Lip Area Changes in Adult Class II Division I Patients Treated with Premolar Extraction

Aim: This study aimed to evaluate the alterations in lip area before and after fixed orthodontic treatment in adult patients with Class II Division I malocclusion who underwent premolar extractions. Assessments were conducted using frontal photographs and measurements from lateral cephalograms focusing on dentoalveolar and soft tissue parameters.Methods: Twenty-three adult patients with Class II skeletal malocclusion were selected from the archive and pre and post-treatment lateral cephalograms in addition to frontal photographs were assessed. The same investigator manually traced both the cephalograms and photographs to minimize observer variability. Measurements were computed both manually and digitally for comparison purposes. Data were analyzed using paired t-test and p-value<۰.۰۵ was considered as significant.Results: The study found a significant increase in the thickness from the cervical portion of the upper incisors to the upper lip after treatment (mean pre-treatment: ۱۳.۷۰±۱.۹۲ mm; post-treatment: ۱۴.۳۷±۲.۱۸ mm; P=۰.۰۰۶). Conversely, the thickness from the lower incisors to the lower lip decreased significantly post-treatment (mean pre-treatment: ۱۶.۰۰±۲.۰۷ mm; post-treatment: ۱۴.۰۰±۲.۸۰ mm; P<۰.۰۰۱). Additionally, this study showed there were a significant decrease in vermilion height near to lip corners(p<۰.۰۵).Conclusion: Significant soft tissue changes were observed in adults with Class II skeletal malocclusion following orthodontic treatment involving premolar extractions. Notable changes included increased thickness from the cervical portion of the upper incisors to the upper lip, decreased thickness from the lower incisors to the lower lip, and significant decrease in vermilion height near to lip corners.

کلیدواژه ها:

Class II Malocclusion ، Lip area changes ، Photographic analysis