Dental space maintenance is essential in cases of premature loss of primary dentition to prevent malposition, supra-eruption, impaction, or crowding of the developing permanent teeth. Many types of space maintainers are available and each type is specifically designated for particular indications. Space maintainers have many classifications according to their design, their fixation pattern, their position, and their site. They can be fixed, semi-fixed, or removable, with or without loops, wires, and/or bands, unilateral or bilateral, and are placed on mandibular or maxillary arches. The most commonly used space maintainers are loops and bands, fixed lingual arches, Nance appliances, and transpalatal arches. Though space maintainers are generally safe, several complications are sometimes inevitable. This article will review the different types of space maintainers and their application and will discuss their indications and potential complications.