Assessment of Root Resorption Resulting from Orthodontic Treatment of Crowding with Fixed Lingual Orthodontic Appliances using Cone Beam Computed Tomography

Abstract

Background & Aim: this study aimed to evaluate the root resorption for incisors resulting from orthodontic treatment of  crowding with lingual appliances in comparison with labial appliances using CBCT.

Materials and Methods: The study sample consisted of 40 patients (24 female, 16 male) with class 1 malocclusion and moderate crowding of both the arches that could be treated on a non-extraction basis. They were randomly divided into two groups: Lingual appliances (20 patients, mean age 21.7 years) and the labial appliances (20 patients, mean age 20.9 years). The lengths of  maxillary and mandibular central and lateral incisors  were measured from CBCT images obtained before the treatment (T0) and at the end of the treatment   (T1).

Results: There was a significant decrease in the lengths of all teeth after treatment in both groups (P>0.05), where the resorption rate varied in the lingual group from 0.74 to 1.15 mm, and in the labial group from 0.43 to 0.70 mm. The rate of resorption in the lingual appliances was significantly greater than in the labial appliances of the central lower incisors (P = 0.001), lateral upper incisors (P = 0.016) and lateral lower incisors (P = 0.000), while there were no significant differences between the two groups for upper incisors (P=0.359).

Conclusions: The use of lingual and labial appliances is associated with root resorption after orthodontic treatment, but this resorption is clinically insignificant (<2mm). The lingual appliances also cause more resorption in the incisors compared to the labial appliances, especially for  central and lateral lower incisors and lateral upper incisors.