Introduction 

To many parents and child care providers, losing a milk tooth earlier is not a serious one. But in reality, the early loss of primary teeth have serious consequences in the alignment of permanent teeth. But, how can we manage it? There is a simple device called Space Maintainer. A space maintainer is a fixed or removable appliance designed to preserve the space created by the premature loss of a primary tooth or a group of teeth. If the successive permanent tooth erupts within 6 months of the loss of primary tooth, no space maintainer is required.

Objectives 

• Preservation of primate spaces

• Preservation of the integrity of the dental arches (maintain the mesio-distal relationship in a given arch)

• Preservation of normal occlusal planes 

• In anterior space maintenance, it should aid in aesthetics and phonetics.

Classification of Space Maintainer

Generally, it can be fixed or removable or semi-fixed.

Fixed appliance:

Class Ia - Non functional: bar type; loop type

Class Ib - Functional: pontic type; lingual arch type

Class II - Cantilever type: Distal Shoe; band & loop

Removable appliance:

Acrylic partial dentures

Mathewson classified it into: Band(crown) & loop; Nance holding arch; Fixed lingual arch; Intraalveolar appliance (Distal Shoe)

Fixed appliances

These are appliances that are fixed using bands or bonds.

Band and loop:

It is an unilateral, non functional, fixed space maintainer. It is indicated during the premature loss of first molar in primary dentition or primary molars in mixed dentition. It can be given bilaterally also.

Crown and loop:

It is an unilateral, functional, fixed space maintainer. If the abutment tooth is carious, remaining tooth structure is less, exhibit hypoplasia, or underwent any endodontic procedures, crown and loop is preferred. 

Band and bar:

Similar to band and loop but instead of a loop a bar is placed. 

Broken stress” type appliance – prevents intolerable loads from being thrust on the supporting teeth. The stress breaker should be designed to allow vertical movement of the supporting teeth consistent mesiodistal relationship for this reason, one of the most successful types of retainers.

Nance palatal arch:

It is a bilateral, non functional, fixed space maintainer. It prevents the mesial migration of maxillary molars. It does not contact the anterior tooth but an acrylic button is placed in the anterior palate - it provides the resistance for anterior movement of posteriors. 

Nance palatal arch may be used in maintaining the maxillary first permanent molar positioning when there is bilateral premature loss of primary teeth, with no loss of space in arch and a favorable mixed dentition analysis.

Transpalatal arch:

It is a bilateral, non functional fixed space maintainer. It is used to stabilise the maxillary first permanent molar if the primary molars are need to be extracted. It is used if one side of the arch is intact and multiple missing teeth are present in the other arch. 

Lingual arch:

It is a bilateral, nonfunctional, fixed space maintainer. It is used for maintaining the arch perimeter. It is used in the mandibular dentition. It should be given only after the eruption of permanent mandibular incisors since the wire may interfere in the eruption of them.

Distal Shoe:

It is an unilateral, non functional fixed space maintainer. It is used when the primary second molar is lost before the eruption of the permanent first molar. It guides the permanent first molar to its normal eruptive position.

Roche’s distal shoe is a widely used one. A L shaped bar is soldered to the distal surface of the abutment through a band or crown. The tip of the L shaped bar is positioned intragingivally such that it is below the mesial surface of the  erupting permanent first molar. The right angle bend of the bar is such that the bar is directed along the mesial surface of the permanent molar. 

It is contraindicated in patients with bleeding disorders, mentally challenged children, children with poor oral hygiene etc.