Tooth Development

Question 1

At what stage can all layers of the enamel organ be differentiated?

Answer 1

Bell stage

Question 2

In the adult tooth, the cervical loop determines the location of the _________

Answer 2

Cemento-enamel junction (CEJ) aka cervix

Question 3

The cervical loop is comprised of which 2 cellular layers?

Answer 3

IEE and OEE

Question 4

Which cell layers combine to form the “enamel organ”?

Answer 4

a. Outer enamel epithelium
b. Stellate reticulum
c. Stratum intermedium
d. Inner enamel epithelium —> ameloblasts

Question 5

A dilaceration is caused by a deviation in growth of which structure?

Answer 5

Hertwig’s root sheath

Question 6

Hertwig’s epithelial root sheath is formed by the fusion of which 2 cellular layers?

Answer 6

IEE and OEE

Question 7

The dental follicle differentiates into which adult structures?

Answer 7

a. Alveolar bone
b. Periodontal ligament
c. Cementum

Question 8

Embryologically, the “enamel organ” is derived from which germ layer?

Answer 8

ectoderm

Question 9

With respect to the tooth root, the epithelial diaphragm determines their _______

Answer 9

number of roots

Question 10

With respect to the tooth root, Hertwig’s epithelial root sheath determines their ______

Answer 10

length and shape of roots

Question 11

The stratum intermedium secretes _______, an enzyme required for enamel matrix mineralization

Answer 11

Alkaline phosphatase

Question 12

Nasmyth’s membrane consists of which cell layers?

Answer 12

a. Reduced ameloblasts (IEE)
b. Outer enamel epithelium
c. Stellate reticulum
d. Stratum intermedium

Question 13

A __________ is the most common manifestation of a supernumerary tooth.

Answer 13

Mesodens (peg shape between max central incisors)

Question 14

A(n) _________ is comprised of enamel and dentin arranged in a way that bears no anatomic resemblance to teeth

Answer 14

Complex odontoma (complex looks nothing like tooth)

Question 15

The Dentigerous cyst comprises ____% of all jaw cysts and is always associated with
a/an _______.

Answer 15

a. 20%
b. Unerupted tooth, attached to the CEJ

Question 15

A developmental cyst occurring along the lateral aspect of the neck is most likely a
__________.

Answer 15

Lateral cervical cyst… follows sternocleidomastoid

Question 16

Most odontogenic keratocysts (OKC’s) occur in the _____________ part of the mandible

Answer 16

Posterior

Question 17

Upon biopsy, the lumen of an odontogenic keratocyst is characterized by the presence of ____________.

Answer 17

keratin

Question 18

the most common neoplastic lesion of the jaws, arising from odontogenic epithelium is the ________

Answer 18

Ameloblastoma

Question 19

Nasmyth’s membranes is also known as the _________

Answer 19

primary (enamel) cuticle

Question 20

Match the cell layers of the enamel organ with their appropriate function/derivative

Answer 20

a. OEE= protective barrier for enamel organ
b. -Stellate reticulum= supportive fnct in enamel production
c. Stratum intermedium= secretes alkaline phosphatase
d. IEE= differentiates into Ameloblasts
e. Peripheral cells of dental papilla= differentiates into odontoblasts