Abstract
A 13-year-old girl presented for treatment due to dental crowding. Upon examination, horizontal impaction of her mandibular second molars could be detected. Based on the patient's chief complaint, along with the results of the examination and analysis, orthodontic treatment involving the extraction of four premolars was performed. The mechanism of activated extra-length (AEL) nickel-titanium (NiTi) archwires was employed for molar uprighting. This technique involved placing crimpable stops on NiTi archwires, with a spacing 2-3 mm wider than the inter-bracket distance between first and second molars, leveraging the inherent resilience of the archwires to facilitate the desired molar movement. Upon completion of the treatment, uprighting of the horizontally impacted second molars was successfully achieved, with all teeth properly aligned, leading to improved occlusal function and smile esthetics. This case report validates that the utilization of AEL NiTi archwires can accomplish uprighting of mesially tilted molars through a well-planned anchorage design.