Which space maintainer is most appropriate following premature loss of a primary molar when the permanent successor has not yet erupted and the adjacent permanent teeth are present?

A band and loop space maintainer is the most commonly used and appropriate appliance for maintaining space following premature loss of a single primary molar when the permanent successor has not yet erupted. It consists of a metal band cemented on the adjacent tooth with a wire loop extending over the edentulous ridge to prevent mesial drift of adjacent permanent teeth. It is passive (does not move teeth) and is suitable for unilateral single tooth space. A distal shoe appliance is used specifically when the permanent first molar has NOT yet erupted (it extends subgingivally to guide eruption). A lingual arch or Nance arch is used for bilateral or full-arch space maintenance.