The most common fillers for this purpose now are HA's such as Restylane or Juvederm. These products have slightly different properties but both work for this purpose. It is more important to choose a qualified injector than the particular HA in my opinion. The advantages of these fillers for liquid rhinoplasty are that they are relatively smooth, moldable, produce less inflammation than thicker products, and if necessary they are reversible. Because there is not much motion in the nose the product can last a year or in some circumstances longer. The most common indications would be to smooth out a bump, change the rotation or projection of the nose. Fillers can work as sort of a rent with an option to buy meaning if you like the way the nose looks you could consider a rhinoplasty for a more permanent correction. However, these must be used with caution. There is a potential to create inflammation and contour irregularities if not injected properly. Further there are reported cases of skin necrosis when using fillers in the nose. These complications would make corrective surgery more difficult. If you absolutely do not want surgery fillers can be done safely but make sure you go to an experienced injector with knowledge of the products and the anatomy of the nose to limit the chance of these potential pitfalls.