Comparison of Apical Root Resorption in Patients Treated with Fixed Orthodontic Appliance and Clear Aligners: A Cone-beam Computed Tomography Study

Abstract

To carry out comparison of apical root resorption (ARR) in the fixed orthodontic appliance and clear aligners with the help of cone-beam computed tomography (CBCT) imaging. The study was conducted on 576 roots in 110 patients. These patients were divided into two groups such that each group consisted of 55 patients. A total of 288 roots were analyzed in each group. One group consisted of patients treated with the conventional fixed orthodontic appliance. Another group consisted of patients treated with clear aligners. Radiographic images were collected with the help of CBCT for each patient. One image was collected before treatment while another image was collected after treatment. The length of the root of the anterior tooth was measured with the help of CBCT images. The ARR was calculated for each tooth by obtaining the difference between the length of the root measured before orthodontic treatment and after orthodontic treatment. The data were recorded, and statistical analysis was carried out with the help of the paired t test and Chi-square test to compare ARR between the two groups. The ARR was more in patients who were treated with fixed orthodontic treatment than in those patients who were treated with clear aligners. The mean value of ARR in fixed orthodontic appliances was 1.51 ± 1.34 mm, whereas the mean value of ARR in clear aligners was 1.12 ± 1.34 mm. The severity of ARR in the clear aligners group (on average) was significantly less than that in the fixed appliances group (on average). It was found that ARR in each individual's tooth included in the study was more in case of the fixed orthodontic appliance as compared with clear aligners (p <0.001). From the present study, it can be concluded that the amount of resorption at the root apex is less among patients who undergo treatment using clear aligners as compared with those treated with conventional fixed orthodontics appliances. ARR found in the orthodontic treatment is a process that causes loss of hard dental tissues such as dentine and cementum at the root apex. Fixed orthodontic appliances are most common method of orthodontic treatment. However, clear aligners are also used commonly for orthodontic treatment.