Short-term efficacy of vacuum-formed maintainer for deciduous second molar space maintenance in the mixed dentition: A single-centre, randomized controlled clinical trial.

OBJECTIVE To compare the efficacy of vacuum-formed and banded space maintainers for deciduous second molar space maintenance during the mixed dentition. SETTING AND SAMPLE POPULATION The study sample comprised thirty children in the mixed dentition (age range, 5.9 to 9.8 years) with early loss of at least one deciduous second molar. METHODS This was a parallel-group, randomized, active-controlled clinical trial. Patients were randomly allocated to space maintenance performed with vacuum-formed or banded space maintainers with a 1:1 allocation ratio. The main outcome was any change in mesiodistal width of the extraction space. Secondary outcomes included the lingual rolling or axial rotation of the permanent first molar adjacent to the extraction site and extrusion of the antagonist tooth. Dental casts were obtained before appliance installation (T0), after 3 months (T1) and after 6 months (T2). Digital dental casts were measured using Dolphin 3D software. Chi-square, t test or Mann-Whitney and ANOVA or Friedman test were used for intra- and intergroup comparisons (P < .05). RESULTS Baseline characteristics were similar between groups except for chronological age. Statistically, but not clinically significant space loss (mean, 0.32 mm; SD, ± 0.39) occurred with the vacuum-formed space maintainer only at the first trimester (T0-T1). Lingual rolling and axial rotation of the first permanent molar were not significant, as well as extrusion of the antagonist tooth. CONCLUSIONS The results of this study suggested that both tested devices were effective in maintaining space after early extraction of the deciduous second molar over a period of 6 months.