Does posture improve pectus excavatum as it you continue with good posture?

Hi expectus. Well you see my brother had PE when he was 14 years old. And, started working out before he reached 18 years old, and now i see his pic and he doesn't have pectus anymore. And, now i have pectus excavatum and im 13 years old except my brother was 1 year older. So, is it maybe the fact that my brother had good posture caused his PE to not be obviously shown anymore?

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