Space management

Space maintenance:Space maintenance can be defined as the provision of an appliance (active or passive) which is concerned only with the control of space loss without taking into consideration, measures taken to supervise the development of the occlusion.

Space maintainers:Space maintainers can be defined as appliances used to maintain space or regain minor amounts of space lost so as to guide the unerupted tooth into a proper position in the arch.

Ideal requirements: Maintain the desired mesio-distal dimension of the space Should not interfere with the vertical eruption of the adjacent

teeth (interarch space maintenance) Should not interfere with the eruption of the permanent teeth Provide mesio-distal space opening when it is required Maintain individual functional movement of the teeth.

Selection of appliance Patient cooperation: Removable versus Fixed Appliance integrity: According to Wright Mandibular

removable appliances are . most susceptible and fixed appliance is better

Maintenance Modifiability Limitations Cost

Classification:

Fixed and removable

Removable: Fixed:

Cast partial and wrought Banded and bonded

Active and passive Active and passive

Functional and non functional Functional and non functional

Band and Loop Crown and loop Lingual arch Nance’s palatal arch Distal shoe Transpalatal arch Band and bar or crown and bar

Fixed space maintainers

Components Band Loop/archwire Solder joint Auxillaries

Bands

Band types Loop bands: Tailored bands Preformed seamless bands:

Band material

Area DimensionsAnterior 0.003 x 0.125 x 2 inches

Bicuspids 0.004 x 0.125 x 2 inches

Molar (dec) 0.005 x 0.180 x 2 inches

Molars (perm) 0.006 x 0.180 x 2 inches

Band construction Separation Band formation Welding Soldering

1) Separation

Brass wire: Elastic threads

0.015-0.020 inch soft brass wire. Elastic threads

Young patients with thick periodontal membrane

Gentle force over prolonged time period

Painful Painless at insertion

2) Band formation

I. Direct band formation: ( pinching ) Inciso-cervical or occluso-cervical contouring using Johnsons

contouring pliers Weld the ends of the band material and make a loop Howletts band forming pliers are used to form the bands Position on the tooth Pinch on the cuspal areas & not on groove areas (difficult to

adapt band in groove areas) Upper molar band: pulled from palatal side (seam at mesio-

lingual line angle) Lowe molar band: pulled from buccal side (seam at mesio-

buccal line angle) The edges of the seam must be parallel to each other When insufficient clinical crown height: peak band forming

pliers

II. Festooning

Contouring of the band to follow gingival contour proximaaly Level of the band adjusted at the marginal ridge Distal side require more trimming since crown is angulated

distally, thus lower position of the distal marginal ridge and raised position of the gingival

III. Trimming Reducing on the buccal and lingual surface if required

adjusting occluso-cervical length.

IV. Folder flap method After formation of seam, cut off the excess Fold the remaining portion on the lingual surface of the tooth Spot weld the folded over portion Crimping may be required to provide rolled retentive edge Occlusal margins are approx. 1 mm below the proximal ridges Gingival margins are 0.5 to 1.0 mm into the sulcus (chk for

blanching) Buccally it should be just below the contact of opposing cusp Lingually it should be just below the lingual groove

3) Welding Portion of metal being joined melted and flowed together Electric spot welding is usually done Resistance of material produces heat and caused fusion

4) Soldering Two metals are joined by intermediary metal of lower fusion

temperature Solders used are silver containing solder (silver + copper +zinc

+ tin) Flux used to reduce fusion temperature Finishing with green stone and poilishing with rouge

Appliances

Band and loop space maintainer (Fixed, non functional, passive space maintainer)

Indications Premature loss of first decicious molars When the unerupted molar is 2 yrs frm its clinincal eruption &

root length is less than 1/2

Contraindications Extreme crowding and space loss High caries activity

Disadvantages Space loss of more than one tooth Nonfunctional Gingival slipping of loop Loss of 2nd deciduous molar before eruption of 1st premolar

RationalePremature loss of first deciduous molar leads to following sequale

Distal shift of primary canine Mesial shift of primary secon molar and first permanent molar Mesially erupting first permanent premolar along the mesial

surface of 2nd molar Permanent canine is blocked out of the normal alignment

Construction The 2nd deciduous molar is usually banded 0.030-0.035 inch archwire loop is soldered to the band The loop spans the edentulous space and contacts the primary

canine on its distal surface at the contact point (if below the contact point, chances of it slipping gingivally)

The loop should not interfere with the erupting permanent tooth

Modifications

Loop on only one side, but less stable Occlusal rest on the tooth to prevent gingival slipping of the

loop. This may hamper the erupting permenant tooth. Crown and loop, where banding is not possible or grossly

destructed crown Crown and bar

Lingual arch space maintainer (Fixed nonfunctional passive mandibular appliance)

Indications Bilateral loss of mandibular posterior teeth (rare in primary

dentition) Minor movement of anterior teeth Maitainence of leeway space Minor space regaining

Contraindications Before the eruption of mandibular permanent incisors

Disadvantages Loss of cemntation and solders May cause untoward tooth movement

Rationale For bilateral loss instead of giving two band and loop

appliances, lingual arch serves better and also prevents lingual tipping of the mandibular anteriors and maintains arch perimeter

Construction 1st permanent molars are usually banded 0.32-0.40 inch lingual arch wire is soldered to lingual surface

of the banded tooth Rarely 2nd deciduous molars may also be used

Removable lingual arch Instead of soldering the archwire to the band, the archwire is

attatched by a pin and tube mechanism to the bands Vertical tubes on the bands (on the lingual groove and parallel

to long axis) into which the pin precisely fits Used for active movement when less than 5 degrees Easily adjusted and removable

Modifications Auxillary springs incorporated for individual tooth movements Loops incorporated mesial to 1st permanent molar for limited

tooth movements Lingual horizontal tube used to counteract the resistance to

movement provided by the vertical tube on the unaffected side Ellis loop lingual archwires are preformed arch wires

consisting of ellis vertical lingual tubes and are time saving

Fixed lingual arch The soldered lingual archwire should contact the cingulum of

the mandibular anterior teeth The archwire contacts slightly above the gingival papilla The wire should lie in the gingival third of the primary molar

(if present) and rest in middle thirds of the molar bands In edentulous areas the wire is curved away from the soft tissue

by approximately 1 mm The archwire should contact the band for 3-4 mm for sufficient

solder joint strength To accommodate the distal movements of the primary canines

into the primate spaces two omega bends can be incorporated in the area to avoid interference (Konstantinos)

Adjustment loop are also incorporated to allow for adjustments if needed (Hotz)

Passivation Lingual archwire is pasivated by heating it to a dull brownish

appearance while keeping the wire lingually on the cingula

Distal shoe space maintainers (intra alveolar, eruption guidance space maintainer)

The fixed distal shoe space maintainer was reported by Willets in 1932. This was cast gold appliance as not popular coz of its increased cost.

IndicationsEarly loss or removal of second primary molar to the eruption of first permanent molar Can be used in cases of bilateral space loss

ContraindicationsInadequate abutment teeth due to multiple teeth lossPoor patient cooperationCongenitally missing first molarsMedical conditions like blood dyscrasisas, CHD, Rheutmatic fever, DM or generalized debilitation

DisadvantagesOverextension caused injury to permanent tooth budIf under extended it may allow molar to tip into the space or under the bandPrevents complete epithelialisation of the extraction socket

RationaleEarly loss of deciduous second molar leads to the followingFirst permanent molar shifts mesiallyIf extractions were performed prior to emergence of 1st molars then it resulted in permanent space lossAfter eruption of the second molar but prior to eruption of 1st biscuspidPeriod of emergence of second molar is crucial because distal to first molar a growth centre existsFirst bicuspid however generally erupts first into this space distally sometimes impacting second bicuspids

ConstructionCommonly used distal shoe appliance was described by Roche in 1942.It’s a crown and bar or a band and bar type of applianceThe Roche’s appliance had a V-shaped gingival extension as against Willets which had a bar extensionIt can be fixed or removable

Distal extension In the lower arch, the contact area of the distal extension

should have a slightly lingual position over the crest of alveolar ridge

In the maxillary arch the contact area of the distal extension should have a slightly facial extension in order to prevent rotations of tooth and appliance

Width Adequate width must be provided to prevent slipping Width should be approximately half the width of the contact

area

Length of distal extension Ideally measure 2nd molar before extraction

If already missing, use radiographic measurements between distal surface of 1st dec molar to 1st perm molar (appliance may be over extended as the 1st perm molar erupts mesially from a distal direction)

Measure M-D width of the 2nd primary molar on the opposite side

Depth of gingival extension 1 mm below the marginal ridge so as just to catch the mesial

marginal ridge of the tooth

Considerations since non functional appliance doest provde occlusion the

erupting 1st perm molar may tip over the plane of occlusion functional cast gold type appliances require two abutments (not

feasible), hence a retentive groove in mesio facial surface aids in retention

Nance’s palatal arch or Nance’s space holding appliance (Fixed nonfunctional passive maxillary arch appliance )

Preventive lingual wire as described by Nance in 1947

Indications Bilateral loss of deciduous molars Can be combined with habit breaking appliance

Contraindications Palatal lesions If the molars have not erupted

Disadvantages Tissue hyperplasia and infection due to poor oral hygiene due

to the acrylic tab

Rationale Whe the deciduous molars are lost prematurely, the primary

canines moves distally and the 1st permanent molars tends to move mesially (after the eruption of 1st perm molars)

In these cases the first perm molars are banded to prevent the space closure

Appliance cant be applied before the eruption of 1st permanent molars

Construction Consist of bands around the first permanent molars Arch wire soldered on the palatal surfaces to the banded molars

and extends forwards into the palatal vault The anterior portion of the archwire is prvided with an acrylic

tab which rests against the palatal ault The tab is kept short of the rugae area The tab prevents anterior movement of the arch wire loop U-bend is given in the wire for retention of the acrylic 1-2 mm

away from the tissue

Transpalatal arch (TPA) (Fixed nonfunctional passive appliance)

Indications Unilateral loss of deciduous molars

Contraindications Bilateral loss of molars Palatal tori Before eruption of the perm molars

Disadvantages May cause the molars to tip together

Rationale Migration and rotation of an tooth is caused rotation around the

lingual root, by preventing this space loss is prevented The tooth from the opposite side side serves as the anchor In cases of unilateral space loss of dec molars, instead of using

an extended band and loop a trans palatal arch serves better

Construction The first perm molars are banded

An arch wire extens straight across the palate between the bands and is soldered to the palatal aspects of the band

The molar on the unaffected side (where there is no pri mlar loss) will stabilize and prevent the mesial migration of its antimere.

Bonded space maintainers

Suggested by Palmer in 1979 Reduces time in application and construction A triangular meshpad is adapted to mesial surface of distal

abutment and distal surface of mesial abutment For additional retention the mesh can be extended slightly on

the facial and lingual surfaces The space maintainer tube is welded onto the mesh and wire

(ordinary round wire) is welded anteriorly Vacuum molded template is formed over the space maintainer

Antrum and Marstander in 1983 suggested use of multistranded 0.32 inch orthodontic wire and an auto polymerizing resin.

Athanasios in 1984 suggested solid steel foil pad bases and two sections,

round retainer wire and stainless steel tubing

Advantages Easy fast and economical No banding or impressions are required Completed in one appointment Can be used for posterior space of any length Possible decalcification and PDL trauma associated with

banding is eliminated Can be used on partially erupted teeth as well

Modified bonded space maintainers

Liegeois in 1999: Slots and occlusal shores prepared on primary teeth and a

sanitary pontic is placed to make it functional. Alloy used is chrome cobalt

Coican in 1992: 2nd molar bracket bonded to buccal surface of erupting first

molar rectangular wire used to span the edentulous area and provide

light cotact against the deciduous first molar.

Disadvantages of fixed space maintainers

Failures with lingual arch appliances Cement and solder failure Tissue lesions with band and loop and distal shoe Eruption interference by lingual arch in some cases

Removable space maintainers

Indications Premature primary molar loss: space maintainence along with

restoration of mastication Where supraeruption has already taken place a nonfunctional

one may be given In anterior teeth loss: speech and aesthetics, an RPD is

indicated Multiple teeth loss, a removable one is preferred over fixed

appliances Permanent molars haven’t erupted and bonding and banding

isn’t possible High caries risk child, maintainence is poor and fixed space

maintainers are contraindicated

Classification

I Unilateral maxillary posteriorII Unilateral mandibular posteriorIII Bilateral maxillary posteriorIV Bilateral mandibular posteriorV Bilateral maxillary and mandibular

posteriorVI Bilateral mandibular anterior posteriorVII Primary/permanent anteriorVIII Complete primary teeth loss

Disadvantages Patient cooperation Lsot or broken by the patient Lateral jaw growth may be restricted if clasps are incorporated Irritation of underlying soft tissues May not maintain space durin eruption of tooth

Instruments used for band pinching and crown adaptation

Straight how Curved how Anterior double beak Posterior double beak Universal Band remover Separating plier Johnson’s contouring plier Crimping plier