Root Shortening With Three Methods of Upper Front Teeth Retraction

External apical root resorption is a possible side effect of fixed orthodontic treatment, particularly in the upper front teeth. This randomized clinical trial was conducted to compare the amount and timing of root resorption associated with three different methods of retracting the upper anterior teeth using miniscrew anchorage. Sixty adult patients with Class II Division 1 malocclusion who required extraction of the upper first premolars were randomly allocated to one of three groups: a bidimensional bracket group, a hybrid dual-section archwire group, or a conventional sliding mechanics group. In all groups, the six upper anterior teeth were retracted together with the support of orthodontic miniscrews. Panoramic radiographs were obtained before treatment, after completion of leveling and alignment, and after completion of en-masse retraction. Root and crown lengths were measured on these radiographs to estimate external apical root resorption during the leveling and alignment phase, during the retraction phase, and over the complete observation period. The study also compared the pattern of resorption among the upper canines, lateral incisors, and central incisors.

Inclusion Criteria: * Adults aged 18-30 years. * Class II Division 1 dental malocclusion according to Angle classification * Mild-to-moderate skeletal Class II discrepancy, with an ANB angle greater than 4° and not exceeding 7°. * Overjet ranging from 5 to 9 mm. * Presence of all six maxillary anterior teeth. * Maxillary anterior teeth fully erupted and with complete root formation. Exclusion Criteria: * Patients with previous orthodontic treatment. * Missing permanent maxillary teeth. * Active periodontal disease. * History of trauma to any maxillary anterior tooth. * Previous endodontic treatment of any maxillary anterior tooth. * Periapical pathology involving any maxillary anterior tooth. * Extensive coronal restorations that could interfere with crown-length measurement. * Radiographic evidence of pre-existing root resorption before orthodontic treatment.