EX2; Eruption and Shedding Flashcards
What are the three stages of eruptions
preemergence
prefunctional
functional
What is the main direction of movement in the preemergence stage
facially
What is the main direction of movement in the prefunctional stage
occlusially
What is the main direction of movement in the functional stage
mesially
This stage starts with the appearance of dental lamina and continues to the appearance of reduced enamel epithelium and Hertwig’s root sheath, just prior to the start of root dentin formation
preemergence stage
This is the movements a tooth makes to attain and maintain its position in the jaw
eruption
Which is the only direction in which the tooth will not move
apically
The movements of eruption are a cellular activity involving different cell types of the periodontal ligament; which are
cementoblasts
osteoblast
osteoclast
fibroblast
This is the most numerous cell type of the PDL, involved in the secretion(blast) and lysis(coast) of the extracellular substance, and may become a contracting cell
fibroblast/clast/myocyte (myofibroblast)
What is the main direction of movement of the primary and secondary tooth germ
facially
What is the reduced enamel epithelium attached to the enamel surface by
basal lamina
What are the two main functions of Hertwig’s root sheath
determines the number of root canals and the root dentin outline
What is the bone crypt
become the alveolar process
This stage starts with root dentin formation and ends when tooth reached the occlusal plane
prefunctional stage of eruption
What is the main direction of movement of the pre functional stage
occlusially
What does the apical end of Hertwigs epithelial sheath continue as
the diaphragm; determining the number of root canals
Where is the reduced enamel epithelium in relation to Hertwig’s root sheath
it is over/above it
During the root sheath diagram stage, what happens
the number of root canals is determined
tooth erupts occlusially from this level
During the root sheath elongating, what happens
determines root dentin outline
diaphragm remains at the relatively same level
What happens upon the root dentin forming
the sheath breaks up; cementum forms on exposed dentin
These are remnants of epithelial cells from Hertwig’s root sheath in the periodontal ligament, appearing during the pre functional stage of eruption
Epithelial rest of Malassez
During the pre functional stage, what happens to the merged oral epithelium and the reduced enamel epithelium
they undergo cell death
What does the reduced enamel epithelium become
junctional epithelium
The basal lamina is considered this type of basement membrane
“double” basement membrane
it extended around the entire junctional epithelium
True or False
the basal lamina can attach to dentin
False; this also affects implants
What is the arrangement of collagen fiber bundles of the PDL
onliquely
This stage starts at the occlusal plane and physiologically continues throughout life
functional stage
What is the main movement in the functional stage
mesially
What are the changes to the junctional epithelium during functional eruption
attached to enamel
attached to enamel and cementum
attached to cementum
Functional arrangement of the principal fiber bundles of PDL occurs during which stage
functional stage
During the functional stage, what changes occur to dentin
attrition
dead tracts
reparative (tertiary) dentin
What are the changes during the functional stage of eruption
continued dentin formation
reduced pulp tissue volume
ectopic mineralization
This is the physiologic elimination of primary teeth caused by the resportive action of osteoclasts
shedding
Where does the odontoclast originate
in the bone marrow
If the reduced enamel epithelium comes in close contact to the osteoclast cells, what could occur
it could break down and cause the enamel to damage
