Mixed Dentition- FINAL- Retrouvey Flashcards
The difference in sizes of the primary anterior incisors and the permanent anterior incisors=
incisor liability
Lower permanent incisors erupt ___ to the primary
How does the effect the arch?
lingually
arch size decreases
Upper permanent incisors erupt ___ to the primary incisors.
How does this effect the arch?
labially/facially
Arch size increases
Dental arch measurement include:
- arch length
- arch width
- arch perimeter
- inter canine distance
Measured at the midline to a tangent touching the distal surfaces of the second primary molars
arch length (depth)
Arch length is measured at the midline to a tangent touch the ___ surfaces of the ____
distal surfaces; second primary molars
The arch length is stable once the:
permanent incisors are in
If one sees “growth” of the arch length after the primary incisors are in, this is due to _____ and actually growth.
displacement in space
Arch length changes include:
- lose arch length in the lower arch (due to lower incisor eruption)
- gain arch length in the upper arch (due to upper incisor eruption)
Measured between the cusps of the canines tips in the transverse plane
arch width
Measured between the occlusal grooves of the second primary molars
arch width
arch widths are give in ___ measurements
2 different measurements (which allows you to estimate the transverse development of the arches)
Although “there are no significant changes from primary to mixed dentition in the lower arch width”, there is about 4mm of changes between ages:
4-12 years old
Intercanine distance increases until age ____ in girls and ___ in boys
10-11 in girls; 11-12 in boys
(+3-4 mm roughly)
Measured from the distal surface of the second primary molar around th arch over the contact points and incisal edges in a smoothed curve:
arch perimeter
Arch perimeter before treatment is referred to as:
baseline (T0)
The elongation of the roots has nothing to do with:
tooth eruption
(rather the crown is pulling the root)
From __ to __ years old, the primary dentition is replaced by the permanent dentition resulting in mixed dentition
6-13
The permanent first molars erupt to the ____ of the primary dentition (no primary tooth replacement)
distal
1st, 2nd, and 3rd molars do not:
replace primary dentition (erupt distal to primary dentition)
Primary root resorption is a result of
permanent tooth eruption
Permanent tooth eruption causes:
primary root resorption
Put the following events in order:
A) primary tooth starts to resorb
B) permanent root develops
C) crown of permanent tooth is formed
- Crown of permanent tooth is formed
- Permanent root develops
- Crown of permanent tooth is formed
When does the primary tooth exfoliate and the permanent tooth erupt?
When the primary root is totally resorbed
What happens when the primary root is totally resorbed?
the primary tooth exfoliates and the permanent tooth erupts
When does the permanent tooth stop erupting?
when it reaches the occlusal plane or contacts an opposing tooth
What gives the power to cause the primary root to resorb/baby tooth to fall out?
permanent tooth eruption
What do we mean by “root development is not a main factor in eruption”
The root forms at the same time that the tooth erupts (IT DOES NOT PUSH THE CROWN UP)
You shouldn’t do a panoramic x-ray before the age of:
8
For eruption of permanent dentition, there are variable patterns between:
3-4-5
(canine, premolar 1, premolar 2)
The tooth replacement sequence is variable in terms of:
- sequence
- timing
- position
- numbers
- shape
What are tooth eruption patterns for teeth 3,4,5?
- 3,4,5
- 4,3,5
- 4,5,3
At 13 years old, describe what dentition should look like:
most permanent teeth should be in
The root of the permanent tooth has to be ___ formed PRIOR to extraction of primary tooth
2/3 formed
variability in tooth numbers can be a result of:
ethnicity
Congenitally missing teeth are rare affecting ___ % of the population
3-5%
What is the most frequently congenitally missing tooth? (in Caucasian population)
lateral incisor
What are 2 common congenitally missing teeth?
- maxillary lateral incisor (most frequent)
- mandibular 2nd premolar
A missing primary tooth = ____ meaning ___
no permanent successor = delayed eruption
A missing primary tooth = ____ meaning ___
___ effects growth of the alveolar processes
ankylosis
Refers to the fusion of part of the root of a primary tooth to the underlying bone, which stops the tooth from erupting:
ankylosis
Ankylosis may be due to localized defect during eruption process in the ____ whereby ___.
PDL; osseous
Ankylosis becomes more prevalent in mixed dentition where occlusal level of ankylosed tooth:
does NOT keep up with the vertical level of the adjacent teeth
What is responsible for keeping the teeth in contact during growth and may a role in ankylosis?
dentoalveolar development
Treatment of ankylosis usually involves:
simply monitor these teeth (50% self correction)
If an ankylosed tooth fails to correct itself/ fails to exfoliate, it may advisable to:
extract the tooth to avoid damages to the permanent dentition
When the tooth growing is in the complete wrong position:
ectopic eruption
The most common tooth for ectopic eruption:
mandibular canine
