8 - Mixed Dentition Flashcards
What term is used for when permanent incisors are larger than primary incisors the replace?
Incisor liability
Upper permanent incisors erupt ____ to primary teeth
Labial
Lower permanent incisors erupt ____ to primary teeth
Lingual
Do you gain or lose size in the mandible when permanent teeth erupt?
Lose size
What are the different dental arch measurements?
Arch length
Arch width
Arch perimeter
Intercanine distance
This is measured at the midline to a tangent touching the distal surface of the 2nd primary molars
Arch length
When is the arch length stable?
Once primary incisors erupt
How do you get growth in arch length?
Displacement in space
How is dental arch width/intercanine distance measured?
- Between cusps of canines in the transverse plane
- Between occlusal grooves of the 2nd primary molars
- Between occlusal grooves of the permanent 1st molars
You get no change of intercanine distance after what age?
10-11
How much distance is gained in the arches and intercanine distance from 4-10 years?
4mm
This is measured from the distal surface of the 2nd primary molar around the arch over the contact points and incisal edges in a smoothed curve
Arch perimeter
What is used as a “baseline” of the arch before treatment?
Dental arch perimeter
Does elongation of the roots have something to do with tooth eruption?
No
What age range do you get mixed dentition?
6-13 years
What is the 1st permanent tooth to erupt that is “non-succedaneous”?
1st molar
Describe primary root resorption
- Crown of permanent tooth is formed
- Root develops and primary tooth starts to resorb
- When root is fully resorb, permanent tooth erupts
Does permanent tooth eruption of primary root resorption occur 1st?
Resorption
When does a permanent tooth erupt?
When primary root has fully resorbed and exfoliated
When will the permanent tooth stop erupting?
When it reaches the occlusal plane
At what age would be the best to take a panorex?
Around 8
What is the variability in tooth replacement?
Sequence
Timing
Position
Numbers
In what percentage of the population are their congenitally missing teeth?
3-5%
What is the most frequently missing tooth in caucasians?
Maxillary lateral incisor
What are the most frequently missing teeth in the Asian population?
Lower central incisor (1)
Lower lateral incisor (2)
What 2 things can a missing primary tooth mean?
- No permanent successor
- Delayed eruption
This 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 becomes more evident in
Mixed dentition
What is the treatment for ankylosis?
Monitor teeth as they 50% self-forrect
If it doesn’t exfoliate, extract
