The Effect of Vitamin D₃ on the Alignment of Mandibular Anterior Teeth: A Randomized Controlled Clinical Trial

Abstract

Objectives . To investigate the effect of vitamin D 3 level on the alignment of mandibular anterior teeth in adults and explore the associated root resorption and pain perception. Trial Design . Multicentre, double blinded randomized clinical trial. Subjects and Methods . Adult patients aged 18–30 years, with moderate mandibular incisor crowding [Little’s Irregularity index (LII) 3–6 mm], needing nonextraction treatment with fixed orthodontic appliance, were randomly allocated into two groups with 1 : 1 allocation ratio. In the 1 st group (normal vitamin D 3 level group [ND 3 G]), vitamin D level was measured and corrected to normal before starting orthodontic treatment, while in the 2 nd group [control group (CG)] the vitamin D level was kept unknown until completion of the alignment phase. Outcome measures included mandibular incisor crowding using LII, orthodontically induced root resorption (OIRR), and pain perception. Independent sample t ‐test was used to compare the duration of treatment, the effectiveness of alignment, and OIRR between groups, while differences in pain perception were analysed by Mann–Whitney U ‐test ( P < 0.05). Results . Out of 87 patients recruited from four centres, 33 patients were randomly allocated into two groups (17 patients to ND 3 G and 16 patients to CG). Time elapsed for the complete alignment of the mandibular incisor crowding was one month shorter in ND 3 G (23.532% faster), and the improvement percentage was significantly higher in all periods when compared to the CG. The amount of OIRR was not significantly different between groups; however, pain during the first three days of alignment was significantly less in ND 3 G. Conclusions . Having optimal vitamin D 3 level reduced the alignment time and pain associated with orthodontic treatment, but it had no role in reducing OIRR. Registration . The trial was registered with ClinicalTrials.gov on 12 th April 2021 (registration number: NCT04837781 ).