Cephalometric evaluation of soft tissue changes after extraction of upper first premolars in class II div 1 patients

摘要

Introduction: Tooth extraction to provide sufficient space, or camouflage of underlying skeletal problems is quitecommon in orthodontics. The present study evaluated soft tissue changes after upper first premolars extraction inclass II div 1 patients.Material and Methods: 20 cases (15 females, 5 males), with a mean age of 17.8±2.9 years with class II div1 malocclusion and normal vertical height, who needed upper first premolars extraction were selected. Pre- and post-treatment lateral cephalometric radiographs were digitized. Image analysis was conducted by View Box 3.1.1software. Paired t-test was used for comparison of pre- and post-treatment results.Results: The relationship of upper and lower lip to E-line and B-line had significant reduction. Dental variablesof U1-NA(mm), U1-NA(°), overjet and overbite showed statistically significant reduction. Interincisal angle hadsignificant increase. There were no significant difference in lower incisor variables and skeletal variables like SN-GoGn and FMA.Conclusions: Extraction of upper first premolars in patients with class II div 1 malocclusion resulted in normalposition of lips as presented by Holdaway, Legan and Ricketts which play a role in aesthetic profile. However, theamount of lip retraction was different from patient to patient.