Aim: To compare the differences in inter-canine widths, lower incisor inclination, maxillary arch circumference as well as the periodontal changes between MBT and Roth prescriptions in class I malocclusion cases treated on non-extraction basis using 0.018inch brackets directly bonded according to bracket placement charts.

Methods: 20 patients allocated into one of two treatment groups in a parallel monocentric design with 1:1 allocation. 10 participants received MBT prescription brackets, while the other 10 participants received Roth prescription. Participants were of class I malocclusion, mild – moderate degree of crowding that required non extraction orthodontic treatment. Slot size 0.018x0.028-inch stainless steel brackets have been chosen for both groups. Brackets were directly bonded according to MBT bracket placement charts. Lower inter-canine width, maxillary arch circumference, mandibular incisor inclination and periodontal parameters were recorded. Repeated measures ANOVA test was used to study the changes by time within each group as well as to compare between the two groups. Bonferroni's post-hoc test was used for pair-wise comparisons when ANOVA test is significant.

Results: Roth showed statistically significant more decrease than MBT post treatment in maxillary arch circumference. The mandibular incisor inclination decreased significantly in the MBT group, while there was no statistically significant difference neither in inter-canine width nor in periodontal parameters between groups.

Conclusion: Both MBT and Roth resulted in favorable outcomes. MBT is recommended for cases where decreasing incisor inclination is needed, while Roth when decrease in the maxillary arch circumference is crucial.