The real culprit of a failed rhinoplasty is your lifelong friend, protector, and provider —- of your immune system that follows you around, stays with you, and protects you all the time without you knowing it, helps you fight off external germs, helps you repair wounds, and even makes you different from others. Since you came into the world, your immune system will be working silently with the rules they follow until you leave this world. We know so little about this system that several Nobel Prizes in medicine have been awarded to great scientists who have helped us understand a little bit about their internal rules. Another virus, —- HIV, is the reason why people talk about it, because it can shut down the whole system in a way we don’t know, not only to protect the virus itself, but also to expose people to a dangerous external environment. This is what we often call “AIDS” – AIDS, acquired immune deficiency syndrome. As far as we know about the immune system, at least one thing is certain: the immune system will attack a “foreign object” that invades the body – something that is completely outside of you – in full force, with a simple goal: to get it out of the body! This attack, when magnified to a scale we can see, is tantamount to a gruesome battle. The immune cells take turns, and those in front of them, if unsuccessful, either secrete themselves or resort to self-destruction, sending out their intracellular inflammatory mediators like flares to attract more immune cells to the battle ….. As a result, there will be local “redness”: blood vessels are heavily congested to bring in more troops to fight; “swelling”: inflammatory mediators lead to increased secretion of tissue interstitial; “heat”: skin temperature is increased due to increased blood flow; “pain”: inflammatory mediators stimulate the nerve endings and tell the brain center that there is a battle here. In most cases, the immune system wins —- foreign bodies are expelled, accompanied by a large amount of pus and necrotic tissue. Only then does the body clean up the battlefield and rebuild after the war with scar tissue. Sometimes the immune system can’t win, and one reason is: the foreign body is too big! For example, silicone and tumescent placed under the skin, they are chemically stable and do not degrade, like airborne troops infiltrating behind enemy lines, they do not scream and shout themselves, and there are fewer immune cells that know a foreign body has come here. But the skirmishes will still continue. Immune cells attack, inflammatory mediators stimulate, surrounding tissues repair… And so the cycle repeats until they are surrounded by a layer of white scar tissue visible to the naked eye – the envelope. The tissue sometimes fools itself and wraps the foreign body in this membrane, and it thinks it doesn’t count as a loss. At this point, the destruction of the inflammatory response and the repair of the organism come into balance, and the two sides appear, on the surface, to be living together peacefully. However, the small-scale inflammatory reaction will never stop, and it will stay with you for life. Specifically for the procedure of rhinoplasty, understanding the mutual balance between the immune system and the prosthesis, it is also possible to understand why the skin thins and the contouring becomes obvious after decades of silicone rhinoplasty and why the expansion has a long term infection. This chronic inflammatory reaction of a very mild degree, accumulating over time, will gradually thin the skin. And in the tip of the nose, the place of greatest tension, blood flow is already poor, the speed of repair can not keep up with the speed of destruction, the inherent tension and the case will wear out. Therefore, the long prosthesis is only an “external” cause, but it is the chronic inflammatory reaction of the immune system to the foreign body that causes the local skin thinning that is the real “internal” cause. Why doesn’t the rib cartilage wear out? It is because autologous rib cartilage simply does not cause the inflammatory reaction described above. Even if a very short nose is lengthened a lot or a very short tip is raised a lot, the skin is not attacked by the autoimmune system. It’s like a pregnant woman with triplets, whose belly is stretched out, but the baby will never come through the belly either. Why does allograft rib cartilage resorb? Because before allogeneic rib cartilage can be commercialized, all living cells and antigens in the rib cartilage must be removed with radiation —- so as to reduce the possibility of an immune reaction after transplantation. But because our organism’s recognition mechanism for foreign substances is far beyond our imagination, this immune reaction still cannot be eliminated. After the rate of destruction is great and the repaired cells are removed, this material must gradually become smaller and absorbed. Why must cartilage be used for the tip of the nose and allogeneic material can be used for the dorsum of the nose? It is because cartilage without inflammatory reaction is used in the weakest part of the tip, which shares most of the tension from the skin, while the prosthesis only plays the role of “filling”. Although there will be some thinning of the skin on the back of the nose in the long term, there is no weakest point from which the prosthesis can penetrate. Why is it not advisable to place ear cartilage in the L-shaped silicone prosthesis at the turn? Because ear cartilage depends on the nutrition of tissue fluid to survive. When it is a non-viable foreign body on one side, not only is there no nutrition coming from this side, but it will also be attacked by the immune system and will gradually become thinner – the legendary “resorption”. Therefore, the modern rhinoplasty concept, emphasizing the “structural support”, all the key structural parts that affect the shape of the nose, should be strengthened with autologous cartilage, in order to ensure long-term safety and stability. The allograft material, as an auxiliary material, can be used to “fill” the areas without tension, which is the real reason for the success of rhinoplasty.