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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
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