Yes, it is possible to have differences in nostril shape that can be either due to surgery, but can also be things you never noticed prior to surgery. Your surgeon should have a photo from the bottom view to analyze the nostril position and shape. Depending on the techniques used, he/she may have adjusted your cartilages, which also may contribute to nostril asymmetry. Lastly, if they did an open rhinoplasty, there are intranasal incisions that can heal and occasionally the scar tissue can pull the nostril opening in different ways, contributing to asymmetry. Discuss this with your doctor and ask for photos to follow up. Swelling can be a source as well, but should be normalizing in the 3-6 month time frame, and finally stabilizes by the 1 year mark. Hope that helps, Christopher C. Chang, MD Washington DC, Maryland, and Virginia