Differences in hard and soft tissue profile after orthodontic treatment with and without extraction

Premolar extraction is often associated with variations in the soft tissue profile that lead to considerable improvements in the facial profile. This study compared the changes in the facial profile of hard and soft tissues and investigated possible differences in the various facial parameters between patients who were treated with and without premolar extraction.

A total of 98 orthodontically treated patients were divided into two groups with an equal number of participants. Premolar extraction was performed in the test group only. A total of 33 landmarks were identified on each cephalometric radiograph. The intraclass correlation coefficient was calculated. We evaluated changes in measurements between pre- and post-treatment by performing the signed-rank test. We used the Kruskal-Wallis test to compare changes between the groups.

No significant differences were observed in the treatment outcomes of skeletal and soft tissue variables in class I and class II participants between the test and control groups (P > 0.01). However, significant differences were noted in the treatment outcomes of dental variables in class II participants between the groups. Dental variables did not show any significant difference in class III patients between the groups.

This study showed that skeletal and soft tissue changes were similar in skeletal except for few dental parameters following orthodontic treatment with and without premolar extraction.