Abstract: Dental appliances and methods for expanding the lower dental arch. The appliances may be removable mandibular expander devices for efficient arch expansion while being comfortable to wear and easy to use. The appliances may include a lingual portion that is shaped and sized to apply an expansion force to lingual surfaces of one or more teeth. The shape and size of the lingual portion may be configured to distribute the forces among posterior and/or anterior teeth.

Abstract: An interactive implementation method for mobile terminal display of 3D model, comprising the following steps of: 1. acquiring 3D model data from the data center, then optimizing the 3D model for reduction and putting the 3D model into the specified folder; 2. checking if the current environment is correct. If not, setting the environment; 3. importing into different layer areas according to different categories of 3D models; 4. creating a Point Light for each area, and naming the Point Light by which space to enter; 5. conducting material adaptation, generating a normal map for the 3D model and placing normal map in the normal map channel; 6. determining the mapping specification and mapping the 3D model in the import file; 7. importing the model upload background page into U3D, selecting the 3D model to be exported, calling up the corresponding upload option, generating Prefabs file from the 3D model and then uploading.