2. The size of the dentition in relation to the jaw size
3. The etiology of dental arch crowding
First Theory Second Theory
4. The effects of excessive dentition size
Overlapping and displacement of teeth Impaction of teeth Ectopic eruption of teeth
Space closure after extraction
5.
6. • The effects of early loss of primary teeth:
• 1) Function and oral health:
• 2) Over-eruption of opposing teeth
• 3) Psychological effects on child and parent
• 4) The effect on position of permanent teeth
a) The effect on the shape of the dental arch "collapse"
b) The effect on the size of the dental arch
7. • The following categories of conditions can be outlined, in which
premature loss of primary teeth may have adverse effect or no
adverse effect on the position of the permanent teeth:
1) When there is ample space in the dental arch:
2) When there is just enough space for the permanent teeth to erupt
without crowding:
3) When there is slight crowding potential in the dental arch for the
permanent teeth:
4) When there is severe crowding potential in the dental arch for the
permanent teeth:
8. Space maintainers: were defined as the appliances that prevent the loss of the
dental arch length and which in turn guide the permanent tooth into correct
position in the dental arch.
Ideal requirement of space maintainers:
1. Should maintain the desired mesiodistal dimension of the space.
2. Should not interfere with the eruption of permanent teeth.
3. Maintenance of functional movement of the teeth.
