Why are my nostrils uneven? What is causing the tip of my nose to point to one side and look asymmetric? (photos)

I had a septorhinoplasty 3 months ago today. I had a very deviated septum previously. I also had a lump on one side of my nose caused by an injury to the face. The straightness of my nose is improved however I still feel it curves to one side slightly, causing one of my nostrils to be larger than the other. What is causing this asymmetry? I have seen my surgeon for follow up and he says my septum is still straight. Is there a revision procedure I can have to make the tip more symmetric?