9- managing and maintaining space

Look at clinical cases in this ppt

What are the 5 determinants of loss of dental space?

Mesial eruption of posterior teeth

Untreated interproximal decay/premature loss of temp tooth

Agenesia

Ankylosis

Ectopic eruption of upper 1st perm molars

What teeth do untreated interproximal decay or premature loss effect most?

Posteriors and canines distally

If contact point not reconstructed- space is created and invaded by mesial migration

What teeth frequently suffer agenesia?

L2ndPm

ULI

U2ndPm

LowerI

What is ankylosis?

Fusion between root cement and alveolar bone with disappearance of part of PDL- interrupts eruption of tooth

When tooth’s vertical growth stops- antagonist supraerupts and tooth distal to it mesially migrates

What is the ectopic eruption of U1stPermM characterised by?

Atypical and premature root resolution of distal root of U2ndTempMolars

This is caused by eruption of perm molar which conditions a great mesial inclination of the final molar to erupt. Sometimes even with the loss of the second primary molar

What 7 factors should be taken into account to decide where to maintain a space?

Occlusal relationship

Mixed or temporary dentition

Development of the permanent germ

Sector of the arch where the loss has occurred

Arch where the loss has occurred

Amount of space already wasted

Bone-dental discrepancy

When the 2nd primary molar is lost- how does it effect the occlusal relationship in the upper vs lower arch?

Space lost due to…

Rotation of upper 1st perm molar on palatal root

Tipping of lower 1st perm molar

In what dentition is space more easily recoverable?

Mixed over permanent

In case of having more than 2/3rds formed- eruption will be brought forward

The loss of what sector of the arch has the greatest impact?

Loss of incisors- little importance

Loss of canines- must reduce diameter of arch

Of primary 1st molar- not many consequences

Of primary 2nd molar- very important

In what arch where the loss has occurred is it harder to recover space?

Upper- bone less dense, bone loss occurs faster but recovery easier

Lower- bone denser, movement more difficult for recovery

What 3 situations should generate an alarm about space?

Eruption of the second premolars before first ones in the lower arch

Eruption of the canines before premolars in the upper arch

Asymmetries between the right and left side

What are the 3 consequences of premature loss of primary teeth?

Arch length reduction

Occlusal alterations

Malpositions in permanent dentition

How are space maintainers classified?

What’s the difference between a space maintainer and space reclaimer>

Space maintainer placed when there’s no previous loss of dental material that leads to shortening of arch

One space is lost with shortened arch- assess need to recover space

Indications of a removable maintainer

In cooperative patients

In patients with poor oral hygiene

When the replacement is far away

Always bilateral for retention reasons

Indications of a fixed space maintainer?

In uncooperative patients

In patients with good oral hygiene

When the eruption of the definitive is very close

Unilateral fixed space maintainers (3)

Crown loop

Band loop- never for more than 1 absence

Proprioceptive

Bilateral fixed space maintainers (3)

Transpalatal arch

Nance button

Lingual arch

5 Etiologies of premature loss of anterior teeth

Trauma

Ectopic eruption

No space

Cavities

Supernumerary teeth

3 etiologies for premature loss of posterior teeth

Cavities

Ectopic eruption of 1st perm molar

Chronological alterations of eruption

If there’s premature loss of primary 1st molar…

If good occlusion and space distribution- usually no treatment

If primary crowding- assess if need to place maintainer

Premature loss of primary 2nd molar…

Always need treatment

1- Before the eruption of the 1st perm molar:

- Intraosseous molar: wait until there is a gingival protrusion

- Extraosseous molar: place a proprioceptive maintainer

2. After the eruption of the 1st perm molar: usually a maintainer must always be placed