2. content
• Predentate Period
• Deciduous Dentition Period
• Mixed Dentition Period
• Permanent Dentition
• Self-correcting Anomalies
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3. PREDENTATE PERIOD,
Gum pads stage (0-6 months).
The alveolar process at the time of birth is called the gum pads
They are horseshoe shaped pads that are pink, firm and covered with a layer of dense periosteum
The gum pad is further divided into 10 segments by transverse groove; each segment has one
developing tooth sac.
Lateral sulcus
infantile open bite
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5. DECIDUOUS DENTITION PERIOD
The initiation of primary teeth occurs during first six weeks of intrauterine life and
the first primary tooth erupts at the age of 6 months.
it takes around 2½ to 3½ years for all the primary teeth to establish their
occlusion.
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6. Characteristics features of Deciduous Dentition
1. Spacing: delabare 1918, baume 1950, Hamilton 1969
Spaced dentition: It is supposed to be good,
1. Primate spaces: Exist between the maxillary lateral incisors and the canines (present mesial to
maxillary deciduous canines) and mandibular canines and 1st deciduous molars (present distal to
mandibular deciduous canines).
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7. Spacing
2. Physiologic spaces:
may vary from 0 to 8 mm with the average 4 mm at maxillary
and 1 to 7 mm with the average of 3 mm in the mandibular arch.
Closed dentition/ Nonspaced dentition
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8. 2. Molar relationship(Terminal Planes)
The mesiodistal relation between the distal surfaces of maxillary and mandibular 2nd deciduous molars is
called as terminal plane.
This is of three types:
1. Flush terminal plane, 74%
2. Mesial-step terminal plane,14%
3. Distal-step terminal plane,10%
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9. 3.Anterior Teeth Relationship
Overbite: It is the distance, which the incisal edge of the maxillary incisors overlaps vertically
past the incisal edge of the mandibular incisors.
Deep over bite, 5 years
The average overbite in the primary dentition is 2 mm.
Edge-to-edge bite: When the incisal edges of the two incisors are in the same plane.
Overjet: It is the horizontal distance.
The average in primary dentition is 1 to 2 mm.
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10. 4.Canine Relationship
The relationship of the maxillary and mandibular deciduous canines is one of the most stable in
primary dentition.
Class I:
Class II:
Class III
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12. MIXED DENTITION PERIOD
6 to 12 years, successional teeth, accessional teeth
First transitional period:
– Emergence of the first permanent molars
– Incisors transition
Inter transitional period
Second transitional period:
– Emergence of cuspids, bicuspids and the 2nd permanent molars.
– Establishment of occlusion.
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13. First Transitional Period
emergence of 1st permanent molars and exchange of deciduous incisors with permanent incisors.
The mandibular molars are the first
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14. First Transitional Period
If the 2nd deciduous molar is in flush terminal plane, then the erupting permanent molar will also be in
the same relation. For this, to change into class I relation the molar has to move 2 to 3 mm in a forward
direction, this is accomplished by:
■ Early mesial shift: primate spaces and thus establishing class I relationship
■ Late mesial shift: Leeway space
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15. First Transitional Period
– If the 2nd deciduous molar is in
mesial-step terminal plane, then the
erupting permanent molar will
directly erupt in Class I relation. But if
further growth occurs or if there is
more utilization of spaces the relation
can even change to Class III.
If the 2nd deciduous molar is in
distal-step terminal plane, then the
erupting permanent molar will erupt
into Class II relation.
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16. Flush terminal plane:
• Class I – 56%
• Class II – 44%
Mesial step:
• < 2 mm – 80% Class I
• 2 mm – 20% Class III
Distal step:
• Class II
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17. Exchange of incisors:
This period of transition is from 6½ to 8½ years.
incisor liability
This is 7mm for maxillary arch and 5mm for mandibular arch
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18. Exchange of incisors:
Some of the factors that helpin alignment of incisors by gaining space
are:
Utilization of interdental spacing of primary incisor, 4mm maxillary and 3mm mandibular
arch
Increase in inter canine arch width
Increase in inter canine arch length
Change in inter incisal angulation
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19. Inter transitional Period
In this period, the maxillary and mandibular arches consist of permanent incisors and
permanent molars that sandwich the deciduous canines and molars.
Thisphase lasts for1½ years and is relatively stable.
Only a few changes in the morphology of deciduous teeth are seen
because they undergo attrition.
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20. Second Transitional Period
This phase is characterized by replacement of deciduous molars and canines by
premolars and permanent cuspids
9 to 11 years of age
very critical for the alignment of the erupting permanent teeth
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21. Replacement of Deciduous Molars and Canine
• mesiodistal width of permanent canine and premolars is less than that of deciduous canine and
molars.
This extra space is called Leeway space of Nance
Class I relationship through late mesial shift
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22. Replacement of Deciduous Molars and
Canine
It is 1.8 mm (0.9 mm on each side) in maxillaryarch
and 3.4 mm (1.7 mm on each side) in mandibular arch.
E-space
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23. Eruption of Maxillary Canine
As the permanent maxillarycanines erupt theydisplace the roots of maxillary
lateral incisors mesially
distal divergence of the crown…
This is called Ugly DucklingStage or Broadbent phenomenon
This condition corrects it self's
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27. conclusion
ideally aligned or malalinged is the result of an complicated
synthesis of genetics and environmental relationship throughout
the early development stages of childhood.
A knowledge of growth and development of occlusion helps to
differentiate abnormal from normal relation of teeth and helps in
diagnosis treatment planning.
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28. References
1.Tandon S. (2018).Text book of pediatric dentistry, third edition. Jaypee Brothers.
Pp;174 to 184.
2. Marwa N. (2018). Text book of pediatric dentistry, third edition. Jaypee Brothers.
Pp;161 to175.
3. Dean JA. Management of the developing occlusion. In: McDonald and Avery’s
Dentistry for the Child and Adolescent. 10th ed. Maryland Heights, Mo.: Mosby
Elsevier; 2015:415-78
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