Eruption and Shedding Flashcards
TERM – the movements a tooth makes to attain and maintain its position in the jaw
**From the tooth’s formative stages wintin the jaws to its functional stage in the oral cavity
Eruption
True or False?
A tooth will move all directions during eruption except apically
True
Name the 3 stages of tooth eruption
1.
2.
3.
- Pre-emergence
- Pre-functional
- Functional
Name the MAIN direction of tooth movement in each eruption stage
- Pre-emergence
- Pre-functional
- Functional
- Pre-emergence —— FACIALLY
- Pre-functional —– OCCLUSALLY
- Functional —– MESIALLY
A tooth will continue to erupt until it reaches the ___________ __________
Occlusal Plane
Review: Name the 4 stages leading to the enamel organ
- Dental Lamina
- Bud
- Cap
- Bell
During the pre-emergence stage, cells will concentrate at the apical end of the tooth germ called the ______ ______
Follicle Sac
After enamel is complete, 4 cell layers of enamel organ become 1 _____ _____ _____
Reduced Enamel Epithelium
What is the function of the REE?
Protects enamel during eruption
The cervial loop is where the outer and inner layers of enamel organ come together and form 2 _____ _____ ____ _____
Hertwig’s Epithelial Rooth Sheaths
The REE is attached to the enamel surface by a ______ _____
Basal Lamina
The REE is known as the last secretion of ______
Ameloblasts
Herwig’s epithelial rooth sheath determines 2 things:
1.
2.
- # root canals (not roots)
- Root dentin outline
True or False
Pre-emergence stage begins after root formation
FALSE
Pre-emergence stage begins BEFORE root formation
At what stage are the # of root canals determined?
Pre-emergence stage
Mandibular first molars have ____ root canals in the MESIAL root
Mandibular canines also can have ____ root canals in their single root
2
2
3 types of cells that differentiate during the pre-emergence stage
- Ameloblasts
- Odontoblasts
- Fibroblasts
At what stage does crown dentin first appear?
Pre-emergence
At what stage does the pulp chamber occur?
Pre-emergence
When is the DEJ estabilished?
Pre-emergence
What type of cells are NOT present during the pre-emergence stage
Cementoblasts
Bone ________ occurs during the pre-emergence stage
Remodeling
Fate of the Hetwig’s Epithelial Root Sheath Cells
- Diaphragm Stage
- Sheath elongation
- Root Dentin Formation
- Diaphragm stage – number or RC’s determined; tooth erupts occlusally
- Sheath elongates – determines the root dentin outline – diaphragm stays relatively at the same level
- Rooth dentin forms – sheath breaks up; cementum forms on exposed dentin…. continues apically intil th eroothdentin outline is complete
TERM – remanents of epithelial cells from Herwig’s rooth sheath in the PDL (during pre-functional stage)
They surround the tooth as part of the PDL
Epithelial Rest of Malassez
During the ____-______ stage, the merged oral epithelium and the reduced enamel epithelium undergo cell death
Pre-functional Stage
What is the most painful stage of tooth eruption and why?
Pre-functional stage (babies teething)
The inflammation and infection is responsible for this pain! Not necessarily the eruption of the teeth.
During the pre-functional stage, the merged oral epithelium and reduced enamel epithelium undergo _____ _____
This is because of lack of ____ _____ to transport nutrients
All because of the pressure the erupting teeth are putting on the overlying oral tissue
Cell Death
Blood vessels
Once the crown of the tooth has made its entry into the oral cavity, the reduced enamel epithelium now becomes —?
Junctional Epithelium
At what spot on the tooth does the juntional epithelium typically stop at during pre-functional stage
CEJ
What attaches the juntional epithelium to the tooth surface?
Basal lamina
The pre-functional stage begins with the start of ______ formation
Dentin
What “breaks up” during the pre-functional stage?
Herwig’s Epithelial Root Sheath
Differentiation of cementoblasts & cementogenesis occurs during the ____-_____ stage
pre-functional stage
How are the fibers of the PDL arranged?
Obliquely – NOT functionally arranged in groups
When does the pre-functional stage end?
When the erupting tooth reaches the occlusal plane
Functional stage:
Starts?
Ends?
Starts – at the occlusal plane
Ends – continues throughout life
During the functional stage, the main movement is ____?
This leads to anterior teeth crowding
Mesially (mesial-drift)
The attachment of the juntional epithelium chages during the ______ stage
Most likely attaching to the ________ later in life
Functional
Cementum
Functional arrangement of fiber bundles of the PDL occurs during which stage?
Functional
What are changes that can occur during functional eruption?
- Attrition
- Dead tracts
- Reparative Dentin (3*)
- Continued dentin formation (internally)
- Reduced pulp tissue volume
- Ectopic Mineralization
True or False?
A 30 year old’s mandible will be the same size as an 85 year old’s mandible
FALSE
Also …
Bone is lost when teeth are lost
Maintenance of teh Alveolar Process (remodeled bone crypt) occurs during the _______ stage
Functional
TERM – occurs between the junctional epithelium and adjacent connective tissue (lamina propria)
Reciprical Induction
What stage classifies a succedaneous tooth under a primary tooth that is in its functional stage?
Pre-emergence
What stage classification would a 6yr old’s 1st molars be in?
Pre-functional (non-succedaneous)
What stage would a 6yr old’s 2nd molar be in?
Pre-emerging
TERM – the physiologic elimination of primary teeth caused by the resorptive action of odontoclasts
Shedding
Odontoclasts originate in the ______ ____ and are conveyed to the activity site via _____ ______.
Bone Marrow
Blood Vessels
Odontoblasts resorb what 3 tooth tissues?
- Enamel
- Dentin
- Cementum
NOT PULP
In order for a permanent central incisor to ______, the ______ of the primary incisor must occur
Erupt
Shedding
You examine a palatal view of a 5yr old’s skull, what are these tiny holes?
Gubernaculum Canals
What does the gubernculum canal contain?
Gubernaculum Ligament
TERM – gubernaculum ligament passes thru the gubernaculum canal and attaches to _______ of succedaneous teeth
Dental Follicle
What are thought to help guide succedaneous teeth into the oral cavity?
Gubernaculum Ligaments
