A Retrospective Analysis of Distal Shoe Space Maintainers Placed in a Specialised Paediatric Dental Clinic

Background: Space management after the premature extraction of second primary molars remains a challenge. Distal Shoe space maintainers (DSSMs) have been recommended after such extraction before the eruption of first permanent molars (FPMs) to prevent space loss and subsequent complications. There is lack of evidence for their clinical use and possible complications after their insertion. Therefore, this study aims to investigate survival rates and complications of DSSMs. Methods: Digital patients' records were retrospectively screened for inserted DSSMs between 2014 and 2022, identifying 190 appliances in 141 children, of whom 113 appliances in 82 children had sufficient data to be included in the main outcome and survival analysis. Mean follow-up of the appliances and any reported complications were recorded. Results: Mean age of the included study sample (n = 82) at the time of insertion was 5.1 ± 0.93 years and almost identical to the whole sample (n = 141; 4.99 ± 0.90 years). Most children were uncooperative with high levels of caries (mean dmft: 6.6 ± 3.48). Appliances were mainly inserted under advanced behaviour management techniques such as general anaesthesia (n = 141, 74.2%) and nitrous-oxide sedation (n = 42, 22.1%). The main recorded complication was complete loss due to decementation (10.6%). Mean follow-up time was 17 months with a success rate of 83.2%. Kaplan-Meier survival analysis showed an estimated mean survival time of 42.7 months (SE 2.4, 95% CI 37.9-47.5). Conclusions: DSSMs were mainly placed under general anaesthesia in young children with high caries levels. The DSSM demonstrated acceptable clinical longevity till the eruption of the FPM, thus suggesting its use as a reliable option. Minor complications such as decementation could occur but are generally manageable.