The real invisible appliance 1945 was first put forward by American doctor Catherine. China Shanghai Zhengya Dental Technology Co., Ltd. owns independent intellectual property rights. R&D started in 2004 and won many awards with the support of the National Venture Fund. Now it has been fully put into clinical use. This orthodontic method can know the whole process of orthodontic treatment in advance through the digital mode of computer, and the patient's teeth are corrected unconsciously through a pair of transparent appliances. This method can also be called "contact lens" for teeth.