Orthodontic appliances; orthodontic aids, including orthodontic training appliances which assist in straightening teeth, correcting arch development, improving jaw growth and facial development, braces for teeth, dental bite trays, dental plates, teeth retainers; dental apparatus, including, dental handpieces, dental impression trays, dental inlays; training devices for teeth, tongues and facial muscles; none of the foregoing being furniture for medical and dental purposes, or parts and fittings therefor