[Analysis of root development of maxillary inverted impacted central incisor before and after orthodontic traction by CBCT].

PURPOSE: To investigate the changes of root development before and after orthodontic traction of maxillary inverted impacted central incisors using CBCT and Mimics software.

METHODS

Ten patients, who had a maxillary inverted impacted central incisor, were treated using a modified movable retractor combined with surgical eruption. Cone-beam computed tomography(CBCT) was taken before and after treatment. Mimics 21.0 software was used to reconstruct the impacted central incisors (the impacted teeth group) and the contralateral namesake teeth (the contralateral group) before and after treatment, and the tooth volume and surface area were calculated by the software. SPSS 26.0 software package was used for paired t test, to evaluate the root development before and after treatment.

RESULTS

All 10 patients were successfully treated,and the mean duration was (16.10±4.46) months. After treatment, the volume and surface area of teeth in the impacted teeth group were significantly increased compared with those before treatment(P＜0.01). The volume and surface area of the teeth before and after traction were significantly lower than those of the contralateral group(P＜0.01). However, during the treatment, there were no significant differences in the increase of tooth volume and surface area between the two groups(P＞0.05).

CONCLUSIONS

Modified movable retractor combined with surgical eruption can promote root development of maxillary inverted impacted tooth, which is a safe and reliable treatment method.