A comparative study of facial profiles in extraction and nonextraction treatment.

Evaluation of facial profiles and facial balance is a constant, continuous study and learning process for orthodontists. Tooth movement and proper positioning of the teeth to ensure favorable facial changes and to avoid unfavorable changes should be in the orthodontist's "diagnostic" mind from the very first examination. The continuous controversy concerning extraction of premolar teeth and its supposed effects on the facial profile led to the development of this study, which compares the pretreatment and posttreatment facial profiles of patients who underwent premolar extraction with those of patients who did not undergo extraction. The study comprised 170 consecutively treated patients. One hundred-eight of the patients were treated with premolar extraction, and 62 were treated without premolar extraction. The diagnostic extraction and treatment decisions were based on a total space analysis with differential extraction protocols. The Z-angle (an angular measurement) and the E-value (a linear measurement) were used to quantify and compare the pretreatment and posttreatment profiles of the two groups. Both groups completed treatment within the normal ranges of the profile measurement values with the lip profile position slightly more retrusive in the nonextraction group. The nonextraction group's posttreatment Z-angle was 5.27 degrees greater and the posttreatment E-value was 1.47 mm more negative than that of the extraction group. The extraction group began treatment with greater facial imbalance and had the greatest improvement in facial esthetics.