Abstract: A tracing device for use in the mouth cavity can include an upper jaw plate, a lower jaw plate, and a coupling tool that connects the above jaw plates. The upper jaw plate can be provided with a guide prop stud, a stud installation pore, a tracing pin, a tracing pin installation pore as well as an auxiliary stud. The lower jaw plate can include a guide tracing table, a connection pore, as well as a movement line formation table. Different structures can be made of a magnetic material or associated with a magnet. A lower jaw inducement guide plate can be made of plastic and have three dimensional slopes, and a guide tracing table can have a tracing plate, and can be freely attachable/detachable to/from the main body of the lower jaw plate.