Objective: The present study was designed to evaluate and compare the changes in labial alveolar bone (LAB) and root length (RL) of mandibular incisors following orthodontic leveling and alignment with multistrand versus conventional single stranded NiTi archwires using Cone Beam Computed Tomography (CBCT).
Patients and methods: Twenty patients, 18 females and 2 males, with a mean age of 16 ± 2.1years were randomly selected and allocated into two equal groups: group I, where coaxial multistrand NiTi archwires were used for leveling and alignment; whereas group II conventional single stranded NiTi archwires were utilized. Mandiblular CBCT scans were obtained before treatment (T1) and immediately following complete leveling and alignment (T2) and analyzed for changes in LAB level and RL of mandibular incisors. Comparisons between both groups were performed using Mann-Whitney test and Friedman's test. Level of significance was set at p ≤ 0.05.
Results: Overall changes in LAB (T1-T2) of multistrand archwire group were -2.18 ± 1.55 mm; whereas it was -2.13 ± 1.39 mm for conventional one. Additionally, changes in RL of mandibular incisors in both groups were as - 0.26 ± 0.23 mm and -0.29 ± 0.27 mm; respectively. Moreover, appraisal of magnitude of LAB loss and root resorption of mandibular incisors within each archwire group revealed no statistically significant differences (p> 0.05).
Conclusion: Both coaxial multistrand and conventional NiTi archwires produced comparable minimal degrees of LAB loss and root resorption of mandibular incisors. In addition, no archwire was superior in reducing the incidence of either LAB loss or root resorption during leveling and alignment stage.