The longevity of space maintainers: a retrospective study.
METHODS
This retrospective study investigated the longevity of 301 space maintainers fitted in 141 patients aged 3.4-22.1 years in the Department of Pediatric Dentistry at Leeds Dental Institute between 1991 and 1995.


RESULTS
Failure occurred in 190 space maintainers (63%), of which 36% were due to cement loss, 24% breakage, 10% design problems, and 9% were lost. Using the life table method, the median survival time (MST) for space maintainers was found to be 7 months. Band and loop (B&L) appliances had the highest MST of 13 months, while the lower lingual holding arch (LLHA) had the lowest of 4 months. Unilateral space maintainers survived longer than bilateral space maintainers (MST of 13 months vs. 5 months). Left B&Ls had a MST of 16 months, compared to only 4 months for right B&Ls, Gender, age, arch in which the appliance was placed, the operator planning it, fixed vs. removable, and adequacy of pretreatment assessment did not have a significant effect on survival time.
Qudeimat
M A
MA
Department of Child Dental Health, Leeds University, UK.
Fayle
S A
SA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002484:Cementation; D002648:Child; D002675:Child, Preschool; D003724:Dental Arch; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015993:Life Tables; D008297:Male; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D012189:Retrospective Studies; D012737:Sex Factors; D013027:Space Maintenance, Orthodontic / Q000295:instrumentation*; D013499:Surface Properties; D016019:Survival Analysis; D013997:Time Factors