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

common in orthodontics. The present study evaluated soft tissue changes after upper first premolars extraction in
class ΙΙ div 1 patients.
Material and Methods: 20 cases (15 females, 5 males), with a mean age of 17.8±2.9 years with class ΙΙ div1 malocclusion
and normal vertical height, who needed upper first premolars extraction were selected. Pre- and posttreatment
lateral cephalometric radiographs were digitized. Image analysis was conducted by View Box 3.1.1
software. 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 variables
of U1-NA(mm), U1-NA(°), overjet and overbite showed statistically significant reduction. Interincisal angle had
significant increase. There were no significant difference in lower incisor variables and skeletal variables like SNGoGn
and FMA.
Conclusions: Extraction of upper first premolars in patients with class ΙΙ div 1 malocclusion resulted in normal
position of lips as presented by Holdaway, Legan and Ricketts which play a role in aesthetic profile. However, the
amount of lip retraction was different from patient to patient.