Bilateral space maintainers: a 7-year retrospective study from private practice.

PURPOSE The purpose of this study was to report survival times and problems encountered with bilateral space maintainers placed over a 7 year period. METHODS Charts were reviewed for all patients who had bilateral space maintainers placed between January 1, 1996 and December 31, 2003. Appliance lifetime and problems encountered were recorded and assessed on July 30, 2005, if still in use. Failures were recorded as: (1) cement loss; (2) solder breakage; (3) split band; (4) eruption interference; (5) bent wire; (6) loss; or (7) not specified. Also recorded were: (1) failed appliances; (2) transferred patients; and (3) those lost to follow-up. RESULTS A total of 482 space maintainers were evaluated, with 114 failures (24%) and 349 successes (72%). Of the 114 known failures: 68 (60%) were from cement loss; 12 (10%) were from solder breakage; 11 (10%) were from split bands; and 13 (11%) were from reasons not specified. No statistical differences were noted between types of failures or between genders. Mean pooled survival times were 20 months for lingual arches and 23 months for Nance appliances, with no statistical differences between arches, except in successful appliances where Nance was superior (P = .011). Of the 114 failed appliances: 44 (39%) were not recemented or remade, which was considered clinically successful; 51 (45%) were recemented; and 19 (17%) were remade. Eight appliances were lost to follow-up or transferred. CONCLUSION The majority of bilateral space maintainers (72%) lasted their anticipated lifetimes.