Fig. 1

Advanced Mandibular Spring. A The design scheme of AMS. The AMS system consists of a nickel-titanium alloy spring, a guide sleeve, a safety bushing, a central shaft, a dynamic bar, and corresponding connectors. B Application of buttons with clear aligner. The button is fixed on the clear aligner as an adapter for the orthopedic force. C The spring of AMS is compressed to generate pushing force to the mandible and maxilla. The force can be adjusted by screwing the thread on the central shaft, and the six loops on the central shaft correspond to 0–5 N. The force is transmitted through the dynamic bar and guide sleeve, and then applied on aligners using connectors