Soft Tissue Profile Changes in Patients With Class II malocclusion

Background: The objective of this study was to identify the soft tissue profile outcomes of orthodontic treatment of Class II, division 1 malocclusion patients and to determine if these changes are related with different treatment protocol. Methods: The sample of this study consisted of 50 Caucasian patients [22 males; 28 females], with a mean age of 15.8 years. The sample was divided in two groups (both groups treated with multibracket therapy): first group was non-extraction group [25 patients] treated first with the Herbst appliance, and second group was four premolars extraction group [25 patients] treated with a multibracket appliance. The patients’ pre- and post-treatment profile photographs were used, and the soft tissue landmarks were identified. Afterwards, the angular parameters were determined on each photo. Paired-sample t-test was used for intragroup comparisons. For testing the differences in all parameter values between groups, two-sample t test was used. Results: The improvement in the non-extraction group was evident in the decrease of the nasomental angle [P=0.02], the angle representing the projection of the upper lip to the chin [P=0.01], as well as the upper lip angle [P=0.01]. On the other hand, the nasolabial angle increased significantly [P=0.01], as well as the mentolabial angle [P=0.02]. In the extraction group, the nasolabial angle showed a significant increase [P=0.03]. Two soft tissue variables showed significant differences between the groups: the total facial angle or facial convexity including the nose [P=0.04] and the angle presenting the projection of the upper lip to chin [P=0.01]. Conclusions: The patients treated without extractions showed a significant improvement of the convex profile and favorable soft tissue changes in the lower third of the face. The orthodontic treatment of Class II, division 1 malocclusions induce positive effects on the soft tissue facial profile, which depends on different treatment protocols.