The use of computerized 3-D technology in orthodontics has revolutionized the field of dentistry, with the introduction of the Invisalign trayless aligner in 1998. This computer-aided design and production of orthodontic appliances provides a more aesthetic and comfortable orthodontic treatment method for suitable patients. Although it has many shortcomings, it has attracted the attention of both patients and orthodontists. Researchers will be committed to its improvement, expanding its orthodontic indications and providing services to more patients. 1.Operation process Select Invisalign/Era Angel orthodontic technology at the initial consultation. Take records and working models, bite wax, take photos and X-rays, and then send the detailed information to Invisalign/Time Angel Orthodontic Appliance Production Center. The technician designs and produces a series of appliances using computerized 3-D technology, which is rather like a monomandibular orthodontic appliance, and the doctor participates in the correction. The patient comes back to the clinic and wears the orthodontic appliances 24 hours a day, replacing one pair in about two weeks, with a follow-up visit in 6 to 8 weeks. Generally, the treatment is completed in 9 to 15 months with 18 to 30 appliances. The final orthodontic appliance is also used as a retainer. 2 .Indications The indications of Invisible Braces without brackets are very narrow, and they are only suitable for the correction of mild malocclusion of adults or teenagers with complete eruption of the second permanent molar, such as mild crowding and a small amount of gap between teeth. It is not suitable for patients who need tooth extraction or intermaxillary traction. 3 . Advantages and disadvantages Invisalign/Era Angel is a colorless and transparent new material and new technology without bracket aligner, beautiful and comfortable is its most attractive feature, and can be removed when eating, rinsing and flossing, which is conducive to maintaining oral hygiene. Chairside operation time is short, light force is used during treatment, less root resorption and fewer emergencies. In addition, non-professional orthodontists can be trained by the Invisalign/Time Angel Training Center to participate in orthodontic treatment Invisalign/Time Angel Invisalign technology has narrow indications for orthodontic treatment. Requires complete cooperation from the patient. Difficult to move teeth as a whole. Expensive.