As for the nose root bulge after prosthetic rhinoplasty, the most common cause may be infection or effusion.
The criterion of judgment is mainly based on the time of production. For example, within 7 days or half a month after operation, the root of the nose bulges. I think it should be bleeding, which means hematoma mixed with effusion.
If the operation has been done for a month or two or even a year, I think it should be an infection. Is there any infection in the nasal cavity, which leads to local exudation?
In another case, the prosthesis is displaced and arched, which may sometimes lead to the swelling of the mountain root. For example, we put the silicone for a long time, because it is tight at the tip of the nose, and sometimes the prosthesis may push up to the root of the nose, even a little higher than the nose, and may roll up, so sometimes it will form a bulge at this time. So when we find this phenomenon, we should find your surgeon as soon as possible. Your surgeon knows the situation best, so it's best for him to judge. The above is my answer, I hope it will help you.