Evaluation of root length following treatment with clear aligners and two different fixed orthodontic appliances. A pilot study

OBJECTIVES: The purpose of this pilot study was to evaluate the root lengths of upper incisors as an indication of the degree of orthodontically-induced apical root resorption following treatment with Smart Track® aligners and compare it with two different fixed orthodontic appliances – regular and Damon brackets – using cone-beam computerized tomography (CBCT). MATERIALS AND METHODS: The sample comprised 33 patients with class I malocclusion and 4–6 mm crowding divided in 3 groups; Group I: 11 patients treated with Smart Track® aligners, group II: 11 patients treated with Damon brackets, and group III: 11 patients with regular brackets. Maxillary incisors teeth lengths were assessed using Dolphin imaging software before and after treatment. All data were analyzed using analysis of variance and t-test. RESULTS: All groups showed statistically significant root resorption, 0–1.4 mm for clear aligners, 0.1–2.3 mm for Damon, and 0–2.5 mm for regular brackets group. However, cases treated with fixed appliance in general showed significantly higher resorption than those treated with Smart Track® aligners (P < 0.05). CONCLUSION: Orthodontically-induced root resorption, as evaluated by root length, is an inevitable drawback with different orthodontic techniques. However, the use of Smart Track® aligners showed less root resorption relative to regular fixed appliances