Clinical performance and survival of space maintainers: evaluation over a period of 5 years.

The study investigated the clinical performance of 387 space maintainers fitted in 358 patients aged from 3 to 9 years in the Department of Pediatric Dentistry at the Faculty of Dentistry-University of Jordan from 1996 to 2000. Failure occurred in 119 appliances (30.7%), of which 49.6% were due to solder breakage, 32.8% from cement loss, 11% from soft tissue lesions, 4.2% from eruption interference, and 2.5% were completely lost. By using the Kaplan-Meier method, the estimated median survival time for space maintainers was 18 months. Lingual arches had the lowest median survival time of 14 months. Bands and loops, Nance appliances, and removable partial dentures had similar probability of survival. Fixed bilateral mandibular appliances recorded lower survival time than fixed bilateral maxillary appliances. Gender, age, type of dentition, fixed vs. removable, year of placement of the appliance and number of space maintainers fitted simultaneously in the same patient had no significant effect on survival of the appliances.