This lesson aims to simplify eruption dates and make them easier to learn. You should then be comfortable in applying these to your paediatric patients and explain to them what stage of dental development they are in.
Remember that these ranges are generl guidance, but in reality, eruption dates can vary from patient to patient.
See 'Application as a GDP' tab for spotting the potential warning signs of abnormal eruption, eg. 6 month+ discrepancy in symmetry of eruption.
Primary Dentition:
The general patterns of eruption are (1):
A-B-D-C-E
Maxillary before Manidbular (with the exclusion of As)
Root formation is complete 12-18 months post-eruption.
-
-
A
A
MD As: 6-10 months
A
A
-
-
MX As: 8-12 months
B
B
-
-
MX Bs: 9-13 months
-
-
B
B
MD Bs: 10-16 months
D
D
-
-
MX Ds: 12-18 months
-
-
D
D
MD Ds: 14-18 months
C
C
-
-
MX Cs: 16-22 months
-
-
C
C
MD Cs: 16-24 months
E
E
-
-
MX Es: 22-33 months
-
-
E
E
MD Es: 24-31 months
Permanent Dentition:
Generally, the pattern of eruption is: 6 1 2 3 4 5 7 8.
Remember that at the ages of 9-10 years, no eruption occurs, and developmental changes are only visible radiographically.
Crown completion occurs 3-5 years before eruption.
6s calcify 32 weeks in utero
Root formation is complete 2-3 years post-eruption.
6 years:
Commonly parents and child will present complaining of 'gappy teeth'. Explain to the parents that this is normal and should close once all permanent teeth come through (provided it is purely down to eruption causes, and not soft tissue causes such as frenal attachments).
6
6
6
6
Teeth Erupting at Age 6 years
-
-
1
1
Teeth Erupting at Age 6 years
7 years:
1
1
-
-
Teeth Erupting at Age 7 years
-
-
2
2
Teeth Erupting at Age 7 years
8 years:
The diastema, if present, usually closes around this age.
2
2
-
-
Teeth Erupting at Age 8 years
9 years:
1/3 root of the mandibular 3s and 4s are visible
10 years:
½ root of the mandibular 3s and 4s now visible
Root completion of maxillary 1s and 2s
11 years:
-
-
3
3
Teeth Erupting at Age 11 years
4
4
4
4
Teeth Erupting at Age 11 years
12 years:
Formation of 8s may be visible on an OPG now
3
3
-
-
Teeth Erupting at Age 12 years
5
5
5
5
Teeth Erupting at Age 12 years
13-15 years:
8s more apparent on OPG by now.
7
7
7
7
Teeth Erupting at 13-15 years
18-21 years:
8
8
8
8
Teeth Erupting at Age 18-21 years
Clinical Considerations:
At 9 years:
Expect increase in inter-canine width
Incisors lie lingual to Manibular As, but will erupt labially
This can lead to crowding, meaning the laterals begin to erupt lingually.
6s
If there is crowding present, the 6s may impact into Es
Normally erupt into ½ unit class II – cusp to cusp. The lower molar then drifts to form a Class I molar relationship (ideally).
Handy tips to remember tooth eruption dates:
Paediatric: N.I.U
Note: these eruption ranges may differ to the ones above to aid simplicity in remembering them. If you can remember these dates with a +/- few months rule, this should suffice:
Primary Teeth Eruption Dates - in months
Permanent: 2 Ls (purple and orange), and everything in-between!
Permanent Teeth Eruption Dates
OPG
Why not try to write a report on this mixed dentition OPG and guess the patient's age?
Remember to follow a logical order.
Eg. Start in the Upper Right Quadrant and count the teeth present in each quadrant. Once you have the full picture of the teeth present, you will be able to take a good estimate of the patient's dental age.
OPG of Mixed Dentition
Conclusion
We hope this lesson has made learning eruption dates easier and more enjoyable. This lesson could prove useful on your clinics, so maybe have it open ready as a quick reference guide.
