Effect of Timing of Third Molar Extraction on the Rate of Mandibular En Masse Distalization Using Buccal Shelf Implants – A Randomized Controlled Trial

Abstract

This randomized controlled trial evaluates the impact of the timing of third molar extractions on the rate of mandibular en masse distalization and second molar angulation in orthodontic treatment, using buccal shelf implants in borderline Class III malocclusion patients. Late third molar extractions performed less than two weeks before distalization were compared to early extractions, performed six months prior, to investigate the effect of Regional Acceleratory Phenomenon (RAP) on tooth movement. The study also assessed second molar angulation changes, examining distal tipping differences between groups. Results showed a significantly faster rate of distalization in Group II (late extraction) at 0.637 ± 0.098 mm/month, compared to Group I (early extraction) at 0.422 ± 0.075 mm/month. Additionally, Group I experienced significantly greater second molar distal tipping (9.14°) than Group II (3.47°). These findings suggest that the timing of third molar extractions affects both distalization rates and second molar angulation, with early extraction offering a clinical advantage by leveraging RAP and minimizing undesirable tipping.