Abstract: Objective: To explore the orthodontic treatment effect for patient with bilateral impacted mandibular second molars and elongated maxillary molars. Methods: The treatment involved the use of resin ball with elastic wire traction, micro-implant anchorage, and intrusion arch. Results: After 33 months of treatment, bilateral mandibular second molars were successfully pulled in place and the elongated maxillary molars were effectively depressed, achieving good occlusal and proximal relationship. Conclusion: For patient with low-impacted mandibular second molars and elongated maxillary molars, the combination of resin ball with elastic wire traction, micro-implant anchorage, and intrusion arch can achieve simple and efficient correction.

Key words: impacted mandibular molar, molar reduction, micro-implant anchorage