In the broad sense, plastic surgery is understood as that branch of surgery concerned with improving the appearance of patients by correcting anatomical imperfections or the external form of the body disfigured or destroyed by trauma or disease.
Understood in this way, plastic surgery includes numerous procedures that fall within other well-defined specialties, now completely detached from their common origin in general surgery, in which the aesthetic aim is intimately combined with that of functional restoration. This applies to orthopedics, which concerns itself with deformities of the locomotor system, as well as to orthognathodontics (dento-maxillo-facial orthopedics), which deals with dental malpositions and deformities of the maxillo-facial complex. While correcting alterations—whether excessive or deficient—in the development of the maxillary skeleton, it also restores important functions (respiration, mastication, phonation) and establishes better harmony of facial lines. Similarly, reconstructive plastic surgery of the facial features, destroyed or disfigured by trauma or congenital or acquired diseases, is a distinct specialty in its own right; it too has both aesthetic and functional aims. Plastic surgery is not limited to the face but extends to other regions where, for example, it may be necessary to remedy the aesthetic and functional consequences of cicatricial retraction from wounds.
It is now generally accepted that surgery pertaining to these specialties does not conflict with the laws of natural morality. On the contrary, objections are raised by some against those interventions whose indication is not based on the consequences of disease or congenital malformation but on the desire to improve the harmony of lines in the human person, altered by conditions that lie on the borderline between the normal and the pathological.
This type of surgery might be called "cosmetic surgery" (from κοσμέω = I adorn, beautify) if it were to be considered solely for its aesthetic function. But there is no doubt that the boundaries between plastic surgery and purely cosmetic surgery are extremely fluid, and that the latter, like the former, is at once aesthetic and functional. It includes, for example, the correction of the shape of the nose (saddle nose, hooked nose, etc.) and of the ear (lop ear), breast and abdominal plastics, the removal of wrinkles, and so on. Many of these conditions may be troublesome, giving rise to disorders or even true pathological states (e.g., hypertrophy of the breasts, excessive adiposity of the abdomen), and thus fall within the scope of plastic surgery; others, which do not appear to disturb any function, nevertheless disrupt the harmonious fusion of the various features that tend toward the ideal of human beauty and constitute the normotype (q.v.).
God, who created man without sin and in His image and likeness, must have shaped him as beautiful, and beauty should therefore be the norm; every deviation is to be regarded as the result of the transmission and perhaps the accentuation of degenerative traits. "Is beauty not a characteristic of the Divinity?" asks H. Bohn (op. cit., p. 500). It must be added that any deviation from the norm may hinder social life and be a source of dangerous psychological complexes. This also applies to the removal of wrinkles, a product of the loss of skin elasticity, a consequence and symptom of an incipient disease that appears prematurely, even in youth, and which men often regard as a condition of inferiority; hence, at least in many cases, an attempt to erase its signs is justified.
From the moral point of view, therefore, it must be concluded that, whenever the individual is not exposed to serious danger or harm (which can now be excluded for the vast majority of cases, provided they are treated by a skilled practitioner using correct technique), plastic surgery interventions—even when performed solely for cosmetic purposes—are intrinsically moral and therefore licit, provided the individual pursues an honestly subjective end.