Prostheses come in many varieties, such as spacers or resurfacing prostheses. A team has developed digital musical instruments in the form of prosthesis, called Musical Prostheses. Penile prostheses are used to treat erectile dysfunction. This occurs most commonly on intravenous catheters and on medical prostheses. Some restorative applications include supporting crowns, bridges, or dental prostheses. Limb prostheses include both upper- and lower-extremity prostheses. This giant cell is often found in tissue because of medical devices, prostheses, and biomaterials. One type of these biosensors are employed in myoelectric prostheses. Common examples include prostheses, wheelchairs, and pain medications. This can include prostheses, orthotics, or wheelchairs. Whistled sibilants occur in speech pathology and may be caused by dental prostheses or orthodontics. These cement-less techniques may involve osseointegration, including porous metal prostheses. Prosthodontics is the dental specialty that focuses on dental prostheses. A few ocular prostheses today are made of cryolite glass. Cermets are also used in dentistry as a material for fillings and prostheses.