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.