7 - Primary Dentition Flashcards
This type of dentition is also known as “Interceptive orthodontics”
Mixed dentition
How many deciduous teeth are there?
20
How many teeth come from successional lamina?
20
Primary detention + Permanent molars =
Mixed dentition
What primary and permanent teeth make up “mixed dentition”?
Primary teeth + permanent molars
What age range do permanent teeth erupt?
6 to 13
How many permanent teeth are there?
32
What teeth are typically the last to erupt according to retrouvey for primary teeth?
Canines
Do permanent or primary dentitions have symmetrical crown shapes?
Primary
Do primary or permanent teeth have more variability?
Permanent
What are the characteristics of deciduous teeth?
- Symmetrical crown shapes
- Interdental shaping
- No angulation of incisors
- Less variability than permanent
- Arch width changes with growth
What are interdental spaces called?
Diastemas
If you have poor malocclusion in primary teeth, does the condition improve with permanent teeth?
No, it worsens
Is having interdental spacing or “diastemas” good?
Yes
Why is having interdental spacing good?
Permanent incisors require much more space
What spaces are found mesial to the upper cuspids and distal to lower cuspids in primary dentition?
Primate spaces
In what dentition are “Primate spaces” found?
Primary dentition
Where are “Primate spaces” found?
Mesial to upper cuspid
Distal to lower cuspid
What will occur if there are NO interdental spaces in the deciduous dentition?
Crowing of permanent teeth (75%)
________ between anterior primary teeth are important for permanent incisor eruption
Diastemas
How do the upper and lower incisors of primary teeth tend to erupt?
Upper incisors = labial
Lower incisors = lingual
When upper incisors erupt labial, what do they do to the arch?
Increase size
Which arch is known as the “diagnostic” arch?
mandibular
Are there increases in arch size during the eruption of permanent incisors?
No
Do eruptions of permanent incisors cause an increase in arch size?
No
Are primary teeth smaller or larger than permanent?
Anterior primary = smaller
Molars = larger
What is the largest tooth in primary dentition?
2nd primary molar
Which primary teeth are typically larger than permanent teeth?
Posterior teeth
Which primary teeth are typically smaller than permanent teeth?
Anterior teeth
What is the size of the Upper second premolar?
7mm
What is the size of the Upper second primary premolar?
8.2mm
What is the size of the Lower second premolar?
7mm
What is the size of the Lower second primary premolar?
10mm
This is an imaginary surface that passes through the occlusion of the teeth
Occlusal plane
The maxillary occlusal plane passes through what?
Occlusal cusps of posterior teeth and incisal edges of maxillary incisors
The mandibular occlusal plane passes through what?
Tangent to the occlusal cusps of posterior teeth and incisal edges of incisors
How are primary teeth positioned to the occlusal plane?
90*
Are primary or permanent teeth positioned 90 degrees to the occlusal plane?
Primary teeth
What is the curve of spee in the primary dentition?
Flat
If there is a Curve of spee present in primary teeth, what will occur?
Severe malocclusion
Dentoalverolar compensations are __________ in deciduous dentition
Not fully expressed
Why is there less variability in occlusal relationships with deciduous dentition?
Dentoalveolar compensation is not fully expressed
If a malocclusion is diagnosed in the primary dentition, it will most probably get _____ during growth
Worse
What are the occlusal relationships in deciduous dentition?
- Upper and lower incisors are vertical
- Minimal overbite and overjet
- Upper canine tip is positioned in the embrasure between the lower canine and the first primary molar
What class of occlusion do deciduous teeth typically have?
Class 1
What % of coverage does overbite have on primary teeth?
10-30%
What overjet does primary dentition have?
1-2mm
In deciduous dentition, normal occlusal changes are due to what?
Skeletal growth
In deciduous dentition, are normal occlusal changes due to dental changes?
no
What is an ectopic dental eruption?
Teeth erupt in wrong place
Can an ectopic dental eruption lead to malocclusion?
Yes
Are missing primary teeth common?
No, they are rare
Are missing permanent teeth common?
Yes
