Assessment of facial profile changes in Class I biprotrusion adolescent subjects submitted to orthodontic treatment with extractions of four premolars

OBJECTIVE: To evaluate cephalometric changes in tooth and profile position in young adolescent individuals with Class I biprotrusion submitted to orthodontic treatment with extractions of four first premolars. METHODS: Pre and posttreatment lateral cephalometric radiographs from 20 patients with Class I biprotrusion malocclusion were used to evaluate the following measurements: nasolabial angle, distance from lips to E line, distance from lips, incisors, tip of the nose and soft tissue pogonion to Sy line. RESULTS: All measurements showed significant changes after treatment (p<0.05), except the distance from lips and soft tissue pogonion to Sy line. There was a positive correlation between the retraction of incisors and the change of upper and lower lips (0.803/0.925; p<0.001). CONCLUSION: The profile retrusion observed occurred more due to nose growth than to lips retraction. The response from soft tissues to incisors retraction showed a great variability