space maintenance

Question 1

primary dentition

Answer 1

1) amount of growth moderate
2) Rate of growth decreasing
3) dental arch growth esp posterior
–
1) 6 mo
- primary tooth eruption start
- generalized spacing
- primary forces tongue and muscles of mastication
2) 2 years
- primary tooth eruption completes
- primate spaces persist
- primary forces tongue and muscles of mastication

Question 2

intact dentition

Answer 2

1) transition to permanent dentition
- amount of growth steady by moderate until puberty
- rate of growth decreasing until puberty
—
1) 6-7 years
- permanent tooth eruption starts
- previous spacing closes
- erupting permanent teeth primary force on arch
2) 12-14 years
- permanent tooth eruption completes (except 3rd molars)
- crowding may develop
- - primary forces tongue and muscles of mastication

Question 3

no space loss

Answer 3

1) erupting permanent 1st molars
- mesial force
2) erupting permanent incisors
- distal force
3) no net movement if primary teeth are present

Question 4

non intact dentition

Answer 4

1) premature loss of primary tooth (Extraction)
- dramatic space loss esp if during active eruption of permanent tooth
- significant space loss for premolars
2) proximal tooth structure loss
- less dramatic space loss
- cumulatively create greater space loss if throughout dentition

Question 5

dental development influences on space loss

Answer 5

1) eruption sequence
2) space loss/crowding manifests in last tooth to erupt in affected quadrant
- ectopic
- blocked
3) need to make sure appliances use teeth that will be in place as long as it is required

Question 6

root development starts when eruptive movement starts

Answer 6

1) timing
2) early loss (before eruption starts)
- bone heals (stiff scarred bone)
- eruption delayed
3) late loss (after eruptive movement starts)
- eruption before bone heals
- eruption accelerated

Question 7

mechanics of space loss

Answer 7

1) permanent 1st molars
- mesial inclination
- physically contact primary 2nd molars as guide plane
2) if non intact arch
- maxillary : incomplete uprighting, rotation and tipping
- mandibular: incomplete uprighting, tipping

Question 8

rate of space loss

Answer 8

1) accelerators
- active eruption of permanent teeth in non-intact arch
- esp adjacent to space
2) unstable occlusion of existing teeth in arch

Question 9

prevention and management of space loss

Answer 9

1) appliances
- support arch stability and maintain arch length in non-intact arch
- do not restore stable occlusion
2) qualities
- passive (DOESNT MOVE TEETH)
- no interference with occlusion or eruption
- no irritation to tissue
- cleansable
- durable
- adjustable
- effecting until tooth which space is being held erupts

Question 10

promoting space loss

Answer 10

1) active eruption of permanent molars and or incisors at time of primary tooth loss
2) non intact arch
3) occlusion unstable
4) recent primary tooth loss without intervention
5) early primary tooth loss with time for healing of bony socket
6) crowding

Question 11

discouraging space loss

Answer 11

1)no active eruption of permanent molars and incisors at time of primary tooth loss
2) intact arch
3) stable occlusion
4) uncrowded
5) space maintenance intervention before extraction
6) late primary tooth loss without time for bone healing