Hello, I assume you are referring to the nostril retainers that some surgeons (myself included) use after surgery to support your nostrils? These are different than the internal splints (Doyle splints) that are used after some rhinoplasties to support the bones and septum. For the nostril retainers, they are indeed used to reduce the risk of nostril shape asymmetry or collapse during the healing phase. The majority of patients would likely heal fine without them, however in my experience using them, the rate of nostril asymmetry is significantly improved with the extra support that they add. In summary, they aren't always required, but they certainly help reduce the chance of problems.