Objective: To compare the magnitude of external apical root resorption (EARR) of incisors in patients undergoing the initial phase of orthodontic treatment with two sets of brackets. Materials and Methods: 18 Angle Class I patients (anterior crowding: 3 to 5 mm; mean age: 17.2 years) were included in the study and randomly divided into two groups: group I (n 9, MBT BRACKET) and group II (n 9, ROTH BRACKETS). The degree of EARR was detected in 144 upper and lower incisors by using cone-beam computed tomography (CBCT) scanned and measured. The scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between the groups were analyzed by nonpaired and paired t-test, respectively, with 5% significance level. Results: Significant differences were found for both groups between T1 and T2. No differences in the degree of EARR was detected. Conclusions: Although EARR has occurred in all teeth evaluated, the bracket design (MBT AND ROTH BRACKETS) did not demonstrate any influence on the results observed.