the objective of this research is to compare the clinical effectiveness of the conventional lingual arch space maintainers with three-dimensional printed space maintainers.
Apparently, healthy cooperative children have recently prematurely loss of more than one mandibular primary molar in any of the quadrants, full erupted mandibular first permanent molars in both sides, and whose lower permanent incisors have erupted
The permanent successors of the lost primary molars were not expected to erupt within 6 months
Angle's class 1 occlusion with normal primary molar relation
Caries-free and periodontally healthy abutment teeth
children exhibited poor oral hygiene, para-functional oral habits, severe crowding, space loss, and abnormal occlusion
Extraction of primary molars exceeding three months.
Radiographically, absence of permanent successor.
uncooperative children