Question 28

______ specifies tooth type and nature of the product produced by the epithelium

Answer 28

Mesenchyme

Question 29

____ arises from the cells rests of the dental lamina; bone expanding cysts; located mostly in the posterior mandible often present as multilocular lesions; 60% of all cases between the ages of 10-40; 65% of cases are located in mandible; there is a 30% recurrence rate after surgical removable

Answer 29

Keratocystic Odontogenic Tumor or (OKC)

Question 30

_____ plays a supportive role to hold shape of the enamel organ

Answer 30

Stellate reticulum

Question 31

____ refers to the total lack of tooth development

Answer 31

Anodontia

Question 32

_____ is more proteinaceous not yet calcified

Answer 32

Enamel matrix

Question 33

_____ dictates what the group of cells will form; plays an instructional role during the pre-tooth bud stage of tooth formation

Answer 33

Epithelium

Question 34

____ is defined as an abnormal angulation or bend in root; Hertwig's root sheath bend

Answer 34

Dilaceration

Question 35

____ is the 1st formed dentin, 30-50 microns thick, contains both type 1 and 3 collagen, and collagen fibers in the matrix are oriented perpendicular to the DEJ

Answer 35

Mantle dentin

Question 36

_____ stimulates ameloblasts to separate enamel matrix

Answer 36

Mantle dentin

Question 37

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

Answer 37

Hyperdontia

Question 38

Root length is not complete until _____ years after the tooth has emerged into the oral cavity; pulp chamber narrows and apical opening constricts

Answer 38

1-3 years

Question 39

At what stage are all the layers of the enamel organ identifiable?

Answer 39

Bell stage

Question 40

At the final stage of mineralization, the reduced ameloblasts with the remaining cells of the outer enamel epithelium, stellate reticulum, and stratum intermedium form a membrane on the surface of the enamel; squishes all layers of enamel epithelium, stellate reticulum, and stratum intermedium

Answer 40

Primary cuticle

Question 41

____ refers to a double tooth in which the tooth count reveals a missing tooth when the double tooth is counted as one

Answer 41

Fusion

Question 42

_____ is a defect that originates during initiation stage that results in development of one or more extra teeth

Answer 42

Supernumerary teeth

Question 43

____ originates during the initiation stage and results in multiple small fragments of tooth structure consisting of dentin, enamel, cementum, or any combination

Answer 43

Odontoma

Question 44

____ encapsulates enamel organ and turns in the PDL, cementum, and alveolar bone

Answer 44

Dental follicle (sac)

Question 45

Cell layer of the bell stage that differentiate into cementum, PDL, and alveolar bone

Answer 45

Dental sac

Question 46

During this stage, the fate of neural crest cells (mesenchyme) has yet to be fully determined

Answer 46

Pre-tooth bud stage

Question 47

Stage of tooth development that includes cellular induction

Answer 47

Initiation

Question 48

_____ indicates the lack of formation of 6 or more teeth

Answer 48

Oligodontia

Question 49

Stage of tooth development that includes proliferation, differentiation, and morphogenesis

Answer 49

Cap Stage

Question 50

____ denotes the lack of development of one or more teeth

Answer 50

Hypodontia

Question 51

____ is a defect occurring during apposition and maturation stages that results in union of root structure of 2 or more teeth by cementum

Answer 51

Concrescence

Question 52

Cell layer of the bell stage that differentiate into ameloblasts

Answer 52

Inner enamel epithelium

Question 53

____ is comprised of a conglomerate mass of enamel and dentin that bears no anatomic resemblance to a tooth; locally invasive

Answer 53

Complex odontoma

Question 54

_____ is the modification of Hertwig's Sheath creating septa that divide the pupal tissue and create multiple roots

Answer 54

Epithelial diaphragm

Question 55

Cell layer of the bell stage that plays a supportive function; produces alkaline phosphatase to help minimize matrix

Answer 55

Stratum Intermedium

Question 56

_____ is a defect occurring during cap stage of development that results in an extra cusp due to effects on enamel organ

Answer 56

Tubercle formation