[stefanix]

Made my own as well when I was interning at an othodontist.

There is not really much tech required. You can simply cut apart the gypsum model tooth by tooth and align it perfectly with wax and add space for you gum. Finally create a mold and use medical grade silicone to make the tooth straightener.

Silicone also allows for more movement and gives you control of upper and lower teeth in relation to each other.

While this is not rocket science there are considerations about jaw alignment that would be difficult for the amature to get right the first time around in any but simple misalignments.