Abstract: Objective: This case report presents a standardized treatment of a skeletal Class I malocclusion with crowded and protrusion using clear aligners. Diagnosis and Treatment: Following comprehensive diagnosis, difficulty assessment, treatment planning, and obtaining informed consent from the patient, extraction orthodontic treatment was performed using clear aligners. Key technical points included preparing posterior teeth for anchorage prior to space closure, employing a stepwise movement approach during space closure for canine distalization and incisor root control. Overcorrection was designed to counteract the “roller coaster” effect as much as possible. Results: The entire treatment involved one restart and a total of 73 steps. The patient’s facial profile improved significantly, occlusal relationships were satisfactory, no related complications were observed, and the patient expressed satisfaction with the treatment outcome. Conclusions: In extraction cases treated with clear aligners, it is essential to conduct anchorage design, vertical control, torque control, and overcorrection planning based on thorough diagnosis in order to minimize the risk of complications.

Key words: clear alingers, anchorage preparation, vertical control, torque control, overcorrection