Intra alveolar maintainer
Premature loss of the second primary molar generally leads to inadequate eruption in the alveolar bone of the first permanent molar that tends to migrate mesially. As a result, space is lost and often the second premolar is impacted. Therefore, to guide the first permanent molar, a subgingival extension is added to provide intra-alveolar maintenance. Apart from this extension, the appliance is approximately the same as the unilateral space maintainer.
A band is fitted on the first primary molar. The wire, soldered onto one end of the band, extends towards the distal surface of the second primary molar. A stainless steel splint is soldered onto the distal surface of the loop and is inserted into the space left by the lost tooth. The subgingival splint serves as a guide plane to the first permanent molar in order for it to erupt into the proper position. Once eruption is over, treatment must be continued with a unilateral space maintainer.
Indication of the location of the subgingival splint