PASSIVE SPACE CONTROL

Dr S.E. Jabbarifar;Isfahan Dental School,Pediatric Dentistry Departement

2009

Prerequisite knowledge

Understand that arch length is greatest at age four years

Tooth position is maintained by balance of forces – shift vs. drift

Greatest amount of space closure – within first 6 months of premature tooth loss

Sequence & timing of exfoliation/eruption

Space control vs. space maintenance

Space control Dynamic Careful ongoing supervision

Space maintenance Utilization of appliance to preserve existing

space Not always the rule!

Variables influencing space control

Oral musculature & habitsTime elapsed since extractionDental age, eruption sequence & bony

coveringAvailable spaceInterdigitationAbsence of anomalies

Considerations in premature 1o tooth loss

Preserve the arch length!Causes:

Anterior – primarily trauma, caries Posterior – primarily caries

If space lost: Space maintenance Space regaining No treatment

Space loss in primary and mixed dentitions

Unrestored interproximal caries reduce arch circumference!

“first line of defense” = Class II & SSC restorations

Natural tooth is the best space maintainer

Planning for space maintenance

No medical contraindications

Patient must be dentally fit

Patient must be able to demonstrate good OH

Planning for space maintenance

Parents must all understand costs involved

Parents must understand importance of & be willing to attend regularly for appliance supervision/maintenance – teeth lost in primary dentition stage may cause delayed eruption of succedaneous teeth

Periodic recementation may be required

Primary Incisors

Primary Incisors

Primary Incisors

Why replace primary incisors?

Primarily for esthetic reasons

Rarely see long-term effects on speech development and function

Once 1o cuspids have erupted in occlusion the anterior arch length is established

Primary Incisors

Problems with replacement:

Appliances are weak

High maintenance – close monitoring req’d

Frequent alterations as dentition changes

Appliance may enhance caries risk

Primary Incisors

Primary Incisors

Primary Incisors

Primary Incisors

Primary Canine

Loss due to trauma or caries – rareSpace maintainer: B&L vs. RPD

Must be removed to accommodate lateral

No space maintainer: Midline shift Lingual collapse in mandible

Premature loss of primary molars

Band-loop space maintainer

Indications: Unilateral loss of the 1st primary molar before

eruption of the 1st permanent molar

Unilateral loss of the 1st or 2nd primary molar after eruption of the 1st permanent molar

Bilateral loss of the 1st primary molars before eruption of the permanent incisors and 1st permanent molars

Bilateral loss of the 2nd primary molars after eruption of the 1st permanent molar

Early loss of the 1st primary molar

Early loss of the 2nd primary molar

Other indications

Deflection of succedaneous tooth

Band-loop space maintainer

FABRICATION & DESIGN

Band-loop fabrication

Technique: Properly fitting band on abutment tooth

(pg. 389 – Pinkham) Segmental impression

(compound/alginate) Remove band from tooth & secure in

impression Create working model

Band-loop fabrication

Sectional impression tray

Green or red compound

Band-loop fabrication

Band-loop fabrication

Band-loop fabrication

Band-loop design

Loop should be wide enough bu-li to allow eruption of bicuspid (8 mm)

Loop should not restrict physiologic movement of adjacent teeth (eg. lateral movement of primary canine)

Band-loop design

Loop should not impinge on soft tissue

Loop should be in close approximation to ridge

Band-loop cementationApply floss ligatureTry-in / seat band

completelyLoop should contact

abutment below contact point

No soft tissue impingement

Cementation in properly isolated, dry field

Check/adjust occlusion

Try it in first!

Loop impingement

Loop impingement

Loop impingement

Lingual arch

Lingual arch

Indications:

Bilateral single or multiple tooth loss in mandible

Not recommended when primary incisors still present

Lingual arch

Lingual arch design

Archwire should rest on cingulae of incisors 1-1.5 mm above gingival margin

Removable vs. soldered

Lingual arch design

Solder joint should be in mid-third and parallel to band

Wilson loops

Archwire should be below plane of occlusion posteriorly

Lingual arch fabrication

Fit molar bands

Compound/alginate impression – accurate especially in lingual sulcus & lower incisor area

Lingual arch fabrication

Secure bands in impression …

…create working model

Lingual arch cementation

Check for passivity on the model and in the mouth before cementation

Archwire should be in contact with lower incisor cingulae

Lingual arch cementation

Dry field

GI or polycarboxylate cement

No soft tissue impingement

Transpalatal arch

Transpalatal arch

Rarely recommended for bilateral tooth loss in maxilla

Can prevent mesio-palatal rotation of palatal root of Mx 1st permanent molar but allows mesial tipping of molars & space loss

Transpalatal arch

May have an indication for use when one side of the arch is intact but several primary teeth are missing contralaterally

Some designs incorporate omega loop: when active can prevent bodily movement of molars

Nance arch

Nance arch

Used commonly in maxilla for bilateral tooth loss

Incorporates acrylic button in contact with palate to prevent molars from tipping

Can be very unhygenic

Nance arch

Nance arch fabrication

Bands fitted on molars

Mx impression in compound/alginate

Working model

Nance arch fabrication

Archwire will traverse the palatal vault

Nance arch fabrication

Adapted archwire is soldered to bands

Acrylic button is added to embed the wire

Nance arch fabrication

Completed arch ready for try-in and cementation

Ensure acrylic button in firm contact with palate

Crown-loop space maintainer

Crown-loop space maintainer

Indications:

As for band-loop

Abutment tooth requires full coverage SSC due to multi-surface caries or pulp treatment

Crown-loop fabrication

Abutment tooth prepared for SSCProperly contoured SSC seated, but not

cementedCompound impressionSSC placed into impressionWorking modelAnother SSC fitted and cemented with

temporary cement

Crown-loop space maintainer

Crown-loop space maintainer

Crown-loop space maintainer

Crown-loop cementation

Temporary SSC removed, under LA if necessary

Try-in crown-loop to verify loop contours

Cementation in dry field

Crown-loop space maintainer

Disadvantages:

If solder joint fails, there is no way to repair the appliance without entire re-make

Cost is higher (extra SSC)

Band-loop over SSC

Band can be fitted over SSC as alternative to crown-loop

Bonded space maintainer

Difficult to retain due to shearing forces of occlusion

Flexure in function will de-bond

Difficult to adjust

Removable appliances

Indicated for mulitple primary tooth loss when no suitable abutment teeth exist

Need to restore occlusal function over longer span

Clasping difficult for primary teeth therefore retention a problem

Compliance issues

Removable appliances

INTRA-ALVEOLAR SPACE MAINTENANCE

D362/QP362

Division of Orthodontics and Paediatric Dentistry

2004-2005

Karen M. Campbell, DDS

Premature loss of the 2nd primary molar

If the 1st permanent molar is erupted, can use conventional B & L from 6 to D

Premature loss of the 2nd primary molar

Band & loop from D to 6

Difficult to band D’s

Indications for intra-alveolar space

maintenance

Premature loss of the 2nd primary molar prior to the eruption of the 1st permanent molar

Contraindications

Medically compromised:

Cardiac patients requiring SBE prophylaxis

Immunosuppression

Chemotherapy/radiation therapy, pre-BMT

Demonstrated lack of commitment to follow-up

Distal Shoe

Provides a guiding plane for the eruption of the 1st permanent molar

Dentist’s responsibility

Mark on the working model the distal terminus of the appliance

Dentist’s responsibility

Provide measurement from radiograph

Mark depth of shoe with cut on model

Shoe should be 1 mm below mes marginal ridge of the 1st permanent molar

Completed appliance

Immediate insertion

Follows extraction – can better visualize placement of shoe

Area already anesthetized

eliminates potential for 1st permanent molar drift

Cemented appliance

Crown with distal shoe

D prepared for SSC; E to be extracted at later appt

Crown with distal shoe

Segmental impression with crown inserted

Crown with distal shoe

Tooth temporized with SSC

Crown with distal shoe

Crown with distal shoe

Extraction of the E and preparation for cementation

Crown with distal shoe

Cementation Confirmation by radiograph

Following eruption of the 1st permanent molar

Distal shoe no longer appropriate – 1st permanent molar may tip mesially above shoe

Parents must be aware of need for second appliance from the beginning

Conventional B & L or lingual arch may be required

Drawbacks of the appliance

Can only replace a single tooth due to its cantilever design

Inherent lack of strengthCannot restore occlusal functionD’s are very difficult to fit bandsEpithelium perforated in area of distal

shoe