They are called prosthetics or supports.
If you are missing part of your tongue, it may affect speech, eating, and swallowing. It is important to work with a speech therapist and healthcare provider to develop strategies to improve these functions and adapt to the changes in your mouth.
neck
It is used to fix the bones of a body into a single plane so they don't move and repair in the right position. If you brake your leg and the brake is complex with many parts a uniplane fixation device is used to put everything in place and keep it there while the bone or bones repair. It can be identified as an odd amalgam of metal rods sticking out of a leg or arm with other rods connecting each of the protruding rods together. The rods that protrude from the surface of the body part are screwed into the bone, so there is a wound where the rod enters the body and needs constant attention. The device is taken off after a few months when the bone or bones have recovered.
Adduction is the movement of a body part toward the main axis of the body. This movement brings the body part closer to the midline of the body.
Abduction
Prosthesis/prosthetic
Candy is missing her left leg below the knee.
Handicapped is the term used, if some part is missing. disease is substituted by illness.
brain
In the series kyle xy the part that is missing is his belly button
a starfish is missing a few body parts like fins and tails
Arms.
Knee cap
regeneration
A fake arm is commonly referred to as a prosthetic arm or a prosthetic limb. It is an artificial device that replaces a missing body part, in this case, an arm.
It's called a deformity which is a missing part of the body or an extra part.