Juvederm or other hyaluronic acid fillers work well for minor irregularities both before and after rhinoplasty. HA fillers can be expected to last around 6-9 months for this purpose. If longer duration is desired then permanentt microdroplet silicone injections could be considered.
Dermal fillers are often used on the nose to correct small defects, be it from birth, trauma or previous rhinoplasty. They are limited in their use but may balance out small irregularities. You want to make sure the injector has experience in this region.
Filler is best used for small touchups; in example, a subtle depression related to how the bone healed. I have also used it for patients with terribly twisted noses where after surgery there is still a slight difference from side to side. If it is anything more than a slight deformity, it is best to consider revision surgery.