Application of Twin-Block Appliance in the Treatment of Skeletal ClassⅡmaloc-clusion

Class II skeletal malocclusion has a high incidence rate, significantly impacting patients oral function and mental health, making early intervention crucial. The Twin-Block appliance, invented by Dr. Clark in 1982, has seen substantial improvements in clinical application value through multiple iterations. The optimal timing for its use should be determined based on a comprehensive evaluation of the patients growth and developmental status, with better efficacy observed during adolescence and limited application in adult maxillary reconstruction. This appliance effectively improves the morphology of oral hard and soft tissues, upper airway function, and temporomandibular joint status, although studies on the upper airway are limited by small sample sizes. Compared to appliances such as Herbst and Activator, Twin-Block has both advantages and limitations, ne-cessitating clinical selection based on specific needs. This article synthesizes the latest domestic and international research findings to elaborate on the application and research progress of Twin-Block in treating Class II skeletal malocclusion. It covers the therapeutic principles, structural composition, evolutionary improvements, optimal timing for use, clinical outcomes, and comparative analysis with various removable appliances. These findings lay the foundation for the future development of Twin-Block toward digitalization, personalization, and precision, providing a scientific theoretical basis for optimizing clinical treatment plans for Class II skeletal malocclusion and exploring new approaches and directions for functional correction of this type of malocclusion.