This randomized controlled clinical trial will compare external apical root resorption in patients undergoing maxillary canine retraction using modified corticotomy-assisted frictionless T-loop mechanics versus conventional frictionless T-loop mechanics. Sixty orthodontic patients requiring extraction of maxillary first premolars will be randomly assigned to two groups. Changes in canine root length will be measured on panoramic radiographs taken before and after retraction to determine the extent of external apical root resorption. The study will evaluate whether modified corticotomy-assisted retraction results in different root resorption outcomes compared to conventional retraction.
Patients aged 12-30 years requiring canine retraction into maxillary first premolar extraction spaces
Patients with normal vertical skeletal pattern (mandibular plane angle 32° ± 5°)
Patients with healthy periodontium
Syndromic patients
Patients with systemic conditions requiring long-term medication affecting orthodontic tooth movement (e.g., NSAIDs, bisphosphonates, anticonvulsants)
Mixed dentition cases
Patients with pre-existing root resorption