Date post: | 03-Jun-2015 |
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Condition of Teeth Condition of Teeth At Different AgesAt Different Ages
1- Teeth begin its calcification long before its date of eruption.
2- When tooth erupts the crown and about 1
3
of the root is completed.
3- Roots are completed after eruption by 1-1.5 years (for deciduous) and after eruption by 3 years (for permanent).
4- Roots of deciduous teeth begin resorption 3 years before shedding.
Generally:
Chronology Of Deciduous
Teeth
• Enamel organ for deciduous teeth appears from 7-9 w.i.u.
• Beginning of calcification of deciduous from 4-6 m.i.u.
• Deciduous Canines erupt after deciduous1st molars.
• Mandibular teeth erupt before maxillary teeth.
• Shedding occurs at the same date of eruption of successors.
• Shedding of deciduous teeth occurs from 7-11 years
For deciduous teeth:
A B C D E A B C D E
1 2 4 3 5
Lower before upper
Beg. Of Beg. Of calc. calc. (m.i.u)(m.i.u)
EruptionEruption(m.)(m.)
Root Root completed completed (Y)(Y)
BeginningBeginning
of root res.of root res.
AA
AA
BB
BB
CC
CC
DD
DD
EE
EE
454.5
6
76
78
24
1412
1618
20
1.5
3
2.5
3
-3 ye
ars
befo
re s
hedd
ing
Chronology Of permanent
Teeth
For permanent For permanent teeth:teeth:
*At birth, first permanent molar is the only permanent tooth showing evidence of calcification .
*Dates of eruption of permanent incisors is the same as deciduous incisors but in years.
*Premolars start calcification between 112 & 2
12 y .
*Lower teeth sequence of eruption is 1 2 3 4 5. *Upper teeth sequence of eruption is 1 2 3 5.
*Lower teeth erupts before upper opposing teeth. *First, second& third molars erupt at ages of 6,12,18
years respectively .
4
Beginning Beginning of calcof calc..
))monthmonth((
Crown Crown completedcompleted
EruptionEruption
(years)(years)
Root Root completedcompleted
11
11
22
22
33
33
3-4
73-4 -3
year
s
7
94-5
10-12
+3 ye
ars
11
8
6
Beginning Beginning of calcof calc..
Crown Crown completedcompleted
EruptionEruption
(years)(years)
Root Root completedcompleted
44
44
55
55
134
2
10
11-12
10
11-12
112 -
3-4
ye
ars
+3 ye
ars
212
Beginning Beginning of calcof calc..
Crown Crown completedcompleted
EruptionEruption
(years)(years)
Root Root completedcompleted
66
66
77
77
88
88
3y
6y
12y
At birth -
3-4
ye
ars
+3 ye
ars
8y 18y
• Permanent teeth ML cusp of lower 6. • No erupting teeth
½ crown
Less than1/2
Cusp tip
Occ.S Separate
cusp
ML cusp
6 months
start eruption
Crown&1/4 root
most of crowns formed C&D&E
Incisal 1/3 of 1&2
separate cusps of 6
cusp tip
1 year
AB
CDE6
13
2
2 years
ABCDE
6
13 245
3 years
All deciduous teeth erupted with fully formed teeth
More than ½ crown of 1&2 formed
½crown 3
small part of 4&5
crown of 6 completed
separate cusps of 7
Root of lower A resorped
B&C&D some amount of resorption
E no resorption
crown&1/3 root formed
less than 1/3 of the root formed
crowns of 3&4&5 formed
6 is erupted
crown of 7 not completed
7 years
7-8 years
7 years
BCDE
6
1
3
2
45
7
C&D&E most of their roots
resorbed
1&2 is erupted their root completed
3&4&5 not yet erupted &less than 1/3 of root formed
root of 6 completed
7 crown& less than 1/3 root formed
8 Calcified separate cusps are formed
All permanent teeth erupted except 8 .