No randomized controlled trial (RCT) has compared flapless corticision with the conventional treatment in the non-extraction treatment of crowded lower anterior teeth (LAT) in terms of external apical root resorption (EARR) and dehiscence formation (DF). The aim of this RCT was to investigate these two complications during levelling and alignment of the LAT using cone-beam computed tomography (CBCT) imaging.

Patients with mild to moderate crowding of the LAT were included. Subjects were randomly allocated to either the corticision-assisted orthodontic treatment group (CORT) or the traditional orthodontic treatment group (TRAD). In the CORT, three vertical incisions were performed after brackets’ placement. CBCT images were taken before starting treatment and after treatment completion to assess the EARR and the DF. Two-sample t-test and Chi-Square tests were used to detect significant differences.

In general, 312 roots of the lower anterior teeth (156 in each group) were examined. Fifty-two patients (14 males and 38 females, mean age 21.38) were recruited. (CORT; n=26, 6 males, 20 females, mean age 21.30); (TRAD; n=26, 8 males, 18 females, mean age 21.46). No statistically significant difference was found between the two groups regarding the overall mean value of EARR following alignment (P=0.436). The greatest recorded resorption values were 0.81 and 1.02 in the CORT and TRAD groups, respectively. At the end of levelling and alignment, there was no statistically significant difference between the two groups regarding the distribution of DF (P=0.780).

Corticision as an acceleration technique did not produce any significant side effects on the roots of lower anterior teeth and did not cause additional alveolar bone defects (dehiscence formation) compared to the conventional non-accelerated method of alignment.