Premature loss of first permanent molars is a common occurrence in clinical practice, leading to abnormal occlusion and inefficient mastication for patients. This case report presented the orthodontic retreatment of a 32-year-old female patient who suffered from premature loss of mandibular bilateral first molars. The mesial tipping of the mandibular second molars led to an occlusal interference, resulting in a clockwise rotation of the lower jaw and an anterior open bite (AOB). We achieved long-distance molar mesialization using clear aligners with Albert cantilever arms. After 42 months of treatment, the patient's occlusion and facial profile significantly improved. The cantilever combined with the cleat aligner treatment has been clinically effective for the protraction of mandibular posterior teeth, extending the field of application of clear aligners.