An Ambidirectional Cohort Evaluation of Soft Tissue and Dentoalveolar Changes after Orthodontic Treatment with Bimaxillary Distalization vs First Premolar Extraction.

AIM: To assess and compare the soft tissue profile and dentoalveolar changes associated with bimaxillary distalization to those associated with first premolar extraction.

METHODS

This was an ambidirectional, cohort study comprising of 40 subjects between 18 and 30 years of age of either gender, with well-aligned arches and incisor proclination. They were divided equally into two groups - group A underwent fixed orthodontic treatment with bimaxillary distalization and group B were treated by first premolar extraction with moderate anchorage. Changes in ANB, incisor inclination, molar distalization, and extrusion, as well as nasolabial angle and lip retraction, were assessed using pre- and posttreatment lateral cephalograms. Intra and intergroup comparisons were carried out by paired and independent tests, respectively. The threshold for statistical significance was set at p < 0.05.

RESULTS

Both groups showed significant improvements in the soft tissue profile and dentoalveolar values posttreatment. In group A, favorable changes in incisor inclination, lip retraction, and the nasolabial angle were observed, which were found to be statistically significant. Similar changes were observed in group B, in addition to a change in the ANB angle. On comparing treatment outcomes between the groups, statistically significant differences were seen in the mandibular plane angle, upper and lower incisor inclinations, and upper lip retraction (p = 0.005).

CONCLUSION

The changes produced by both treatment modalities were favorable with significant improvements. Although the changes seen in group A were slightly lesser than those seen in group B, they were comparable.

CLINICAL SIGNIFICANCE: To extract or not to extract has always been a dilemma orthodontists face, especially in borderline cases. The advent of extraradicular screws has largely simplified this problem since full arch distalization is now possible. This approach is particularly beneficial for patients hesitant about extractions or when extractions might undesirably flatten the facial profile. Considering the dearth of evidence, this study was taken up to compare treatment outcomes of a conventional premolar extraction approach vs a non-extraction approach with full arch distalization. The findings offer valuable insights for practitioners to make evidence-based treatment decisions. How to cite this article: Sanman R, Desai A, Natarajan S, et al. An Ambidirectional Cohort Evaluation of Soft Tissue and Dentoalveolar Changes after Orthodontic Treatment with Bimaxillary Distalization vs First Premolar Extraction. J Contemp Dent Pract 2025;26(7):699-704.