ABSTRACT

To determine and compare change in the position and area of the upper and lower lips in patients with Class II division 2 malocclusion treated with and without tooth extraction.

This retrospective study included 40 female adolescent patients with Class II division 2 malocclusion who were divided into an extraction treatment group (group E, n=20) and a nonextraction treatment group (group NE, n=20). Pretreatment (T1) and posttreatment (T2) cephalometric variables, and upper-lower lip area (via digital planimeter) were measured on lateral cephalometric radiographs. For soft tissue profile area measurement the upper lip was divided into 2 parts (area 1 and 2), and the lower lip was divided into 3 parts (area 3, 4, and 5). The paired t test was used to determine intragroup differences, and the Student t test was used to determine intergroup differences.

Mean age in group E was 15.8 years vs 15.4 years in group NE. A wide range of individual responses to the treatment protocols were observed, and none of the skeletal or soft tissue changes differed significantly between the groups.

Despite great variability in posttreatment soft tissue changes—including area measurements—the mean values for all measurements were similar in group E and group NE. Nonetheless, due to the observed variation in soft tissue response, we think that treatment planning should be carefully tailored to the needs of each patient.