Changes in soft tissue profile during and after orthodontic treatment

The intention of the study was to evaluate the soft tissue response to four premolar extraction and non-extraction treatment in patients with Angle Class II, division 1 malocclusions. Both groups included thirty patients. The data were obtained from lateral cephalograms taken before active treatment at the end of active treatment and 3–5 years after the end of retention. During treatment the lower lip and chin area was protruded in the non-extraction group. In both groups the depth of the nose increased, and so did the thickness of the basal part of the upper lip. The soft tissue profile excluding the nose straightened out, whereas the profile convexity increased when the nose was included. The nasolabial angle increased in both groups. There was a significant relapse of the overjet and overbite in the post-retention period. These changes were not reflected by changes in the position of the lips. There was a retrusion of the lips when related to the E-line as a result of the continuous growth of the nose. A post-treatment comparison revealed a very similar morphology in the two groups.