Primary Tooth Morphology, Tooth Formation and Eruption Dates Flashcards
What are 3 other terms used for deciduous teeth?
- Primary
- Baby
- Milk
What are the 4 functions of deciduous teeth?
- Chewing (mastication)
- Support for lips and teeth
- Formulation of Speech
- Maintain arch space and room for secondary teeth
What are 2 other terms for permanent teeth?
- Secondary
2. Adult
What is the universal Identification for deciduous teeth?
A-T
How many teeth are in primary dentition?
20
What types of teeth are present in primary dentition?
Incisors, Canines, Molars
What types of teeth are not present in primary dentition?
Premolars, 3rd molars
Adult teeth #’s 4-13 replace Primary teeth _____
A-J
Adult teeth #’s 20-29 replace Primary teeth _____
K-T
The 8 Incisors in Permanent dentition have replaced what primary teeth types?
Primary Incisors
The 4 Canines in permanent dentition have replaced what primary teeth types?
Primary Canines
The 8 Premolars in permanent dentition have replaced what primary teeth types?
Primary MOLARS
What teeth types in permanent teeth are NOT considered succedaneous (non-succedaneous)?
Molars
Why are molars considered non-succedaneous?
Because molars erupt DISTAL to spaces filled with primary teeth so they are NOT succedaneous
Primary teeth crowns form between ______ months in utero
4-6
All primary teeth are erupted by age _____
2-3
All roots are completed by age ~_____
3
The eruption of primary teeth typically spans from ages ______
6 months-2 years
Only primary teeth are present from ages ______
2-6 years **usually from 3-5 all primary erupted and no permeant replacements yet
Mixed dentition is usually seen from years _______
6-12
Only permanent teeth are present from years
12+
The last permanent teeth (3rd molars) erupt from ages ______
17-21 (late teens-early 20’s)
Describe the Permanent dentition “Rule of Threes”
- Crown Formation Complete –> 3 years
- Eruption –> 3 years
- Root completion
ex. Mandibular 1st molar
- Crown complete at 3 years of age
- Eruption at 6 years of age
- Root complete at 9 years of age
Crowns of permanent teeth begin to form/calcify from ages _______
Birth –> 16 years of age
Crowns complete _____ years PRIOR to eruption
3-4+
Permanent root formation takes place during _____________
Eruption and emergence
What is the order of emergence of primary teeth (between 6 mos - 2+ years)
First: Mandibular Central Incisor (6 mos) Second: Other incisor Third: First Molars Fourth: Canines Fifth: Second molars (at about 2 years)
What is the order of emergence for all secondary teeth?
First: First molars...& mandibular central incisors Second: Other incisors Third: Mandibular Canines Fourth: Premolars Fifth: Maxillary Canines Sixth: Second molars Seventh: Late teens/Early 20's
Permanent First molars and mandibular central incisors erupt at ______ years of age
6
Permanent Other Incisors (not man. centrals) erupt at _____ years of age
7-9
Permanent Mandibular Canines erupt at ____ years of age
9-10
Permanent premolars erupt at ______ years of age
10-12
Permanent Maxillary Canines erupt at _____ years of age
12
Permanent Secondary Molars erupt at ______ years of age
12
Permanent Third molars erupt at ages ______
Late teens/Early 20s
In an 8-year old child, what adult teeth do you not expect to see?
Adult canines and premolars
In a 9-year old child, what adult teeth do you expect to see?
Adult incisors and first molars have erupted
What at 7 generalized dentition traits which are seen in primary vs. secondary teeth?
- Smaller than secondary tooth of same name
- Whiter
- Pronounced (CEJ) constriction and cervical crown bulges
- Relatively long roots compared to crowns
- Thinner enamel and dentin layers
- More wear due to bruxing
- Fewer anomalies
Are mamelons present on primary teeth?
No
What are the 4 dentition traits of ANTERIORS seen in primary vs. secondary teeth?
- Prominent lingual cingula
- No labial depressions, mamelone, or perikymata
- Anterior roots: Thin M-D
- Anterior roots bend LABIALLY in apical third
What are 5 (non-root) dentition traits of MOLARS seen in primary vs. secondary teeth?
- Prominent mesial cervical ridge (bulges) with exaggerated cervical line cure apically
- Crowns taper narrower toward occlusal with narrow occlusal table
- Wide M-D vs. occlusocervically
- Shallow occlusal anatomy: few grooves or depressions
- Second molars are larger than firsts
What are 3 Root-related dentition traits of MOLARS seen in primary vs. secondary teeth?
- Root furcations are near crown (small root trunks)
- Roots thin and slender
- Roots diverge considerably (to make room for forming adult premolars within the jaw bones
From a labial view, primary incisors are longer incisocervically than mesiodistally EXCEPT _______________
that the maxillary central incisor is wider mesiodistally
Describe the surfaces and depressions of primary incisors
Incisors have smooth surfaces, and minimal depressions
Compared to permanent teeth, primary incisors have roots relatively much ________ than crowns (before resorption)
Longer
From a lingual view, primary incisors have a cingula that is _______ & _______
Prominent and Large
In primary incisors from a lingual ivew, the marginal ridges are most prominent on ________
Maxillary central incisors (mandibular lingual anatomy is much less distinct)
From a proximal view, primary incisors are quite wide ____________ in the cervical third
Labiolingually
From a proximal view, the primary incisors have a Cervical line (CEJ) that curves greater on the _________, which is the the same shape as secondaries.
Curves greater on the mesial
In primary incisors, ALL roots bend ________ in the _______ third
bend facially in the apical third
For Maxillary (ONLY) primary incisors, the roots also bend _________ in the _____ half
bend lingually in the cervical half
T/F: From an Incisal View, The primary maxillary central incisor is much wider faciolingually than mesiodistally compared to the maxillary lateral.
FALSE! The primary maxillary central incisor is much wider mesiodistally than faciolingually compared to the maxillary lateral from an incisal view.
In primary mandibular incisors from an incisal view:
mesiodistal almost = _________
faciolingual
T/F: From a labial view, the primary maxillary incisor has a crown that is approximately as wide as it is long
TRUE : )
Like permanent mandibular canines, primary mandibular canines are longer __________
Incisocervically (vs mesiodistally)
Like permanent mandibular canines, primary mandibular canines are _______ than maxillary canines
Narrower
All primary canines have cervical lines that are __________ compared to permanent canines
Similar
The roots of primary canines taper to _______
a blunt apex
In primary maxillary canines, the mesial contact of the crown is ________
More cervical than the distal contact
**NOTE!!! THIS IS A UNIQUE TRAIT!! The only other tooth with this feature is the secondary mandibular first premolar
In primary maxillary canines, the pointed mesial cusp ridge is __________
Mesial cusp ridge is LONGER than the distal cusp ridge
***IMP! THIS IS A UNIQUE TRAIT TOO!!! The only other tooth with this characteristic is the secondary maxillary first premolar
Like permanents, the mandibular primary canines have cusp ridges which are _________
Similar (mesial cusp ridge shorter than distal cusp ridge)
From a proximal view, primary canines are thicker in the _________ than primary incisors (B-L)
Cervical third
From a proximal view, primary canines have very pronounced ____________ cervical buldges
labial and lingual cervical bulges
In which arch will you see a pronounced concave “S” shape on primary canines?
The maxillary arch has a pronounced “S” shape from a labial view
How do the cusp tips of maxillary primary canines differ from those of mandibular?
The maxillary cusp tips are positioned labial to the root axis, but mandibular primary canines have cusp tips that are positioned lingually to the root axis. (The same is true in secondaries)
From a proximal view, the primary canines have a cervical line (CEJ) that is more curved on the _______, just like secondary canines
more curved on the mesial
The roots of primary canines are bent ________ in the apical third
bent labially in the apical third
In maxillary primary canines from an occlusal view, are they wider mesiodistally or faciolingually?
Primary Maxillary canines are wider mesiodistally than faciolingually (less so on mandibular)
From an occlusal view, what is the shape of primary mandibular canines?
Diamond shape
From an occlusal view, in what direction my the cingula be offset in mandibular primary canines?
Cingula may be slightly offset to the distal
From a lingual view, Are the cingula and marginal ridges more prominent on maxillary or mandibular primary canines
More pronounced on maxillary primary canines
Like secondary maxillary canines, from a lingual view primary maxillary canines have a lingual ridge with _________
lingual ridge with mesial and distal fossae
From a lingual view, are mandibular primary canine ridges considered to be faint or prominent?
Faint ridges
How many roots do primary maxillary molars have and what are they named?
3; mesiobuccal, distobuccal, and palatal
How many roots do primary mandibular molars have and what are they named?
2; Mesial and Distal
Are primary maxillary molars wider M-D or B-L?
Maxillary are wider B-L
Are primary mandibular molars wider M-D or B-L?
Mandibular are wider M-D
Compared to the permanent premolars that will replace them, all primary molars are wider __________
mesiodistally
Where do you expect to see a bulge on primary molars?
ALL primary molars have a “buccal bulge” that is mesiobuccally located
Describe the cervical line curve of primary molars
Primary molars have cervical lines that curve apically in the mesial half of the buccal surface
Primary second molars resemble ________
Secondary 1st molars (permanent 1st molars erupt next to primary 2nd molars)
Although the primary maxillary second molars have crowns very similar to secondary maxillary 1st molars, they differ in that _________
The MB cusp is almost equal in size to the ML cusp in the primary molar, while the ML ridge is substantially larger than the MB in permanent molars
What are two identifying features of primary 2nd molars that mimics that of secondary 1st molars?
- 4 cusps plus Carabelli
2. Prominant oblique ridge
How do the cusps of the primary mandibular 2nd molar compare to those of the permanent 1st molar?
Like permanent mandibular 1st molar, primary mandibulary 2nd molars have a DB that is widest. unlike the permanent mandibular 1st molar, the primary mandibular 2nd molars have MB a D cusps that are basically the same size
In primary second mandibular molars, are the lingual or the buccal cusps shorter?
The lingual cusps are slightly shorter than the buccal
Describe the mesial marginal ridge of a primary mandibular second molar
The mesial marginal ridge is higher and crossed by a groove extending 1/3 down the mesial surface of the crown
Due to the height of the mesial marginal ridge on a primary 2nd mandibular molar, __________ can be seen from a distal proximal view
All 5 cusps can be seen
Describe the roots of primary mandibular second molars
Like the permanent teeth, the mesial root is wider than the distal
Primary 1st molars resemble what tooth?
Primary 1st molars resember NO OTHER TEETH!
***THIS IS A UNIQUE FEATURE TO KNOW FOR SURE!!
Describe the cusps of the Primary maxillary 1st molar
4 cusps, but only 2 are prominent = MB and ML…the DB and DL cusps are very very small.
Also, MB cusp is the longest, and the ML cusp is the sharpest
Like in permanent dentition, the DL cusp of a primary maxillary 1st molar ________
can be absent
In primary maxillary 1st molar, are the crowns wider F-L or M-D?
Slightly wider F-L
Are primary maxillary 1st molars (buccal view) wider M-D or higher O-C?
Wider M-D ( like secondary molars)
Describe the pattern of the occlusal grooves in a primary maxillary 1st molar
H-pattern
Describe the cusps of the Primary Mandibular 1st molar
4 cusps (MB, DB, ML, DL); MB is largest and longest cusp; compared to the DL cusp, the ML cusp is larger and sharper
From a facial view, are primary mandibular 1st molars wider M-B or higher O-C?
Wider M-D
The primary mandibular 1st molar has a 3 very prominent ridges :____________
- MB cervical ridge or bulge
- Mesial transverse ridge
- Mesial marginal ridge
Describe the lingual tilt of a primary mandibular 1st molar (and why so?)
Accentuated lingual crown tilt due to prominent MB cervical ridge
Compare the pulp cavities of primary teeth to secondary teeth
Pulps are relatively larger in proportion to the tooth size in primary teeth
Where are the molar pulp chambers in primary molars located (and why)?
Molar pulp chambers are located mostly in the crown (due to short root trunk)
Describe the pulp horns of primary teeth
Primary teeth have narrow pulp horns that are located beneath the cusps
Why is it especially important to understand the relative size of the pulp chambers in primary teeth?
Because the large pulp size makes it easier to expose during tooth preparation
What is the relative sequence eruption of primary teeth?
- Centrals
- Laterals
- 1st molars
- Canines
- 2nd molars
* *mandibular teeth usually precede maxillary but not always
How do you determine age and teeth present in the mouth by clinical exam (6 years or not?)?
Count from the central incisor back….if you count 5, there is no 6 year old molar so the child is less than 6 years old.
What is the eruption time of the primary mandibular central incisor?
6 months
What is the eruption time of the primary mandibular lateral incisor?
9 months
What is the eruption time of the primary mandibular 1st molar?
12 months
What is the eruption time of the primary mandibular canine?
16 months
What is the eruption time of the primary mandibular 2nd molar?
20 months
Give a full run-down of the eruption times for each primary tooth in the mandibular arch
Central Incisor: 6 mos Lateral Incisor: 9 mos 1st Molar: 12 mos Canine: 16 mos 2nd molar: 20 mos
What is the eruption time of the primary maxillary central incisor?
7 mos
What is the eruption time of the primary maxillary lateral incisor?
7 mos
What is the eruption time of the primary maxillary first molar?
14 mos
What is the eruption time of the primary maxillary canine?
18 mos
What is the eruption time of the primary maxillary 2nd molar?
24 mos-3 yrs
Give a full run-down of the eruption time for each tooth in the primary maxillary arch
Central incisor= 7 mos Lateral incisor= 7 mos 1st molar=14 mos Canine=18 mos 2nd molar= 24 mos-3 yrs
Compare the eruption sequence of all 4 primary incisors
First the mandibular central incisor erupts at 6 mos, then the central and lateral maxillary incisors erupt at 7 mos, and lastly, the lateral mandibular incisor erupts at 9 months
In what way do primary incisors break the “rule” of mandibular teeth erupting before maxillary?
The primary maxillary lateral incisor erupts at 7 months, which is BEFORE the mandibular lateral erupts at 9 mos
What is a tooth called that a child is born with?
Natal tooth
About _______ months either way does not mean a child in abnormal in the eruption pattern
~3-4 mos
Which teeth are succedaneous teeth?
The 20 teeth that replace the 20 primary teeth: 4-13 and 20-29
What are the 3 “kinds” of teeth found in a mixed dentition mouth?
- Permanent but non-succedaneous
- Permanent and succedaneous
- Deciduous
What is the 1st primary tooth to erupt in the mouth?
Mandibular central incisor
What do the 4th and 5th types teeth to erupt in the primary dentition have in common?
Both the 4th and 5th teeth to erupt are in the mandibular arch (lateral incisor at 9 mos, and 1st molar at 12 mos)
**note that this breaks the pattern of a mandibular erupting, followed by a maxillary…and back and forth
What is the last primary tooth to erupt in the mouth?
Maxillary 2nd molar
What two primary teeth erupt in the mouth at the same time?
Maxillary central and lateral incisors
What is the eruption time of the permanent mandibular 1st molar?
6-7 years
What is the eruption time of the permanent maxillary 1st molar?
6-7 years
What is another name for the permanent 1st molars?
“6-year molars”
What is the eruption time of the permanent mandibular central incisor?
6-7 years
What is the eruption time of the permanent maxillary central incisor?
7-8 years
What is the eruption time of the permanent mandibular lateral incisor?
7-8 years
What is the eruption time of the permanent maxillary lateral incisors?
8-9 years
What is the eruption time of the permanent mandibular canines?
9-10 years
What is the eruption time of the permanent maxillary canines?
11-12 years
What is the eruption time of the permanent mandibular 1st premolar?
10-12 years
What is the eruption time of the permanent maxillary 1st premolar?
10-11 years
What is the eruption time of the permanent mandibular 2nd premolar?
10-12 years
What is the eruption time of the permanent maxillary 2nd premolar?
11-12 years
What is the eruption time of the permanent mandibular 2nd molar?
11-13 years
What is the eruption time of the permanent maxillary 2nd molar?
12-15 years
What is the sequence of eruption of permanent mandibular teeth?
- 1st molar
- Central Incisor
- Lateral Incisor
- Canine
- 1st premolar
- 2nd premolar
- 2nd molar
- 3rd molar
What is the sequence of eruption of permanent maxillary teeth?
- 1st molar
- Central incisor
- Lateral incisor
- 1st premolar
- 2nd premolar
- Canine
- 2nd molar
- 3rd molar
As far as types of teeth erupting, how does the sequence of eruption in maxillary permanent teeth vary from mandibular
In mandibular teeth, the eruption sequence is 1st molar then in order from #24/25 back, but in the maxillary arch, again, the 1st molar comes first and the #8//9 back EXCEPT for the fact that the canine does not erupt after the lateral incisor, but rather after the 2nd premolar
At 10 years of age, what teeth permanent teeth would you NOT expect to see in the mouth
Would not see permanent 2nd or 3rd molars, or mandibular 2nd premolar, or maxillary canine
What permanent teeth do you expect to see in 6-9 year olds?
1st molars and all incisors
At 9-10 years of age, what permanent teeth should be erupting?
Mandibular Canines (know this one for sure!!)
What permanent teeth are (surprisingly) often the last to erupt?
Maxillary Canines
What permanent teeth should you expect to be erupting/ have just erupted at ages 10-12?
Maxillary and Mandibular premolars
12 year molars
Maxillary canines
What is the full sequence of eruption of primary teeth?
1. Mandibular Central 2/3. Maxillary Central 2/3. Maxillary Lateral 4. Mandibular Lateral 5. Mandibular 1st molar 6. Maxillary 1st molar 7. Mandibular Canine 8. Maxillary Canine 9. Mandibular 2nd molar 10. Maxillary 2nd molar
What is the full sequence of eruption of permanent teeth? (Approx…lots of overlap…so, just about)
1/2. Mandibular 1st Molar 1/2. Maxillary 1st Molar 3. Mandibular Central Incisors 4/5. Maxillary Central Incisor 4/5. Mandibular Lateral Incisors 6. Maxillary Lateral Incisors 7. Mandibular Canines 8. Maxillary 1st premolars 9/10. Mandibular 1st premolar 9/10. Maxillary 2nd premolar 11/12. Mandibular 2nd premolar 11/12. Maxillary Canines 13. Mandibular 2nd molars 14. Maxillary 1st molars