Oral Anatomy Final - Primary Dentition Flashcards
questions taken from lecture powerpoints
What are the functions of primary (deciduous) teeth?
- chewing (mastication)
- support for lips and cheeks
- formulation of speech
- maintain arch space and room for secondary teeth
What tooth type is present in secondary dentition, but not present in primary dentition?
premolars
What range of adult teeth (in universal numbers) replace maxillary primary teeth A-J?
4-13
What range of adult teeth (in universal numbers) replace mandibular primary teeth K-T?
20-29
What is the definition of succedaneous teeth? Of non-succedaneous teeth? Give an example of a non-succedaneous tooth.
Succedaneous teeth replace primary teeth.
Non-succedaneous teeth do NOT replace primary teeth because they erupt distally to the primary teeth. All of the secondary molars are examples of non-succedaneous teeth.
When do primary teeth crowns form?
4-6 months in utero
At what age are all primary teeth erupted?
age 2-3
At what age are all primary roots completed?
approximately age 3
Between birth and 6 months, what teeth are erupted in the mouth?
none
Between 6 months and 2 years old, what teeth (in general) are erupting in the mouth?
primary teeth are erupting
From 2 to 5/6 years old, what teeth (in general) are erupted in the mouth?
only primary teeth present
Explain the “Rule of Three” for permanent dentition.
Hard tissue formation begins. After 3 years, crown formation is complete. After 3 more years, the tooth erupts. After another 3 years, the root formation is complete.
For PRIMARY teeth, at what age are crowns completely formed?
6 months (10-12 months after formation begins)
For PRIMARY teeth, at what age are roots completely formed?
1.5 to 3 years after emergence of the tooth
For PERMANENT teeth, between what ages are crowns forming/calcifying?
from birth to 16 years old
How many years prior to eruption are permanent crowns completed?
3-4 years prior to eruption
How many years after eruption are permanent roots completed?
3 years after eruption
What is the order of emergence of the primary teeth?
- mandibular central incisors (6 months old)
- other incisors
- first molars
- canines
- second molars (2 years old)
At what age do the secondary first molars erupt?
6 years old
At what age do the secondary mandibular central incisors erupt?
6 years old
Between what ages do the secondary incisors (not including mandibular central incisors) erupt?
7-9 years old
Between what ages do the secondary mandibular canines erupt?
9-10 years old
Between what ages do the secondary premolars erupt?
10-12 years old
At what age do the secondary maxillary canines erupt?
12 years old
At what age do the secondary second molars erupt?
12 years old
When do the secondary third molars typically erupt?
late teens or early 20s
In GENERAL, what arch tends to erupt first with secondary dentition?
usually mandibular arch erupts before maxillary
Which teeth (primary or secondary) are generally whiter in color?
primary teeth
True or false: Primary teeth have relatively long roots compared to crowns.
true
Which teeth (primary or secondary) generally have thinner enamel and dentin layers (easier access to pulp)?
primary teeth
In which direction do primary anterior teeth roots bend?
Primary anterior roots bend labially in the apical third to allow permanent teeth to have proper alignment.
Is the primary maxillary central incisor wider incisocervically or mesiodistally?
The primary maxillary central incisor is wider mesiodistally.
*NOTE: this is different than permanent dentition
On which primary incisors are marginal ridges most prominent?
maxillary central incisors; mandibular lingual anatomy is less distinct
On which side (mesial or distal) is the curve of the CEJ greater for primary teeth?
mesial (like permanent dentition)
Which proximal contact is more cervical in primary maxillary canines?
mesial contact is more cervical
*NOTE: this is only true for primary maxillary canines and permanent mandibular first premolar
Which cusp ridge is longer in primary maxillary canines?
mesial cusp ridge is longer
*NOTE: this is only true for primary maxillary canines and permanent maxillary first premolar
On which arch do the primary canines have marginal ridges and lingual ridges more prominent?
maxillary arch (like secondary dentition)
True or false: The crown tapers toward the cervical in primary molars.
FALSE. The crowns taper narrower toward the occlusal with a narrow occlusal table.
*NOTE: this is different than permanent teeth
For primary dentition, which are larger: first or second molars?
second molars are larger than first
*NOTE: this is different than permanent teeth
What bulge is prominent on primary molars?
mesiobuccal bulge
For a primary mandibular second molar, what buccal cusp is the widest?
distobuccal cusp is the widest; mesiobuccal and distal cusps are almost the same
*NOTE: this is different than the permanent mandibular first molar in which the mesiobuccal cusp is the largest and distal cusp is the smallest
What permanent teeth do primary second molars resemble?
permanent first molars
What permanent teeth do primary first molars resemble?
none (maxillary molars sometimes look similar to a premolar, but still not truly resembling)
What two cusps are prominent in primary maxillary first molars?
mesiobuccal and mesiolingual cusps
How many cusps are present in primary mandibular first molars? Which cusp is the largest and longest?
4; mesiobuccal cusp is the largest and longest
What is the shape of the groove pattern of primary maxillary first molar?
“H” pattern
Between what ages does the secondary mandibular first molar erupt?
6-7 years old
Between what ages does the secondary mandibular central incisors erupt?
6-7 years old
Between what ages does the secondary mandibular lateral incisors erupt?
7-8 years old
Between what ages does the secondary mandibular canines erupt?
9-10 years old
Between what ages does the secondary mandibular first premolar erupt?
10-12 years old
Between what ages does the secondary mandibular second premolar erupt?
11-12 years old
Between what ages does the secondary mandibular second molar erupt?
11-13 years old
Between what ages does the secondary maxillary first molar erupt?
6-7 years old
Between what ages does the secondary maxillary central incisor erupt?
7-8 years old
Between what ages does the secondary maxillary lateral incisors erupt?
8-9 years old
Between what ages does the secondary maxillary first premolar erupt?
10-11 years old
Between what ages does the secondary maxillary second premolar erupt?
10-12 years old
Between what ages does the secondary maxillary canines erupt?
11-12 years old
Between what ages does the secondary maxillary second molars erupt?
12-15 years old
Give an example of isomorphism.
The primary second molars look like the secondary first molars.
