Socially acceptable prosthesis

It is interesting how some things are considered normal and even desirable, while other things of the same nature are no go.
Communication prosthesis
Prosthesis is one of such examples.

Prosthetic device usually associates with an ugly plastic arm or leg of a poor vet. However, much more people have prosthesis than one would normally think.
The first thing that comes to mind is artificial teeth. Two most prominent types of tooth prosthesis exist today: dentures and implants. When installed, they look practically the same. However, a dentures usually brings disgusting pictures of false teeth left in a glass of water overnight, while implants bring up the gleaming celebrities of Hollywood. Metal ceramic implants are desired by many.
Some even prefer to replace their healthy natural teeth with implants: they don’t get caries and always look great. This is particularly funny, since not long ago implants were nickel or gold-plated shiny metal things, and no one in their right mind would like to replace natural teeth with that.
The other fine example is fake breasts. They also have two main categories: breast prosthesis and breast implants.
The first one are normally used after mastectomy and perhaps are not as famous as false teeth, but fall into the same category: no one wants them. On the contrary, silicone breast implants are widely known to the general public. They are very popular and quite socially acceptable. Many admire silicone breasts and many people want them, both openly or secretly, for themselves or their partners. There was even a story about a woman, who cashed fake breast implants and surgery as a present for her daughter’s sixteenth birthday! Together, they actually waited impatiently till the kid turns sixteen, because the underage cannot receive cosmetic surgery.
People rip off natural teeth and breasts to get fake ones.
Some may say that this is obvious: people want them, cause those implants look better than natural.
Well, here’s the point: no one wants a limb prosthetic, no matter how advanced it is.
Even if the artificial finger or arm or leg looks like real and presents some additional features, no one would rip out their own limbs to get the enhancement.
Once again, it looks like it is okay to implant artificial stuff to get looks, but people having no option but to use prosthesis to get default functions only receive stares. What’s wrong with our society?