Soft tissue changes associated with first premolar extractions in adult females

Abstract

Abstract Background The potential for premolar extractions to produce changes in the soft tissue profile after orthodontic treatment is controversial. Aim To evaluate the soft tissue changes associated with four first premolar extractions in adult females of South Indian ethnicity. Method Pre- and post-treatment lateral cephalometric radiographs of 30 adult female patients of South Indian ethnicity with bimaxillary dentoalveolar protrusion, requiring premolar extractions as a part of their orthodontic treatment, were used. The radiographs were traced and changes in three angular and 12 linear measurements measured relative to the perpendicular to the horizontal reference line, 7 degrees down from S-N through S. Correlation coefficients between the changes in the upper and lower incisors and the lip measurements were calculated. Results All linear and angular measurements, except for changes in upper and lower lip thickness, B’ point and the anterior point on the lower lip, showed statistically significant (p < 0.05) changes with treatment. A significant negative correlation was found between upper incisor change and nasolabial angle change and a significant positive correlation was found between upper incisor change and retraction of the most anterior point on the upper lip. Conclusion Extraction of the four first premolars followed by the retraction of incisors reduced the dental and soft tissue protrusion found in adult South Indian females with bimaxillary dentoalveolar protrusion.