What are my options to fix dent in the side of nose after Rhinoplasty?

Great question, for small imperfections in the nose before or even after a rhinoplasty, a HA filler like restalyn or Juvederm can work very well, lasts for years and typically very little is used. Good luck in your recovery and way to soon to judge the final result.

Your surgeon can feel this area and give you an idea of whether it is swelling or a depressed nasal bone.  If the dent remains then a limited revision surgery should be able to address the problem. 

I see what you are talking about and since you are early in the healing process, it is hard to say if it is due to swelling or the underlying structure. I would recommend giving it some more time for the swelling to go down and discuss it with your surgeon. Swelling can be asymmetric and can cause these little irregularities. At about six months, most of the swelling will be gone and you will have a better idea of where you will be long term and what to do. Best of luck