MonoBlocks or Fixed Devices
However TMJ problem's are universally reported with them because they lock the jaw and mouth into a fixed position. Total disaster for bruxers.
They offer no adjustment, therefore they have to be remade if further protrusion is needed (which is common after a patient has worn a splint for a few months). The common complaint is "it worked ok at the start but I have started to snore again".
While they are cheap, the complications from side effects and costs associated with having to remake, make it expensive therapy.
Tend now only to be sold by mail order or advertised over the air or in papers. Not used often by Dental Sleep Dentists.