Is There Any Difference in the Outcome of Growth Modification Treatment Between Class II Division ۱ and ۲ Malocclusions?

Background: Class II malocclusion is one of the most common orthodontic problems that can be divided into class II division ۱ and division ۲. Considering the differences between the ۲ malocclusions, the present study was designed to compare the dentoskeletal changes caused by growth modification treatment. Methods: This retrospective study included ۵۲ patients (۲ groups) with class II division ۱ and ۲ malocclusions, who were within the age range of ۱۱-۱۳ years and were treated by growth modification. Initial and final cephalograms were analyzed by Dolphin software premium ۱۱.۸. In addition, ۷ cephalometric variables including SNA, SNB, ANB, SN-GOGN, inter-incisal angle, mandibular body length, and overbite were measured in traced cephalograms. Finally, treatment changes in each group were analyzed by paired t test and between-group comparison was assessed by independent t test. The significant level was considered as ۰.۰۵. Results: Based on the results of dentoskeletal changes in both groups, SNB, ANB, mandibular length, and overbite underwent significant changes during treatment in both groups. Further, the interincisal angle changed significantly in division ۲ group (P<۰.۰۰۰۱) and the final interincisal angle decreased significantly in class II division ۱ patients (P<۰.۰۲۵). The results further revealed that changes in SNB and interincisal angles were statistically significantly greater in division ۲ group compared to division ۱ group (P<۰.۰۲۱ and P<۰.۰۱۲, respectively). Finally, there was no statistically significant difference between the groups regarding the other variables. Conclusions: Overall, mandibular position changes more in class II division ۲ patients and the treatment appears to be more successful in this group.