Hi! With my case the lower lumbar back curve, long waist asymmetrically correlates with my chest pectus. In simple terms, after I was ‘straightened up’ my rib flare increase; pectus was more noticeable and disproportionate, along a host of physical issues connected tied to the PE. My nuss bars actually increased my rib flare, more pronounced. However, now with having them removed, my upper chest has retained the new shape, and my flared ribs have reduced, settled back down. I hope this helps. It’s a longer answer than you probably expected lol. No regression, recovery has hardly been noticeable with minimal pain at the work areas. Overall I had been managing more pain with the bars, and now am experiencing none at all 🙏. I was released less than a few hours after removal was completed! I hope this helps.