這場演講聚焦於兒童的兩階段隱形矯正治療，從Phase I 的空間管理與常見挑戰開始，延伸到Phase II 的拔牙決策與臉型設計。透過數位模擬與CBCT的應用，結合實際病例的比較分析，探索隱形矯正在兒童領域中的新想法。如果你也曾在兒童隱形矯正 Phase I 療程後面對家長質疑「怎麼看起來變暴牙了？」，這場演講絕對切中痛點，本次將深入解析這個讓許多醫師困擾的問題，並分享如何用不同的設計與策略，讓治療走得更穩、更遠。

Maxillary incisor torque control is critical during space closure, particularly in cases of severe protrusion with minimal crowding. This presentation introduces the design, biomechanics, and clinical applications of the Double-J retractor—a customized appliance supported by palatal miniscrews that enables controlled, bodily retraction of the maxillary incisors. The force system is designed to direct the retraction force vector through the center of resistance of the anterior segment, while auxiliary torquing springs guided by palatal miniscrews provide additional torque control. Cephalometric superimpositions from clinical cases demonstrate excellent anchorage preservation, torque control, and vertical control, especially when combined with a transpalatal arch and cantilever clips. A finite element analysis was also conducted to examine the optimal placement of miniscrews and the magnitude of activation. The biomechanical principles of the Double-J retractor closely resemble those of Dr. Burstone’s torquing arch, making it an effective option for managing high-angle Class II protrusion cases with upright incisors and bony protrusion. Furthermore, this system allows for esthetic retraction without fixed appliances and may be integrated with clear aligner therapy, offering versatility in complex treatment scenarios.