-are indicated for pediatric patients who have lost their primary teeth at the age of four years old .
They are defined by " J.C Brauner" as : An applianced designed to retained a given area of space , generally in the primary and mixed dentition .
Also defined by Boucher's clinical dental terminology as : a fixed or removable appliance designed to preserve the space created by premature loss of a tooth
Fixed space maintainers is a space maintainer not intended to be removed by the patient , while removable space maintainers is a space maintainer designed for easy removal for cleansing and/or adjustments .
Requirements of a space maintainer :
- Should maintain the desired proximal dimension of space
- Should not interfere with eruption , speech , mastication
- Simple & strong
- Easily cleansable
- Does not restrict normal growth
Indications of a space maintainer :
- If the space after premature loss of deciduous teeth shows signs of closing
- If tooth is not ready to erupt
Contraindication of space maintainers :
- If the space shows no signs of closing
- when there is general lack of sufficient arch length and where space maintainer would further complicate existing malocclusion
- When succedaneous tooth is absent
- No bone observed radiographically overlying the erupting tooth
- when space available is greater than that of required
Classifications of space maintainers
According to Hitchkoch =
- Removable or fixed or semifixed
- with bands or without bands
- functional or not functional
- active or passive
- certain combinations of the above
According to Raymond C. Thurow =
- Complete arch ( lingual arch )
- Individual tooth
According to Hinrichsen ( 1962 ) =
- Fixed appliance ( Class 1 [ non functional types- bar type , loop type ] , [ functional types - pontic type or lingual arch type ] , class 2 )
Removable space maintainers :
According to Brauer J.C removable appliances may be indicated when : aesthetics is of importances , abutment teeth cannot support fixed appliance , cleft palate to be closed with the denture , when unerupted permanent teeth are expected not to erupt within 6 months , or the child has reached a mental age of two and a half years .
Removable appliances are contraindicated in : uncooperative child , Patient who are allergic to acrylic , epileptic child
Advantages of removable appliance : Easily cleaned , can be worn part time , facilitates chewing , band construction , keeps tongue in bounds .
Disadvantages : may be lost or broken , child may not wear it , jaw growth may be restricted if claspes are incorporated , inrritate the underlying soft tissues .
Types of removable appliances : Acrylic Partial denture , Complete dentures , or removable distal shoe .
Fixed space maintainers
Advantages of fixed type : Bands are used without tooth preparation or with minimum preparation of stainless steel crowns are used , does not interfere with passive eruption of abutment , jaw growth is not hampered , succedaneous permanent teeth are well guided to their positions , can be used for uncooperative children , masticatory functions are restored if pontics are placed
Disadvantages : Elaborate instrumentation with expect skill is needed , results in decalcification of tooth material under the bands , Supra-eruption of opposing teeth if pontics are not used .
Types of fixed space maintainers :
- Band and loop ( when single tooth is missing , contraindicated in high caries activity and if more than one teeth is missing )
- Modifications of band and loop : Crown and loop
- Lingual arch ( bilateral loss of molars after eruption of permanent incisors in lower arch )
- palatal arches ( nance palatal holding arch , transpalatal arch )
- Distal shoe appliance ( when second deciduous molar is extracted or lost before eruption of first permanent molar )
Steps in fabricating fixed maintainers :
- Band selection ( select the smallest band that will fit over the height of countour of the teeth , seated with finger pressure )
- Alginate impression taken
- Pour impression
- Draw design of band loop on cast
- maintanance and evaluation
- applicance removal