Study the predisposing factors of root resorption during orthodontic uprighting treatment of impacted mandibular third molars

Objective > To analyse the amount of root resorption of mesially or horizontally impacted mandibular third molars after orthodontic uprighting treatment. Materials and methods > Twenty-four patients with an age range of 20 similar to 26 years old who had mesially/horizontally impacted third molars with complete root formation. And those with decayed or missing the mandibular first molar on the same side were selected. The lower third molars were uprighted and the extraction spaces closed. Root resorption was compared with paired t-test. The related risk factors for root resorption were compared with Pearson correlation analysis. Result > The average uprighting time was 10.00 months (4 similar to 16 months). The study showed that all the impacted third molars were uprighted and got satisfactory outcomes after treatment. Shortening in length of mandibular third molar roots was detected at the end of the treatment, but no statistically significant differences were found (P < 0.05). Root resorption was correlated with the duration of uprighting and the distance that root moved. Conclusion > Impacted mandibular third molars were uprighted and the amount of root resorption of third molar after treatment was not increased. The duration of uprighting and the distance that root moved influence the degree of root resorption.