A Comparison of Changes in Mandibular Third Molar Angular and Linear Parameters in Non-extraction and First Premolar Extraction Cases Following Standard Preadjusted Edgewise Appliance Therapy: A Retrospective Orthopantomographic Study

Introduction The positional development of the mandibular third molars is influenced by orthodontic treatment mechanics and space availability. The impact of first premolar extractions on third molar angulation remains a subject of clinical interest, particularly in assessing whether the mesial movement of the buccal segment creates a favorable eruption pathway. Objective This retrospective study aimed to evaluate the effect of first premolar extractions on the angular and linear positional changes of the developing mandibular third molars following orthodontic treatment with a preadjusted edgewise appliance (PEA) [McLaughlin, Bennett, and Trevisi (MBT) prescription]. Methodology Pre-treatment (T1) and post-treatment (T2) orthopantomographs of 60 patients were analyzed, with 30 patients undergoing first premolar extractions, and 30 were treated with a non-extraction approach. Changes in mandibular third molar angulation and space availability were assessed. A paired t -test was used for intra-group comparisons, while an unpaired t -test was employed for inter-group analysis. Results The extraction group exhibited a statistically significant improvement in third molar angulation, with a mean change of 6.3° in the right quadrant and 8.9° in the left quadrant ( P < .05). In contrast, the non-extraction group demonstrated minimal angular changes, with a mean deterioration of −2.6° on the right and a non-significant mean increase of 1.7° on the left. Greater space availability was noted in the extraction group compared to the non-extraction group. Conclusion Premolar extractions in preadolescent orthodontic patients facilitate the mesial migration of the mandibular buccal segment, contributing to improved third molar angulation. This favorable positional change may enhance the likelihood of third molar eruption in an acceptable alignment, underscoring the potential benefits of extraction therapy in orthodontic treatment planning.