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How Does Shedding Occur?
¾The permanent teeth exert pressure against
Deciduous Teeth
p gthe deciduous rootscausing their resorption Anterior Teeth
¾ Shedding (root resorption)takes about 3-4 years
Posterior Teeth
Retained Deciduous tooth
Differences Between id & i iDeciduous & Permanent Dentition
¾ Anatomical
¾Histological ¾Histological
Differences Between Deciduous & Permanent Dentition
1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
1. Number1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
20 Deciduous TeethPredecessors
Permanent Teeth32 successors
Non-successors20
12
2
¾ The crowns are smaller
2. Size1. Number2. Size3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
¾ The roots are shorter
¾Whiter in color
3. Color1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Morphologic Differences
¾ Less whiter
Deciduous Teeth
Permanent Teeth
¾ Shorter time for crown development
4. Development of Teeth
1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
p( Deciduous incisor 4 M.I.U 4 M.)
( Permanent incisor 4 M. 4-5 Y.)
¾ Shorter time for complete
Crown completed
Evidence of calcification
Deciduous Dentition
4 M4 M.I.U. Central incisors
5¾ Shorter time for completeroot formation
( Deciduous incisor (1-1.5 Y.) ( Permanent incisor ( 2-3 Y.)
5 M4.5 M.I.U
Lateral incisors
9 M5 M.I.U Canines
6 M5 M.I.U. First molars
10-12 M6 M.I.U Second molars
9 Prenatal systemic disturbancesAffect calcification of primary teeth
5. Calcification
1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
9 Postnatal systemic disturbances
Affect calcification of primary teeth
yAffect calcification of permanent teeth
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from the pressureDue to permanent successors
1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
6. Root Resorption
7. Hardness
Less harder than permanent teeth
8. Morphologic Differences
Anterior Teeth
1. Number2. Size 3. Color4. Development5. Calcification6. Root Resorption7. Hardness8. Morphologic Differences
a. Wider mesiodistally in comparison to their length
b. Prominent cervical ridge
Crowns
a. Narrowb. Labial inclination (upright position)c. Twice length of crown ( C1: R 2 )
Roots
Posterior TeethDeciduous Teeth
a. Prominent buccal ridgeb. Constricted tooth neckc. Narrower occlusal surface buccolingually
Crowns
a. Slender, long & flatb. Flarying out apicallyc. Very short trunks or absent
Roots
lEnamel
• Enamel• Dentin
• Pulp
Histological Differences betweenDeciduous and Permanent Teeth
Deciduous Molar
Enamel
DentinThin
Dentinlimited thickness and less hardness
Enamel-dentin junctionRelatively smooth
Enamel
Dentin
Permanent Molar
4
Large size of the pulp and prominent pulp horns
Permanent Molar
Deciduous Molar
Deciduous Teeth
Morphology of TeethMorphology of TeethMorphology of TeethMorphology of Teeth
M h ll i i
It resembles the permanent maxillary central incisor EXPECT:
DeciduousMaxillary Central Incisor
¾ Much smaller in size
¾ The crown mesiodistally is greater than cervicoincisally
¾ The labial surface is smooth without developmental lineswithout developmental lines
¾ The lingual surface shows less developed marginal ridge and cingulum
It resembles the permanent maxillary lateral incisor EXCEPT:
Deciduous Maxillary Iateral Incisor
Deciduous Teeth
¾ Smaller than permanent lateral
¾ The crown length cervicoincisally is greater than its mesiodistal width
¾ The distoincisal angle is more rounded
5
Deciduous Maxillary Canine
It is similar to the permanent maxillary canine EXCEPT:
Deciduous Teeth
¾ Smaller in size
¾ More constricted at the cervix
¾ MCA & DCA at the center of the middle thirdmiddle third
¾ Longer and sharper cusp
¾ Root length twice crown length
Deciduous Mandibular Canine
It is similar to the permanent:EXCEPTmandibular canine
Deciduous Teeth
¾ Smaller in size
¾ More pointed cusp tip
¾ Developmental depression along the labial surface of the root
Deciduous MaxillaryFirst & Second molar
Deciduous Teeth
¾ It is much wider PR
¾ Four cusps and three roots
Deciduous Maxillary First Molar
mesiodistally at the contact areas than at the cervix
¾ The occlusal line is scalloped with no definite cusp
MBRDBR
PR
¾ The buccal surface is smooth
¾ The roots are long and slender with short root trunk Buccal Aspect
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¾ The crown converges in a lingual direction
DeciduousMaxillary First molar
DBR¾MLC is the longest and sharpest of all cusps¾DLC cusp is poorly develop and sometimes absent
¾ All three roots are seen from
PR
MBR
DBR
¾ All three roots are seen from this aspect and the palatal root is larger than the others
MLC DLC
Lingual Aspect
¾ Prominent cervical ridge
h d
DeciduousMaxillary First molar
¾The crown is wider buccolingually at the cervical ridge than at the occlusal third
MBR LR
¾The LR appears slender and extends lingually to a marked degree Mesial Aspect
¾ Rectangular with shortest sides represented by the marginal ridges
¾ Four cusps and two fosse; central and mesial triangular
DeciduousMaxillary First molar
¾ Oblique ridge connecting the MLC with DBC
¾ Central developmental groove¾ Buccal developmental groove
Th d l t l MLC
DBCMBC
DLC
¾Three developmental grooves radiating from the mesial triangle fossa; one buccally, one lingually and one toward the marginal ridge
Occlusal Aspect
Occlusal Aspect
MBCBDG
DBC
MBC
CDG
MTFCF
BDG
MLCDLC
7
¾ Five cusps and three rootsMBR
DBR
DR
¾ It is similar to the permanentmaxillary first molar EXCEPT:
Deciduous Maxillary Second Molar
¾The crown is more constricted at the cervix
¾ Prominent cervical ridge
¾ The rootsDBC MBC
maxillary first molar EXCEPT:
¾ Root Trunk is short and sometimes absent
More slender and twice the length of the crown and greatly flare out
MLCDLC
V
d d b lDeciduous Mandibular First molar & Second molar
¾ Mesial outline is straight
¾ Four cusps and two roots
Deciduous Mandibular First Molar
¾ Cervical line dipping apically where it joins with the mesial root
DCA
¾ Distal outline is marked convex making the DCA extends distally to a great degree
Mesial
¾ Roots long, slender and flaring greatly
¾ Short root trunk
Buccal Aspect
MRDR
¾The crown and root
DeciduousMandibular First MolarLingual Aspect
converge lingually MLC DLC
¾ MLC is long & sharp¾ DLC is rounded and well develop
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¾ The crown is roughly h b id l
MBCMLC
DeciduousMandibular First MolarMesial Aspect
rhomboidal
¾ Prominent cervical ridge
¾ MBC & MLC connected by developed MMR
MR
by developed MMR
¾ Mesial rootParallel outlines with long developmental depression along the full length of the root
Mesial Aspect
MBCMLC
DeciduousMandibular First Molar
The prominent cervical ridge is observed from this aspect
Occlusal AspectDeciduous
Mandibular First Molar
¾ Four cusps , MLC is the largest cusp
¾ Central fossa and mesial
CR
¾ Central fossa and mesial triangle fossa with CDG extends between them
¾ It has five cusps and two roots¾ It is similar to the permanent
Deciduous Mandibular Second Molar
¾ Smaller in size
¾ MBC, DBC, DC are almost equal in size
MB DBDC
p:EXCEPTmandibular first molar
¾ The roots are more slender, flaring out
¾ Short root trunk
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DBC MBCDC
Occlusal AspectDeciduous
Mandibular second molar
CF
CDG
MBTRDBTR
MLTRDLTR
DTR
MTFDTF
MLCDLC
MLTR
3 years oldOcclusal Dental formula
A B C D EA B C D E
A B B C C D D E EA M1/3 D 2/3 MS DS M 1/3 D 2/3 1/5 4/5
Deciduous Teeth
Occlusion of Deciduous Teeth
Occlusal Dental formula
A M1/3
D2/3 MSDS M1/3
D2/3 1/5 4/5
5 years old
Deciduous Teeth
Occlusion of Deciduous Teeth