Effect of Early Versus Late Premolar Extraction on Orthodontic Tooth Movement

Overview

The goal of this randomized controlled trial is to evaluate whether the timing of premolar extraction affects the rate of orthodontic space closure during en-masse anterior retraction. The study will also assess gingival cleft formation, mesial movement of the upper first molars, ease and duration of premolar extraction, and patient-reported pain and anxiety. The main question it aims to answer is: Does early versus late premolar extraction affect the rate of orthodontic space closure? Researchers will compare two groups of patients. In the early extraction group the maxillary first premolars will be extracted before or within one week of start of fixed orthodontic treatment. In the late extraction group, the premolars will be extracted after alignment and immediately before the start of space closure. Participants will: * Receive fixed orthodontic treatment and bilateral extraction of the maxillary first premolars. * Be randomly assigned to either the early-extraction or late-extraction group. * Undergo orthodontic alignment followed by en-masse anterior retraction. * Have dental impressions/digital models obtained at the start of retraction and at 3 and 6 months to measure orthodontic tooth movement and space closure. * Be assessed for gingival clefts and mesial movement of the upper first molars. * Have the ease and duration of their premolar extraction recorded and report their pain and anxiety associated with the extraction procedure.

This randomized controlled trial will evaluate the effect of early versus late maxillary first premolar extraction on the rate of orthodontic space closure during en-masse anterior retraction. A total of 26 participants aged 13 to 25 years requiring bilateral maxillary first premolar extractions as part of their orthodontic treatment will be randomly allocated in a 1:1 ratio to an early-extraction or late-extraction group. In the early-extraction group, the maxillary first premolars will be extracted before or within one week of fixed appliance placement. Participants will subsequently undergo leveling and alignment, and en-masse anterior retraction will begin after stabilization on a 0.019 × 0.025-inch stainless steel archwire. In the late-extraction group, leveling and alignment will be completed first using the same archwire sequence. The maxillary first premolars will then be extracted immediately before initiation of en-masse anterior retraction. Thus, space closure will occur through relatively healed extraction sites in the early-extraction group and relatively fresh extraction sites in the late-extraction group. Orthodontic space closure will be assessed at baseline and at 3 and 6 months after initiation of retraction. Secondary assessments will include mesial movement of the maxillary first molars, incidence and severity of gingival clefts, ease and duration of premolar extraction, and patient-reported pain and anxiety. Digital models will be used to assess orthodontic tooth movement, while gingival clefts will be evaluated clinically.