Guidelines on the use of space maintainers following premature loss of primary teeth.

To formulate evidence-based guidelines on the appropriate use of space maintaining appliances to prevent or reduce the severity of malocclusion in the permanent dentition following the premature loss of primary teeth.Placement of lingual arch, palatal arch, band-loop, crown-loop, and intra-alveolar space maintainers.Reduced prevalence or severity of space loss in the primary or mixed dentition, reduced prevalence or severity of malocclusion in the permanent dentition measured as significant changes in: crowding, ectopic eruption, impacted teeth, Angle's class II or III occlusion, crossbite, deep overbite, deep overjet, or midline shift.Articles published from 1966 to 1996, located though Medline searches. Only clinical trials, cohort studies, case-control studies, or large case series were considered.Relevant clinical findings were evaluated and categorized using evidence-based methods and values established by the Canadian Task Force on the Periodic Health Examination. A recommendation was developed for the use of space maintainers.The potential benefits of using space maintaining appliances include reduced prevalence or severity of: crowding, ectopic eruption, tooth impaction, crossbite, excessive overbite and overjet, and poor molar relationship. Other advantages include the potential for considerable cost savings by reducing the need for future orthodontic treatment. The potential disadvantages of using space maintaining appliances include soft tissue impingement, interference with eruption of adjacent teeth, pain, plaque accumulation, caries, and broken, dislodged or lost appliances.There is poor evidence to recommend for or against the use of space maintainers to prevent or reduce the severity of malocclusion in the permanent dentition (see Table 1, Recommendation C) Decisions regarding the use of space maintainers must therefore be guided by factors other than scientific evidence.