2. As far as therapeutic logic is concerned, Invisalign technique belongs to digital analog orthodontics. The more complex the dentition movement is, the more difficult the simulation is and the more prone to errors. The so-called "one short step makes an everlasting regret". For example, if you use the map of Gaode to navigate, with the increase of time and distance, the previous prediction will be more biased, unless you constantly re-test, which is also the advantage of Gaode road condition analysis. Then certified doctors in Invisalign play this role.

3. In materials science. Plastic or resin (Smartrack used in Invisalign) materials can never keep up with the biomechanical properties of metal materials. All instruments apply force through the deformation of materials. If the same force needs more deformation, the more difficult it is to grasp this "degree", the more it needs clinical experience and big data support.