Niger J Clin Pract
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Comparative Study
Comparison of arch width changes following orthodontic treatment with and without extraction using three-dimensional models.
To compare the arch width changes in patients treated fixed orthodontic mechanics without extraction (Group 1), with upper and lower first premolar extractions (Group 2), and with upper first premolar extraction only (Group 3). ⋯ Extraction treatment mechanics did not cause narrow dental arches, but nonextraction treatment increased arch width in all 3 measurements. Treatments with only upper arch extraction showed similar results with nonextraction treatment.