Cosmetic surgery should only be available to those people with serious physical disfigurements

Obviously, or at least aparently, the main reason to do cosmetic surgery to anyone should be for a serious physical disfigurements caused by birth or by a car accident, for instance. What is more, even though I don´t understand very well the mental mechanism, it could be necessary if there is a person who feels like a man, but has a woman body. We can add this case of sexual identity on our cosmetic surgery list. But are these the only cases? I think these are undeniable, anyway. 
Nevertheless it´s not a sin to change some imperfect parts of our body by surgery, although most of the times is not necessary. This means that it is not a question of life or death or an extreme case of ugliness, therefore shouldn´t be available in those cases through public health service. Furthermore there are other alternatives if you want to look more attractive as cosmetic products, spa therapy, sticking to a low fat diet, giving up smoking etc. In other words, being operated on should be your last option to make yourself beautiful than you think you are, because of the risks chiefly.
It´s a good idea to think about your real motivations deeply before doing it because your choice is made sometimes based on people´s opinion about us or the opinion we think other have about us. It might be not worth it in this case. So if your self-esteem is safe and high in any case and the plastic surgery is only a question of your own aesthetic taste it could be reasonable, but according to your tastes you must pay for it if you can afford it. 
To sum up cosmetic surgery sometimes is a necessity and sometimes is a method to see yourself or feel better. But if you have complexes you should go first to see a psychologist and only later to see a cosmetic surgeon.